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Daniele MALFERRARI
Professore Associato
Dipartimento di Scienze Chimiche e Geologiche - Sede Dipartimento di Scienze Chimiche e Geologiche
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Pubblicazioni
- ZeoLIFE, a project for water pollution reduction and water saving using a natural zeolitite cycle
[Relazione in Atti di Convegno]
M., Coltorti; D. D., Giuseppe; B., Faccini; E., Passaglia; Malferrari, Daniele; M., Mastrocicco; N., Colombani
abstract
ZeoLIFE, a project for water pollution reduction and water saving using a natural zeolitite cycle
2024
- An insight into REEs recovery from spent fluorescent lamps: Evaluation of the affinity of an NH4-13X zeolite towards Ce, La, Eu and Y
[Articolo su rivista]
Colombo, Francesco; Fantini, Riccardo; Di Renzo, Francesco; Malavasi, Gianluca; Malferrari, Daniele; Arletti, Rossella
abstract
The constantly increasing demand of Rare Earth Elements (REEs) made them to be part of the so-called "critical elements" indispensable for the energy transition. The monopoly of only a few countries, the so-called balance problem between demand and natural abundance, and the need to limit the environmental costs of their mining, stress the necessity of a recycling policy of these elements. Different methods have been tested for REEs recovery. Despite the well-known ion-exchange properties of zeolites, just few preliminary works investigated their application for REEs separation and recycle. In this work we present a double ion exchange experiment on a NH4-13X zeolite, aimed at the recovery of different REEs from solutions mimicking the composition of liquors obtained from the leaching of spent fluorescent lamps. The results showed that the zeolite was able to exchange all the REEs tested, but the exchange capacity was different: despite Y being the more concentrated REE in the solutions, the cation exchange was lower than less concentrated ones (16 atoms p.u.c. vs 21 atoms for Ce and La solutions), suggesting a possible selectivity. In order to recover REEs from the zeolite, a second exchange with an ammonium solution was performed. The analyses of the zeolites show that almost all of Ce and Eu remain in the zeolite, while nearly half of La and Y are released. This, once again, suggests a possible selective release of REEs and open the possibility for a recovery process in which Rare Earths can be effectively separated.
2024
- The origin and significance of euhedral apatite crystals on conodonts
[Articolo su rivista]
Malferrari, D.; Ferretti, A.; Medici, L.
abstract
Crystal overgrowth on fossil remains is well-documented in the literature. Attention has specifically focused on
bioapatite (i.e., an apatite of biochemical origin regardless of post-mortem changes) configurations, in order to
decipher any possible relation to fossilization/diagenesis. This study investigates the Rare Earth Element (REE)
and other High-Field-Strength Element (HFSE) composition of euhedral crystals formed on the surface of conodont elements compared with that of crystal-free surfaces. Euhedral crystals are by definition crystals characterized by sharp faces, developing solids that, for apatite, assume the form of hexagonal prisms, reflecting its crystal symmetry. Late Ordovician (Amorphognathus ordovicicus Zone) conodonts from two localities in Sardinia and the Carnic Alps (Italy) are herein investigated. Conodont elements reveal the occurrence of smooth surfaces and surfaces partially covered with euhedral crystals. Since euhedral crystals did not reasonably grow during the organism’s lifetime, the REE and HFSE analysis can provide important insights into the crystal growth process. The experimental results indicated a substantial contribution of diagenetic imprinting for all the analyzed material, although more evident on euhedral crystals that are significantly enriched in middle and, subordinately, in heavy REE with respect to smooth surfaces. The positive correlations between La + Th vs log[ΣREE] and Ce + Th
vs log[ΣREE] could support the hypothesis that the neoformed euhedral crystals grew also by depleting the pristine bioapatite of the conodont elements. Nevertheless, the occurrence of two types of apatite cannot be ruled out: euhedral crystals as neoformed products of diagenetic processes and smooth surfaces as remains of the pristine conodont bioapatite after diagenesis.
2023
- A multidisciplinary approach in recognizing seep-carbonates: A case study from the Loiano Formation (late Eocene) in the northern Apennines (Italy)
[Articolo su rivista]
Conti, S.; Panini, F.; Patteri, P.; Rondelli, R.; Malferrari, D.
abstract
2023
- To be or not to be a conodont. The controversial story of Pseudooneotodus and Eurytholia
[Articolo su rivista]
Ferretti, A.; Corradini, C.; Fakir, S.; Malferrari, D.; Medici, L.
abstract
The genus Pseudooneotodus (Drygant, 1974) is a genus of small and conical elements widely distributed from the Middle Ordovician to the Early Devonian throughout the world. Because of its unusual shape, Pseudooneotodus has long been considered enigmatic, and only in the late nineties of the last century the genus has been finally placed within conodonts according to histological data. This study investigates possible similarities between Pseudooneotodus and Eurytholia (Sutton et al., 2001), an incertae sedis genus of enigmatic plates with a phosphate composition. An association of over one hundred specimens of Pseudooneotodus beckmanni and Eurytholia bohemica was analyzed from conodont residues in two distinct geographical areas: the Prague Basin (Požáry and Mušlovka sections, Bohemia, Czech Republic) and the Carnic Alps (Rauchkofel Boden section, Austria). Through an investigation that combines the use of optical and electron microscopy (including focused ion beam scanning electron microscopy), X-ray microdiffraction, and trace element (HFSE) analysis by mass spectrometry, differences between these fossil groups were observed and compared with data resulting from typical conodonts (Dapsilodus obliquicostatus, Panderodus unicostatus and Wurmiella excavata) recovered from the same samples.
2023
- Waste By-Product of Grape Seed Oil Production: Chemical Characterization for Use as a Food and Feed Supplement
[Articolo su rivista]
D'Eusanio, Veronica; Malferrari, Daniele; Marchetti, Andrea; Roncaglia, Fabrizio; Tassi, Lorenzo
abstract
2022
- Innovative use of thermally treated cement-asbestos in the production of
foaming materials: Effect of composition, foaming agent, temperature and
reaction time
[Articolo su rivista]
Ligabue, MARIA LAURA; Saburit, Alejandro; Lusvardi, Gigliola; Malferrari, Daniele; Garcia-Ten, Javier; Monfort, Eliseo
abstract
The management of asbestos-containing wastes in European Union (EU) is still based on landfilling, which, in the
long term, may pose a problem of dispersion of their carcinogenic fibres into the air and water. Therefore, solutions
based on inertization of asbestos fibres and subsequent recycling are preferred. In this study, following
the principles of circular economy, thermally treated cement-asbestos (KRY⋅AS) and glass wastes (RG) were used
as main raw materials to manufacture foam glass, given its potential to incorporate waste materials. However,
the low carbon compound content of both raw materials and the high amount of thermostable crystalline phases
contained in KRY-AS made the introduction of foaming agents and powerful fluxing agents necessary. Contrary
to what was expected, the addition of Na2CO3 as fluxing agent was observed to be ineffective in the tested
compositions, because of the devitrification of crystalline phases, namely åkermanite (Ca2MgSi2O7) and combeite
(Na2Ca2Si3O9), which reduced the formation of vitreous phase, limiting the foaming process. Li2CO3 as
alternative fluxing agent was chosen, despite being aware of its current higher cost. The methodology developed
has allowed to investigate the influence of the RG:KRY⋅AS ratio, the type and content of the fluxing agents and
the content and size of the foaming agent (SiC), to establish the optimum firing conditions (maximum temperature
and soaking time), as well as to unveil the main foaming mechanisms involved. Finally, specimens with
good properties were obtained with a composition with high waste material content, namely (values in weight)
55% RG, 40% KRY-AS, 5% Li2CO3 as fluxing agent and 2.5% SiC-1500 as foaming agent, when fired at temperatures
and soaking times of 1100 ◦C and 1 min respectively. The obtained product presented values of
apparent density (0.55–0.68 g/cm3) and compressive strength (0.56 MPa) comparable with those reported in the
literature for foam glasses obtained from wastes and close to commercial foam glasses. Despite the technical and
economic limitations of the process, this work opens up new possibilities in a circular economy context for waste
materials which encountered serious problem to be recycled and mostly ended up in landfills
2021
- A time- and cost-saving method to check the point-to-point distribution of soil improvers
[Articolo su rivista]
Malferrari, D.; Laurora, A.; Brigatti, M. F.; Di Giuseppe, D.; Faccini, B.; Coltorti, M.
abstract
Background: In recent times, also in compliance with several sustainable agriculture rules, the use of soil conditioners, such as zeolites, progressively increased. Zeolites are minerals characterized by unique physical-chemical properties, which make them able to control the mobility of water, ammonium and other cations in soils. As zeolites do not exhaust their properties over time, it would be appropriate to check for their correct distribution in the amended soil. Aims: We present an efficient and inexpensive method to measure the point-to-point amount of zeolite spread in the soil through the analysis of a single (i.e., one peak) X-ray powder diffraction signal. Methods: The procedure requires the preparation of a calibration curve using known quantities of non-amended soil, zeolite and of an internal reference standard. The amount of zeolite is calculated by comparing the intensities of the selected signal in unknown sample with its analogue in the calibration curve. Results: The method returned a small underestimation (about 12 weight %) of the measured values compared to those expected which depend nearly exclusively on the valuation of the apparent density of the soil, whereas it is not affected by the type and number of phases present in the soil and in the amendant. Conclusions: The proposed method allows to check for the regular distribution of zeolite in soil, but we are confident that it could also be conveniently generalized to all the applications that require the quantitative determination of mono or polyphasic crystalline materials within a complex mixture like soil.
2021
- Al-Substituted Tobermorites: An Effective Cation Exchanger Synthesized from "end-of-Waste" Materials
[Articolo su rivista]
Malferrari, D.; Bernini, F.; Di Giuseppe, D.; Scognamiglio, V.; Gualtieri, A. F.
abstract
The policies to meet the "zero waste"regime and transition to sustainable circular economy can no longer ignore the use of wastes in place of natural resources, and these daunting and vital societal challenges are nowadays being faced by several nations. The main objective of this work was to search waste materials suitable for a quick and environmentally friendly production of a nanoporous geomaterial able to trap toxic metals at the solid/liquid interface. More specifically, the end-of-waste from the thermal inertization of cement-asbestos and glass powder from domestic glass containers have been employed as sources for the hydrothermal synthesis of a tobermorite-rich material (TRM) successfully tested for the selective removal of Pb2+, Zn2+, Cd2+, and Ni2+ from aqueous solutions. The synthesis was carried out in alkaline solution under mild hydrothermal conditions (120 °C) within 24 h. The quantitative phase analyses of the TRM carried out by applying the Rietveld method showed the occurrence of a large amount of well-crystallized 11 Å Al-substituted tobermorites and an amorphous phase and a lower content of aragonite and calcite. Chemical analyses and thermogravimetric measurements coupled with simultaneous evolved gas mass spectrometry highlighted that Al3+ for Si4+ substitutions in the wollastonite-like tetrahedral chains of tobermorites are balanced by the occurrence of Ca2+, Na+, and K+ cations in the interlayer rather than by (OH)- for O2- substitutions in the CaO polyhedra. Time-dependent removal tests clearly indicated that metal cations are selectively adsorbed depending on their concentration in solution. Moreover, the kinetic curves showed that the removal of metals from solution is fast and the equilibrium is almost reached in the first 8 h.
2021
- Characterization and assessment of the potential toxicity/pathogenicity of Russian commercial chrysotile
[Articolo su rivista]
Di Giuseppe, D.; Zoboli, A.; Nodari, L.; Pasquali, L.; Sala, O.; Ballirano, P.; Malferrari, D.; Raneri, S.; Hanuskova, M.; Gualtieri, A. F.
abstract
Today, cancer is one of the main health issues faced in the workplace, with asbestos an important carcinogen in the occupational environment. Among the asbestos minerals, chrysotile is the main species of socio-economic and industrial relevance. Although chrysotile asbestos is classified as a "carcinogenic substance"by the International Agency for Research on Cancer (IARC), this fiber is still mined and used in Russia. The effective health hazard posed by the Russian commercial chrysotile has not been quantitatively assessed to date. In this work, the potential toxicity/pathogenicity of Russian chrysotile was quantitatively determined using the fiber potential toxicity index (FPTI) model. This model was applied to a representative commercial chrysotile from the Orenburg region, Russia, whose morphometric, crystal-chemical, surface activity, and biodurability related parameters were determined. We have quantitatively assessed that the toxicity/pathogenicity potential of Russian chrysotile (FPTI = 2.4) is lower than that of amphibole asbestos species but higher than the threshold limit set for "safe"mineral fibers (FPTI = 2.0), although it does not contain impurities of amphibole asbestos. Differences with other chrysotile samples were discussed, and it was found that the investigated Russian commercial chrysotile shares several features with the Italian Balangero chrysotile, indicating that widespread concern on commercial Russian chrysotile is justified.
2021
- Characterization of fibrous wollastonite NYAD G in view of its use as negative standard for in vitro toxicity tests
[Articolo su rivista]
Di Giuseppe, D.; Scognamiglio, V.; Malferrari, D.; Nodari, L.; Pasquali, L.; Gualtieri, M. L.; Scarfi, S.; Mirata, S.; Tessari, U.; Hanuskova, M.; Gualtieri, A. F.
abstract
Today, despite considerable efforts undertaken by the scientific community, the mechanisms of carcinogenesis of mineral fibres remain poorly understood. A crucial role in disclosing the mechanisms of action of mineral fibres is played by in vitro and in vivo models. Such models require experimental design based on negative and positive controls. Commonly used positive controls are amosite and crocidolite UICC standards, while negative controls have not been identified so far. The extensive characterisation and assessment of toxicity/pathogenicity potential carried out in this work indicate that the commercial fibrous wollastonite NYAD G may be considered as a negative standard control for biological and biomedical tests involving mineral fibres. Preliminary in vitro tests suggest that wollastonite NYAD G is not genotoxic. This material is nearly pure and is characterized by very long (46.6 µm), thick (3.74 µm) and non-biodurable fibres with a low content of metals. According to the fibre potential toxicity index (FPTI) model, wollastonite NYAD G is an inert mineral fibre that is expected to exert a low biological response during in vitro/in vivo testing.
2021
- Commercial brucite, a worldwide used raw material deemed safe, can be contaminated by asbestos
[Articolo su rivista]
Malferrari, D.; Di Giuseppe, D.; Scognamiglio, V.; Gualtieri, A. F.
abstract
Brucite is a raw material used in several applications and worldwide traded. The main active deposits are located in North America, North Europe and China and the extracted material is worked and delivered all over the world without any particular precaution as it is considered a safe inert product. But is it really true? Applying a consolidated protocol of analysis for the detection and characterization of fibers, we found asbestos in a sample of commercial brucite. The analyzed material is primarily composed of plate-like crystals of brucite; nevertheless, chemical and mineralogical analyses revealed the presence of serpentine, while morphometric observation through electron microscopy confirmed the occurrence of respirable regulated chrysotile (serpentine asbestos) fibers. The individual fibers making up the chrysotile bundles have length >5 µm, width <3 µm, length/width ratio >3, and their concentration in the investigated product is 169 mg/kg (0.02 wt%). Although paragenesis of brucite with chrysotile has been known for a long time, never before was documented a commercial brucite, distributed worldwide, contaminated with asbestos. In the light of these results, we think that certification of the absence of asbestos should be imposed to the brucite mining companies and distributors; otherwise, users should always include a careful inspection on incoming materials, at least by electron microscopy, to rule out the occurrence of asbestos.
2021
- Dead, fossil or alive: Bioapatite diagenesis and fossilization
[Articolo su rivista]
Ferretti, A.; Medici, L.; Savioli, M.; Mascia, M. T.; Malferrari, D.
abstract
Calcium carbonate, silica and calcium phosphate have been selectively used by organisms in the production of mineralized hard parts throughout the Phanerozoic. Among these materials, bioapatite has enabled fundamental acquisitions in the evolution of life. Despite the remarkable biological success, the crystallography of bioapatite and the eventual modification of its lattice parameters over geological time have in contrast been scarcely investigated. In our study, we analyzed living, dead and fossil remains of both vertebrate and invertebrate organisms that biomineralized apatite, ranging from the Cambrian to the Recent, a time interval spanning over 500 million years. We detected in this way the bioapatite crystal features of the major phosphatic phyla (Brachiopoda, Arthropoda, Bryozoa, and Chordata: the latter including conodonts, cartilaginous and bony fishes, amphibians, reptiles, birds and mammals). Groups were investigated using either fossil or recent material (dead and/or alive, the former indicating organisms who died in recent times, the latter referring to material extracted from living organisms). The experimental results revealed that phosphatic materials from living, dead, and fossilized organisms have a distinct crystallographic signature. In fact, bioapatite in fossils is characterized by lower values of the crystal lattice cell parameter a (9.320–9.439 Å compared to 9.355–9.466 Å in dead and alive organisms), whereas the cell parameter c is less variable (6.857–6.911 Å for fossils and 6.861–6.902 Å for recent bioapatite); Student t-tests, applied to the means of these ranges of values (a¯=9.369 Å, c¯=6.887 Å, volume¯=523.6 Å3 for fossil values, a¯=9.415 Å, c¯=6.878 Å, volume¯=528.0 Å3 for recent values), highlighted significant differences between fossils and recent samples at a level p < 0.01 for the three cell parameters. These changes, which begin at the death of the organism and only stabilize in the ultimate stages of fossilization, mirror the isomorphic chemical substitutions within the crystal lattice and drive to a general decrease of the cell volume (i.e., the volume of the bioapatite hexagonal crystalline cell frame) over time, with an average reduction of 4.4 Å3 (0.8%) from alive to fossil organisms.
2021
- Gaseous heptanethiol removal by a fe3+-phenanthroline-kaolinite hybrid material
[Articolo su rivista]
Bernini, F.; Castellini, E.; Bighi, B.; Borsari, M.; Malferrari, D.; Brigatti, M. F.
abstract
Kaolinite functionalized by the μ-oxo Fe3+-phenanthroline complex (Fe+3Phen) was selected to test its ability to efficiently remove and store gaseous heptanethiol (HPT). Spectroscopic techniques, elemental analysis, and thermal analysis coupled with evolved gas mass spectrometry were employed to characterize the material before and after the exposure to the gas and to define the adsorption process. The amount of HPT trapped by the functionalized kaolinite after 60 days is 0.10940 moles per 100 g of kaolinite which, considering the amount of adsorbed Fe+3Phen (0.00114 moles per 100 g of kaolinite), means a thiol/Fe3+Phen molar ratio of about 100:1, a value much higher than those found in the past for Fe+3Phen functionalized montmorillonite and sepiolite. In addition, the process was found to be efficient also beyond 60 days. This significant removal of the smelly gas was explained by considering a continuous catalytic activity of Fe3+ toward the oxidation of thiol to disulfide.
2021
- Molecular structure and ammonia gas adsorption capacity of a Cu(II)-1,10-phenanthroline complex intercalated in montmorillonite by DFT simulations
[Articolo su rivista]
Sainz-Diaz, C. I.; Castellini, E.; Escamilla-Roa, E.; Bernini, F.; Malferrari, D.; Brigatti, M. F.; Borsari, M.
abstract
A hydrated complex of 1,10-phenanthroline with Cu2+ cation was intercalated in the interlayer space of montmorillonite. This intercalation occurs initially by through a cation exchange mechanism in which the charge of the complex cation compensates the excess of the negative charge of the interlayer, then, once the cation exchange capacity (CEC) value has been reached, by direct adsorption of the sulfate salt of this complex (i.e. the cation together with its sulfate counterion). This material has showed interesting entrapping properties of gaseous phases and a peculiar chemical reactivity. However, the complete characterization and explanation of the formation of these materials is difficult with only experimental techniques. Hence, we used computational methods at atomic level to know how are the molecular structure of these complexes and their adsorption capacity of ammonia inside the interlayer confined space of montmorillonite for a better understanding of the experimental behaviour. First Principles calculations were performed based on Density Functional Theory (DFT). The intercalation of the phenanthroline-Cu(II) complex inside the nanoconfined interlayer of montmorillonite is energetically favourable in the relative proportion observed experimentally, being a cation exchange process. The further adsorption of the sulfate salt of the phenanthroline-Cu complex is also energetically possible. The adsorption of ammonia molecules in these montmorillonite-phenanthroline-Cu complexes was also favourable according with experimental behaviour.
2021
- Occurrence and characterization of tremolite asbestos from the Mid Atlantic Ridge
[Articolo su rivista]
Di Giuseppe, D.; Perchiazzi, N.; Brunelli, D.; Giovanardi, T.; Nodari, L.; Della Ventura, G.; Malferrari, D.; Maia, M.; Gualtieri, A. F.
abstract
Tremolite is one of the most common amphibole species and, in the fibrous form (i.e., characterized by crystals/particles consisting of fibres with length > 5 µm, width < 3 µm and aspect ratio > 3), one of the six asbestos minerals. Until now the attention of crystallographers has focused only on samples from continental environment. Here we report the first chemical and structural data of a tremolite asbestos found along the Mid Atlantic Ridge (MAR) at the eastern intersection of the Romanche Transform Fault (Equatorial MAR). Tremolite is associated with chlorite and lizardite and was formed through the green shale facies lower than zeolite in a predominantly fluid system. MAR tremolite asbestos shows very slight deviations from the ideal crystal structure of tremolite. Differences in cation site partitioning were found with respect to tremolite asbestos from ophiolitic complexes, attributed to the different chemical–physical conditions during the mineral formation. In particular, oceanic tremolite asbestos is enriched in Al and Na, forming a trend clearly distinct from the continental tremolites.
2021
- Response to Tilic and Bartolomaeus's Commentary on the original Research Paper “Unravelling the ultrastructure and mineralogical composition of fireworm stinging bristles” (Zoology, 144)
[Articolo su rivista]
Righi, S.; Savioli, M.; Prevedelli, D.; Simonini, R.; Malferrari, D.
abstract
In their Commentary to our paper recently published in Zoology (Righi et al., 2021a), Tilic and Bartolomaeus question our findings that the chaetae of Hermodice carunculata (Annelida) are hollow and able to store and deliver venoms. They sustain the idea that inflammatory chemicals are secreted through epidermal glands and possibly exposed to predator trough wounds caused by the brittle chaetae. We provide evidence-based arguments in support of our considerations. The sample preparation procedures did not affect the native inner structure of unfixed fireworm chaetae, which is clearly hollow as supported by both ultrastructure observation and crystal-chemical analysis of constituents. Furthermore, our previous and more recent feeding bioassays and chemical analysis indicate both that chaetae retain strong deterrent capacities even when isolated from the body of H. carunculata, and that they contain venoms. The cellular mechanisms involved in fireworm chaeta storage and deliver of chemicals are still unstudied. We strongly believe that this lack of knowledge should draw further attention on H. carunculata biology, pursuing new hypotheses and studies based on the noteworthy information which has been obtained so far.
2021
- Self-Assembled Structures from Solid Cd(II) Acetate in Thiol/Ethanol Solutions: a Novel Type of Organic Chemical Garden
[Articolo su rivista]
Bernini, Fabrizio; Castellini, Elena; Sebastianelli, Lorenzo; Bighi, Beatrice; Ignacio Sainz-Díaz, Claro; Mucci, Adele; Malferrari, Daniele; Ranieri, Antonio; Franca Brigatti, Maria; Borsari, Marco
abstract
Cd(II) acetate in tablet form, immersed in ethanol solutions with a high concentration of heptanethiol (30-80 mM) was able to develop self-assembled sail-shaped structures. The solution in which the self-assembled structure is formed is totally organic (both solute and solvent), thus representing a unique case among organic Chemical Gardens. The constituting material for this new Chemical Garden (CG) is made of a single phase, namely a cadmium heptanethiolate with a microcrystalline structure consisting of a central cluster [CdnSn]. The morphological and structural features were studied using different techniques (SEM-EDS, elemental analysis, FT-IR, 113Cd MAS NMR, XRPD). A crystalline cell for the Cd(II) heptanethiolate cluster was obtained that completely differs from that of the solid phase precipitated by mixing an ethanol solution of Cd(II) acetate with heptanethiol. It follows that the conditions under which the formation of Cd(II) thiolate occurs (slowly from solid, quickly from solution) play a critical role in determining the nature and structure of the precipitating phase.
2021
- The Copper Chemical Garden as a Low Cost and Efficient Material for Breaking Down Air Pollution by Gaseous Ammonia
[Articolo su rivista]
Castellini, Elena; Bernini, Fabrizio; Sebastianelli, Lorenzo; Bighi, Beatrice; Ignacio Sainz-Diaz, Claro; Mucci, Adele; Malferrari, Daniele; Ranieri, Antonio; Gorni, Giulio; Marini, Carlo; Brigatti, Maria Franca; Borsari, Marco
abstract
Chemical garden (CG) from copper(II) sulfate, nitrate and chloride (CG CuSO4, CG Cu(NO3)2, CG CuCl2) were grown and characterized from the structural and compositional point of view using scanning electron microscopy, X-ray powder diffraction, elemental analysis, thermogravimetric analyses coupled with mass spectrometry, and DR (Diffuse Reflectance) UV-Vis-Nir spectroscopy. The main crystalline phases, controlled by the anion of the starting salt, were brochantite and kobyashevite for CG CuSO4, gerhardtite, rouaite and anthonyite for CG Cu(NO3)2, and atacamite for CG CuCl2. The materials were then exposed to ammonia vapors to test the effectiveness of their entrapping property. All materials proved to be very efficient and rapid in the uptake of ammonia which invariably results in the formation of a Cu(II)/NH3 complex. However, after a few tens of minutes, CG Cu(NO3)2 and CG CuCl2 release water and get wet, thereby resulting unsuitable for applications. Only CG CuSO4 keeps dry for at least 25 hours. This makes it a valid candidate for building devices for trapping ammonia and possibly other gases capable of interacting with Cu (II). The entrapment of ammonia by this material was also characterized by 1H and 29Si MAS-NMR XAS spectroscopies.
2021
- Unravelling the ultrastructure and mineralogical composition of fireworm stinging bristles
[Articolo su rivista]
Righi, S.; Savioli, M.; Prevedelli, D.; Simonini, R.; Malferrari, D.
abstract
Amphinomid fireworms are notorious for their stinging dorsal bristles (notochaetae), but it is still unclear whether the irritation they cause is merely mechanical or if the notochaetae contain toxins. Furthermore, although fireworm chaetae have always been described as calcareous, their composition has never been investigated to date and strong debates are ongoing on their internal structure. Unravelling the native ultrastructure and composition of fireworm chaetae is the first crucial step to assess whether the hypothesis of toxin vehiculation could be fully considered. We examined for the first time the chemical and mineralogical composition, the ultrastructure and the external structure of the dorsal and ventral chaetae of the large species Hermodice carunculata. All the measurements were carried out on samples prepared without the use of chemical reagents, except for those targeted to investigate if decalcification altered the ultrastructure of the chaetae. A crystal-chemical strategy, combining chemical, diffraction and thermal analyses clearly showed the occurrence of crystalline calcium carbonate and clusters of phosphatic amorphous material. Scanning electron micrographs and energy dispersive X-ray measurements showed that the dorsal chaetae have an extremely shallow insertion point in the body respect to the ventral chaetae, that could facilitate the release of the notochaetae in the environment. Their proximal part is characterized by canals with a hexagonal pattern rich in Ca and P, followed by a large cavity upwards. The harpoon-shaped ends and the central canals of the notochaetae completely disappeared after exposure to EDTA. The notochaetae are hollow and may be able to vehicle toxins. The absence of the honeycomb pattern in the distal part of the notochaetae and their slenderness probably contribute to their brittleness and high sensitivity to breakage on contact. These observations constitute keystone understandings to shed light on fireworm defensive and offensive capacities and their ecological success.
2021
- Zooming in REE and Other Trace Elements on Conodonts: Does Taxonomy Guide Diagenesis?
[Articolo su rivista]
Medici, Luca; Savioli, Martina; Ferretti, Annalisa; Malferrari, Daniele
abstract
Conodont elements are calcium phosphate (apatite structure) mineralized remains of the
cephalic feeding apparatus of an extinct marine organism. Due to the high affinity of apatite for rare
earth elements (REE) and other high field strength elements (HFSE), conodont elements were frequently
assumed to be a reliable archive of sea-water composition and changes that had occurred during
diagenesis. Likewise, the crystallinity index of bioapatite, i.e., the rate of crystallinity of biologically
mediated apatite, should be generally linearly dependent on diagenetic alteration as the greater (and
longer) the pressure and temperature to which a crystal is exposed, the greater the resulting crystallinity.
In this study, we detected the uptake of HFSE in conodont elements recovered from a single stratigraphic horizon in the Upper Ordovician of Normandy (France). Assuming therefore that all the specimens have undergone an identical diagenetic history, we have assessed whether conodont taxonomy (and morphology) impacts HFSE uptake and crystallinity index. We found that all conodont elements are characterized by a clear diagenetic signature, with minor but significant differences among taxa. These distinctions are evidenced also by the crystallinity index values which show positive correlations with some elements and, accordingly, with diagenesis; however, correlations with the crystallinity index strongly depend on the method adopted for its calculation.
2021
- ʻConodont pearlsʼ do not belong to conodonts
[Articolo su rivista]
Ferretti, A.; Malferrari, D.; Savioli, M.; Siepe, T.; Medici, L.
abstract
We investigated the mineralogical and chemical signatures of enigmatic microspherules commonly recovered in conodont residues and referred to in literature as ‘conodont pearls.’ Comparison between these ‘pearls,’ associated conodonts and other phosphatic skeletal elements present in the same stratigraphical level was run in an effort to reveal any possible relation between ‘conodont pearls’ and the joined groups so to finally provide a response on the affinity of these spherules.
2020
- A new material based on montmorillonite and Cu(II)-phenanthroline complex for effective capture of ammonia from gas phase
[Articolo su rivista]
Castellini, E.; Malferrari, D.; Bernini, F.; Bighi, B.; Mucci, A.; Sainz-Diaz, I. C.; Serrano, A.; Castro, G. R.; Brigatti, M. F.; Borsari, M.
abstract
The intercalation of [Cu(Phen)(H2O)2]2+ (CuPhen) in montmorillonite (Mt) produces a stable hybrid material that is very efficient in removing NH3 from gas phase even at extremely low pressures. The process was studied by elemental analysis, X-ray powder diffraction, thermal analysis coupled with evolved gas mass spectrometry and DR UV–Vis, NMR and X-ray absorption spectroscopy. The adsorption of CuPhen on Mt consists of two consecutive steps. During the first one, CuPhen intercalates alone into Mt through a cation exchange process, afterwards CuPhen and SO42− ions entry jointly into the mineral interlayer. The two-steps adsorption process is described by a VI-type isotherm, successfully fitted by two independent Frumkin isotherms. NH3 trapping is long-lasting, easy, fast even at extremely low gas pressure and reversible under mild conditions. Mt containing CuPhen always results well performant in removing ammonia from gas phase, but an appreciably higher adsorption capacity of NH3 is obtained when SO42− ion is absent from the interlayer. This hybrid montmorillonite is thus a promising material to be used in industrial or environmental contexts, as an efficient air-cleaner.
2020
- Electrochemical data on redox properties of human Cofilin-2 and its Mutant S3D
[Articolo su rivista]
Pignataro, M.; Di Rocco, G.; Lancellotti, L.; Bernini, F.; Subramanian, K.; Castellini, E.; Bortolotti, C. A.; Malferrari, D.; Moro, D.; Valdrè, G.; Borsari, M.; del Monte, F.
abstract
The reported data are related to a research paper entitled "Phosphorylated cofilin-2 is more prone to oxidative modifications on Cys39 and favors amyloid fibril formation" [1]. Info about the formation and redox properties of the disulfide bridge of a protein is quite difficult to obtain and only in a few cases was it possible to observe a cyclic voltammetry (CV) signal [2,3]. Human cofilin-2 contains two cysteines (Cys39 and Cys80) which can be oxidized in suitable conditions and form a disulfide bridge [1]. For this purpose, CV measurements were carried out on human cofilin-2 WT and its mutant S3D immobilized on a gold electrode coated by an anionic self-assembled monolayer (SAM), after a pre-oxidation time which was fundamental for observing a CV signal relating to the oxidation/reduction process of the disulfide bridge of the proteins. The data include CV curves obtained with and without electrochemical pre-oxidation and after oxidation with H2O2. In addition, the plot of the cathodic peak current vs. electrochemical pre-oxidation time and the pH dependence of the formal potential (E°’) are reported. The data obtained by CV measurements were used to determine the time required to form the disulfide bridge for the immobilized proteins and, consequently, to observe the CV signal, to calculate the E°’ values and analyse the pH dependence of E°’. The electrochemical data were provided which will be useful for further electrochemical investigations regarding proteins bearing disulfide bridge(s) or cysteines prone to oxidation.
2020
- Hermetia illucens (L.) larvae as chicken manure management tool for circular economy
[Articolo su rivista]
Bortolini, Sara; Macavei, Laura Ioana; Saadoun, Jasmine Hadj; Foca, Giorgia; Ulrici, Alessandro; Bernini, Fabrizio; Malferrari, Daniele; Setti, Leonardo; Ronga, Domenico; Maistrello, Lara
abstract
The increased request for poultry meat and eggs of a rising human population requires more efficient and cleaner methods to manage increasing quantities of chicken manure. The black soldier fly Hermetia illucens is known as an efficient bio-converter of organic waste in proteins and fats, with the advantage that the larval frass is supposed to have compost-like properties. In the view to identify the operating conditions for the sustainable management and valorization of livestock waste at a pre-industrial scale, this study is aimed at: i) optimizing the growth of H. illucens on a mixture of chicken manure, chabazite and water; ii) assessing the soil amendment properties of the larval frass obtained from the optimized mixture. Preliminary trials allowed defining the basic rearing conditions in terms of temperature and substrate components. A mixture design based on a special cubic model allowed identifying the best mixture for H. illucens larvae growth, which consists in 34.5% chicken manure, 58.3% water and 7.2% coarse chabazite. This mix led to about 86% of alive prepupae weighting 90 mg on average, and to a reduction of the initial substrate amount by more than 75%. The larval frass obtained from this mixture showed soil improver properties, suggesting its use to supply the common peat based growing media for potted baby-leaf lettuce production. Overall, H. illucens larvae have proved to be a useful tool to favor a more sustainable management of chicken manure by strongly reducing its amount and closing its recovery cycle obtaining high value products for agricultural purposes.
2020
- Interlayer-confined Cu(II) complex as an efficient and long-lasting catalyst for oxidation of H2s on montmorillonite
[Articolo su rivista]
Castellini, E.; Bernini, F.; Sebastianelli, L.; Sainz-Diaz, C. I.; Serrano, A.; Castro, G. R.; Malferrari, D.; Brigatti, M. F.; Borsari, M.
abstract
Removal of highly toxic H2S for pollution control and operational safety is a pressing need. For this purpose, a montmorillonite intercalated with Cu(II)-phenanthroline complex [Cu[(Phen)(H2O)2]2+ (Mt-CuPhen) was prepared to capture gaseous H2S under mild conditions. This hybrid material was simple to obtain and demonstrated an outstanding ability to entrap H2S at room temperature, retaining high efficiency for a very long time (up to 36.8 g of S/100 g Mt-CuPhen after 3 months of exposure). Sorbent and H2S uptake were investigated by elemental analysis, X-ray powder diffraction measurements, diffuse reflectance (DR) UV–Vis and infrared spectroscopy, thermal analysis and evolved gas mass spectrometry, scanning electron microscopy equipped with energy-dispersive X-ray spectrometer, and X-ray absorption spectroscopy. The H2S capture was studied over time and a mechanism of action was proposed. The entrapping involves a catalytic mechanism in which [Cu[(Phen)(H2O)2]2+ acts as catalyst for H2S oxidation to S0 by atmospheric oxygen. The low cost and the long-lasting performance for H2S removal render Mt-CuPhen an extremely appealing trap for H2S removal and a promising material for many technological applications.
2020
- Mineralogy and crystallization patterns in conodont bioapatite from first occurrence (Cambrian) to extinction (end-Triassic)
[Articolo su rivista]
Medici, Luca; Malferrari, Daniele; Savioli, Martina; Ferretti, Annalisa
abstract
Bioapatite represents an important acquisition in the evolution of life, both in the seas and on land. Vertebrates applied calcium-phosphate biominerals to grow their skeletal support and to shape their teeth, while some invertebrates sheltered their soft parts within apatite shells. Conodonts were the first among vertebrates to experiment with skeletal biomineralization of tooth-like elements in their feeding apparatus. Spanning a time record of over 300 million years, they offer a unique tool to test possible variation in bioapatite structure from the experimentation of a very primitive biomineralization type to a more evolute pattern just before going extinct. X-ray microdiffraction carried out through an X-ray micro-diffractometer, integrated with environmental scanning electron microscopy coupled with chemical microanalyses (ESEM-EDX), has been applied in this study to investigate conodont element crystal structure throughout the entire stratigraphic range of these organisms. In particular, bioapatite crystallographic cell parameters have been calculated for about one hundred conodont elements ranging from the late Cambrian to the Late Triassic. Resulting data clearly indicate two distinct distribution plots of cell parameters for paraconodonts and euconodonts. In contrast, age, taxonomy, geographic provenance and CAI do not affect the dimension of the bioapatite crystal cells. Conodont bioapatite crystallographic cell parameters have been compared with cell parameters resulting from phosphatic/phosphatized material (ostracodes, brachiopods, bryozoans, and fish teeth) present in the same residues producing conodonts. Resulting values of the cell parameters are, in general, mainly correlated with the type of organisms even if, for some of them, a correlation also with age cannot be completely ruled out. According to our data, primary bioapatite appears to imprint a key signature on fossil crystal-chemistry (crystal structure and major chemical element contents), while the contribution of fossilization and diagenetic processes seems less relevant.
2020
- Phosphorylated cofilin-2 is more prone to oxidative modifications on Cys39 and favors amyloid fibril formation
[Articolo su rivista]
Pignataro, M.; Di Rocco, G.; Lancellotti, L.; Bernini, F.; Subramanian, K.; Castellini, E.; Bortolotti, C. A.; Malferrari, D.; Moro, D.; Valdre, G.; Borsari, M.; Monte, F. D.
abstract
Cofilins are small protein of the actin depolymerizing family. Actin polymerization/depolymerization is central to a number of critical cellular physiological tasks making cofilin a key protein for several physiological functions of the cell. Cofilin activity is mainly regulated by phosphorylation on serine residue 3 making this post-translational modification key to the regulation of myofilament integrity. In fact, in this form, the protein segregates in myocardial aggregates in human idiopathic dilated cardiomyopathy. Since myofilament network is an early target of oxidative stress we investigated the molecular changes induced by oxidation on cofilin isoforms and their interplay with the protein phosphorylation state to get insight on whether/how those changes may predispose to early protein aggregation. Using different and complementary approaches we characterized the aggregation properties of cofilin-2 and its phosphomimetic variant (S3D) in response to oxidative stress in silico, in vitro and on isolated cardiomyocytes. We found that the phosphorylated (inactive) form of cofilin-2 is mechanistically linked to the formation of an extended network of fibrillar structures induced by oxidative stress via the formation of a disulfide bond between Cys39 and Cys80. Such phosphorylation-dependent effect is likely controlled by changes in the hydrogen bonding network involving Cys39. We found that the sulfide ion inhibits the formation of such structures. This might represent the mechanism for the protective effect of the therapeutic agent Na2S on ischemic injury.
2020
- Recycling of thermally treated cement-asbestos for the production of porcelain stoneware slabs
[Articolo su rivista]
Ligabue, M. L.; Gualtieri, A. F.; Lassinantti Gualtieri, M.; Malferrari, D.; Lusvardi, G.
abstract
The directives of the European Commission Environment on the management of hazardous asbestos-containing materials (ACM) are pointing towards treatment and recycling other than disposal in landfills. KRY·AS is a secondary raw material obtained by the thermal transformation of cement-asbestos (CA) and can be inserted in the production line of e.g. concrete, clay bricks, ceramics, and plastic materials. This being a possible future solution to the huge “CA-emergency” in Italy, additional recycling options are sought. In this work, KRY·AS was used for the production of glass-ceramic frits destined for the manufacturing of porcelain stoneware slabs. Two novel frits were obtained by vitrifying KRY·AS together with minor amounts of natural raw materials as well as glass waste. The resulting frits were added in a ceramic body formulation (0, 1, 3, 5 wt.%). Phase composition, microstructure and technological properties of fired samples were evaluated and the results were compared to those obtained when using a standard commercial frit. According to water absorption tests, the novel products can be classified as BIa-type. Comparable or even improved technological properties were found between the standard body and the frit-bearing ones. More precisely, the addition of 5 wt.% of the novel frits led to better stain resistance as well as higher productivity due to reduction of the linear firing shrinkage. Improved mechanical strength (ca. 75 MPa compared to ca 60 MPa for the standard) was also obtained. The novel recycling route of KRY·AS supports a conclusive solution for the management of hazardous CA in Italy.
2020
- The Oligocene-Miocene volcanism in the Apennine: discovery and characterization of baryte and phillipsite-Ba rich bed in the lower part of the Ranzano Formation (Reggio Emilia, Italy)
[Articolo su rivista]
Malferrari, D.; Gualtieri, A.; Panini, F.; Fioroni, C.
abstract
This work reports the biostratigraphic assessment and the
chemical and mineralogical characterization of a zeolitized and
barium-rich volcanic pyroclastic bed outcropping in the lower Secchia
Valley (Northern Apennines, Italy), very close to the boundary between
the Ranzano and the Monte Piano Formations. To our knowledge, it
is the older so far documented in the Emilian Epiligurian Succession
as, through nannofossil biostratigraphy, we have documented an early
Oligocene age (Rupelian CNO1 nannofossil zone) for the enclosing
sediments. The chemical and mineralogical composition, the latter
obtained through a multi-analytical approach combining X-ray powder
diffraction (Rietveld-RIR method) with thermal analyses coupled
with evolved gas mass spectrometry, revealed large amounts of Barich phillipsite, baryte, volcanic glass and subordinate quantities of
sanidine and plagioclase; on the other hand, phlogopite, idiomorphic
plagioclase and femic minerals, frequently found in younger volcanic
layers of the Ranzano Formation, here are absent. The quantitative
mineralogical assessment together with mineral associations suggest
that diagenesis did not play a relevant role in the crystallization of
phillipsite, but its role cannot be neglected for the crystallization of
baryte. Hypothesis on the genesis and transformation of the original
material and on the possible correlation with the coeval calc-alkaline
magmatic sources in the circum-Mediterranean area were considered,
but no definitive conclusion has been reached.
2020
- Tuning of halobenzenes uptake in montmorillonite from gas phase through a functionalization process involving Cu(II)-phenanthroline and heptanethiol
[Articolo su rivista]
Castellini, Elena; Malferrari, Daniele; Bernini, Fabrizio; Bighi, Beatrice; Mucci, Adele; Sainz Diaz, Ignacio Claro; Serrano, Aida; Castro, German R.; Brigatti, Maria Franca; Borsari, Marco
abstract
In this paper, montmorillonite functionalized with a Cu(II)-phenanthroline complex (Mt-CuPhen) and then exposed to heptanethiol vapors (Mt-CuPhen-HPT) was tested for the capture of halobenzenes in gas phase. The treatment of Mt-CuPhen with heptanethiol vapors produced important compositional changes involving Cu(II) reduction, oxidation of thiol to disulfide and dehydration of the mineral interlayer space.
Entrapping experiments were carried out on fluorobenzene, chlorobenzene and bromobenzene at 25 and 45°C. The hybrid material proved to be very efficient for all halobenzenes and especially for fluorobenzene. Observed performances are slightly affected by temperature. Halobenzene desorption occurred even at 100°C, a temperature quite lower than that required for decomposition of Mt-CuPhen-HPT. The Mt-CuPhen-HPT hybrid material, therefore, can be reused several times and requires low energy costs for regeneration. An alternative regeneration procedure based on disulfide removal has been proposed as well.
Mt-CuPhen-HPT was extensively characterized before and after halobenzenes immobilization through elemental analysis, UV-Vis measurements, thermogravimetric analyses, FTIR, NMR and X-ray absorption spectroscopies.
2019
- Characterisation of fibrous ferrierite in the rhyolitic tuffs at Lovelock, Nevada, USA
[Articolo su rivista]
Zoboli, A.; Di Giuseppe, D.; Baraldi, C.; Gamberini, M. C.; Malferrari, D.; Urso, G.; Lassinantti Gualtieri, M.; Bailey, M.; Gualtieri, A. F.
abstract
Ferrierite is the name for a series of zeolite-group of minerals which includes three species with the same ferrierite framework (FER) crystal structure but different extra-framework cations. Recent studies have shown that ferrierite can exhibit a fibrous-asbestiform crystal habit and may possess the same properties as carcinogenic fibrous erionite. Characterisation of the ferrierite in and around a mine location will be helpful in assessing the potential for toxic outcomes of exposure in the mine and any local population.The zeolite-rich tuff deposit of Lovelock, Nevada, USA is the largest occurrence of diagenetic ferrierite-Mg. A previous survey reported that ferrierite hosted in these rocks displays a fibrous morphology. However, these observations concerned a limited number of samples and until now there has been little evidence of widespread occurrence of fibrous ferrierite in the Lovelock deposit.The main goal of this study was to perform a mineralogical and morphometric characterisation of the tuff deposit at Lovelock and evaluate the distribution of fibrous ferrierite in the outcrop. For this purpose, a multi-analytical approach including powder X-ray diffraction, scanning and transmission microscopies, micro-Raman spectroscopy, thermal analyses, and surface-area determination was applied.The results prove fibrous ferrierite is widespread and intermixed with mordenite and orthoclase, although there are variations in the spatial distribution in the bedrock. The crystal habit of the ferrierite ranges from prismatic to asbestiform (elongated, thin and slightly flexible) and fibres are aggregated in bundles. According to the WHO counting criteria, most of the ferrierite fibres can be classified as breathable. While waiting for confirmatory in vitro and in vivo tests to assess the actual toxicity/pathogenicity potential of this mineral fibre, it is recommended to adopt a precautionary approach for mining operations in this area to reduce the risk of exposure.
2019
- How Much Can We Trust Major Element Quantification in Bioapatite Investigation?
[Articolo su rivista]
Malferrari, D.; Ferretti, A.; Mascia, M. T.; Savioli, M.; Medici, L.
abstract
Bioapatite is probably the key factor in the unreplicated success of vertebrates. Chemical data on bioapatite composition can be achieved on a solid sample by using different analytical tools such as spectroscopic and spectrometric methods. As analytical outputs can be affected by the physical-chemical characteristics of the sample matrix, an internal standard is usually required to correct and validate the results. Bioapatite lattice can accommodate iso- and heterovalent substitutions during life or diagenesis varying its chemical composition through (geological) time. If on the one hand, this makes bioapatite a unique archive of physical and chemical information for both the living cycle and the events occurring after death, on the other, it excludes the identification of a sole internal standard. Here, we propose a method to measure major element concentration with specific care for P, Ca, Mg, Na, K, Si, Al, and Fe, which are the main substituent atoms in bioapatite, through homemade matrix-matched external calibration standards for laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). We tested the method on living and fossil shark teeth, critically comparing the results obtained using other analytical techniques and certified external standards. We demonstrated that matrix-matched calibration in LA-ICPMS is mandatory for obtaining a reliable chemical characterization even if factors such as matrix aggregation variability, diverse presence of volatile compounds, the fossilization footprint, and the instrumental variability can represent further variability parameters.
2019
- Quantitative phase analysis using the Rietveld method: Towards a procedure for checking the reliability and quality of the results
[Articolo su rivista]
Gualtieri, A.; Gatta, G. D.; Arletti, R.; Artioli, G.; Ballirano, P.; Cruciani, G.; Guagliardi, A.; Malferrari, D.; Masciocchi, N.; Scardi, P.
abstract
The quantitative phase analysis using the Rietveld method is one of the most used analytical protocols for the characterization of several types of natural and synthetic materials, and it can be performed both on fully crystalline multiphase systems and on materials containing even an amorphous fraction. Therefore, there are several applications of this method (e.g., to natural raw materials, traditional ceramics, bricks, glass-ceramics, cementitious binders, etc.). More recently, the application of the Rietveld method has disseminated also in the chemical, pharmaceutical, and other high added-value industrial areas, where it is exploited in the operational planning, formulation analysis, and in patent protection. Nowadays, in consequence of this diffusion, several academic and private laboratories provide phase quantitative analysis using the Rietveld method as customers service, but an accreditation procedure is still pending and lacks a protocol for checking the authenticity and quality of the analytical reports. In this letter, we focus on the principal elements that an analytical report of quantitative phase analysis, based on the Rietveld method, should contain, as well as some best-practice guidelines for sample preparation and data collection procedure.
2019
- Structural properties of adsorbent phyllosilicates rule the entrapping ability of intercalated iron-phenanthroline complex towards thiols
[Articolo su rivista]
Castellini, E.; Malferrari, D.; Bernini, F.; Mucci, A.; Borsari, M.; Brigatti, M. F.
abstract
The interaction of volatile organic sulfur derivatives, such as 1-heptanethiol (C7H16S), with clay minerals treated with a μ-oxo Fe3+-phenanthroline 1:1 complex results strongly affected by crystal chemical properties of pristine mineral phases. In particular, two sepiolite clays with different structural features demonstrated significantly different ability to immobilize the Fe3+-phenanthroline complex at two pH values (pH = 5.4 and pH = 2.3). The most effective binding was obtained with sepiolite with higher structural disorder at pH 5.4. Accordingly, the resulting hybrid material showed also the greatest efficiency in removal of thiol in gas phase. A direct correlation can be established between the adsorption of the Fe3+-phenanthroline complex and the gas binding process at room temperature. In fact, 1-heptanethiol entrapping occurs via redox reactions between Fe3+ and a first thiol molecule to give the reduced Fe2+-phenanthroline complex and disulfide, followed by the binding of further thiols to the reduced metal centre. The extremely high amount of thiol immobilized by the hybrid material also suggests the co-presence of a catalytic mechanism that guarantees the reoxidation of Fe+2 to Fe+3 and the restoration of redox reactions with thiol. Investigation and conclusions were supported by the several experimental techniques: elemental analysis, X-ray powder diffraction analyses, UV–Vis measurements, FT-IR and NMR spectroscopies, thermogravimetric analyses.
2019
- Sulfur bearing and aromatic compound trapping by layered silicates: a great start for innovative technological applications
[Abstract in Atti di Convegno]
Malferrari, D.; Bernini, F.; Bighi, B.; Borsari, M.; Brigatti, M. F.; Castellini, E.; Mucci, A.; Sebastianelli, L.
abstract
2019
- Trapping at the Solid-Gas Interface: Selective Adsorption of Naphthalene by Montmorillonite Intercalated with a Fe(III)-Phenanthroline Complex
[Articolo su rivista]
Castellini, E.; Malferrari, D.; Bernini, F.; Sainz Diaz, C. I.; Mucci, A.; Sola, M.; Brigatti, M. F.; Borsari, M.
abstract
In this study, stable hybrid materials (Mt-Fe(III)Phen), made by the μ-oxo Fe(III)-phenanthroline complex [(OH 2 ) 3 (Phen)FeOFe(Phen)(OH 2 ) 3 ] 4+ (Fe(III)Phen) intercalated in different amounts into montmorillonite (Mt), were used as a trap for immobilizing gaseous benzene and naphthalene and their mono chloro-derivatives at 25 and 50 °C. The entrapping process was studied through elemental analysis, magic angle spinning NMR spectroscopy, thermal analysis, and evolved gas mass spectrometry. Naphthalene and 1-chloronaphthalene were found to be immobilized in large amount at both temperatures. Molecular modeling allowed designing of the structure of the interlayer in the presence of the immobilized aromatic molecules. Adsorption is affected by the amount of the Fe complex hosted in the interlayer of the entrapping hybrid materials. On the contrary, under the same conditions, benzene and chlorobenzene were not adsorbed. Thermal desorption of naphthalenes was obtained under mild conditions, and immobilization was found to be reversible at least for 20 adsorption/desorption cycles.
2018
- Abiotic formation of condensed carbonaceous matter in the hydrating oceanic crust
[Articolo su rivista]
Sforna, Marie Catherine; Brunelli, Daniele; Pisapia, Céline; Pasini, Valerio; Malferrari, Daniele; Ménez, Bénédicte
abstract
Thermodynamic modeling has recently suggested that condensed carbonaceous matter should be the dominant product of abiotic organic synthesis during serpentinization, although it has not yet been described in natural serpentinites. Here we report evidence for three distinct types of abiotic condensed carbonaceous matter in paragenetic equilibrium with low-temperature mineralogical assemblages hosted by magma-impregnated, mantle-derived, serpentinites of the Ligurian Tethyan ophiolite. The first type coats hydroandraditic garnets in bastitized pyroxenes and bears mainly aliphatic chains. The second type forms small aggregates (~2 µm) associated with the alteration rims of spinel and plagioclase. The third type appears as large aggregates (~100–200 µm), bearing aromatic carbon and short aliphatic chains associated with saponite and hematite assemblage after plagioclase. These assemblages result from successive alteration at decreasing temperature and increasing oxygen fugacity. They affect a hybrid mafic-ultramafic paragenesis commonly occurring in the lower oceanic crust, pointing to ubiquity of the highlighted process during serpentinization.
2018
- Chemical trapping of gaseous H2S at high and low partial pressures by an iron complex immobilized inside the montmorillonite interlayer
[Articolo su rivista]
Malferrari, Daniele; Castellini, Elena; Bernini, Fabrizio; Serrano Rubio, Aida; Rafael Castro, German; Ignacio Sainz-Díaz, Claro; Caleffi, Matteo; Brigatti, Maria Franca; Borsari, Marco
abstract
A stable hybrid material (Mt-Fe(III)Phen) formed by intercalation of the μ-oxo Fe(III)-phenanthroline complex
[(OH2)3(Phen)FeOFe(Phen)(OH2)3]4+ (Fe(III)Phen) in montmorillonite (Mt) is able to immobilize H2S in gaseous
phase with high efficiency even at extremely low pressures. DR UV–vis and I.R. spectroscopies, elemental analysis,
X-ray powder diffraction, thermal analysis coupled with evolved gas mass spectrometry, and X-ray absorption
spectroscopy show that the material has high adsorption capacity, performs fast H2S trapping and is long-lasting.
Moreover, even extremely low levels of H2S can be removed easily and quickly from gaseous phase using a suitable
amount of the trapping material. The immobilization mechanism likely involves a redox reaction between
iron (III) and one S2− ion, followed by the binding of a second S2− ion to the metal centre. The process takes
place at room temperature, is reversible for several cycles, and does not require pre-treatment of neither gaseous
H2S nor the adsorbent material. Therefore, this modified montmorillonite is a promising material to get rid of
H2S in processes of environmental interest and to obtain gaseous (and gasifiable) high quality hydrocarbons in
fuels refineries.
2018
- Experimental and Theoretical Investigation of Intercalation and Molecular Structure of Organo-Iron Complexes in Montmorillonite
[Articolo su rivista]
Sainz-Díaz, C. I.; Bernini, F.; Castellini, E.; Malferrari, D.; Borsari, M.; Mucci, A.; Brigatti, M. F.
abstract
The intercalation of the μ-oxo Fe(III)-phenanthroline 1:1 complex [(OH2)3(Phen)FeOFe(Phen)(OH2)3]+4 inside montmorillonite yielded a nanostructured material with strong and selective entrapping ability toward thiol molecules and hydrogen sulfide. In this work, experiments and computational molecular modeling by means of quantum mechanical calculations has been applied to study the molecular structure and interactions between this complex and the interlayer of montmorillonite. This approach allowed the identification of the geometrical disposition of the complexes inside the interlayer, the characterization of the hydration and coordination water molecules, and the explanation of the physico-chemical properties of these functionalized materials. The antiferromagnetic spin configuration of the Fe(III) ions results in the most stable state. Two conformers of the complex have been considered, having the phenanthroline rings in twisted or in parallel planes, respectively, and the transition of one conformer into the other has been explored by molecular dynamics simulations. The conformer with phenanthroline rings in parallel planes is found to be the favored species for intercalation in montmorillonite. Both experimental nuclear magnetic resonance analysis and adsorption isotherms are consistent with the modeling results. Different complex amount, equal and double of the cation exchange capacity (CEC) of montmorillonite, and hydration states inside the interlayer have been investigated reproducing faithfully the experimental d(001) spacing of the montmorillonite in the different conditions. The complex molecules intercalated over the CEC of montmorillonite adopt a disposition of the phenanthroline rings perpendicular to that of the complex already introduced by cation exchange.
2018
- HOW DID VERTEBRATES SHARPEN THEIR TEETH? A NEW PERSPECTIVE IN BIOAPATITE ANALYSIS
[Capitolo/Saggio]
Savioli, Martina; Ferretti, Annalisa; Medici, Luca; Malferrari, Daniele
abstract
HOW DID VERTEBRATES SHARPEN THEIR TEETH? A NEW
PERSPECTIVE IN BIOAPATITE ANALYSIS
2018
- Leaching behaviour of a sandy soil amended with natural and NH4+and K+saturated clinoptilolite and chabazite
[Articolo su rivista]
Eslami, Mahboubeh; Khorassani, Reza; Coltorti, Massimo; Malferrari, Daniele; Faccini, Barbara; Ferretti, Giacomo; DI GIUSEPPE, Dario; Fotovat, Amir; Halajnia, Akram
abstract
Using saturated or enriched zeolites as slow release fertilizers (SRFs) is considered as an environmental-friendly strategy to enhance use of macronutrients in sandy soils. In this paper, two natural zeolites, clinoptilolite (CLI) and chabazite (CHA) were used as mineral precursors to prepare NH4+/K+saturated clinoptilolite (NH4+/K+-CLI) and chabazite (NH4+/K+-CHA) as zeolitic nutrient sources (ZNSs). Comparison between the nutrient retention capabilities of these ZNSs was one of the main objectives of this study. The NH4+/K+-CLI and NH4+/K+-CHA were prepared by soaking the zeolites in NH4Cl and KCl solutions, respectively. Leaching tests were performed on a sandy soil amended with chemical fertilizers (CFs), NH4+/K+-CLI and NH4+/K+-CHA to evaluate the leaching properties of them. The results indicated that approximately 84% and 88% of the NH4+and K+of soils fertilized with CFs were lost during the experiment, respectively. While, the NH4+and K+losses from soils amended with NH4+/K+-CLI and NH4+/K+-CHA were 29%, 23%, and 14%, 24%, respectively. Despite of drastic changes in leaching behavior of CFs, nutrient losses from ZNSs were more uniform during the experiments. No significant difference was found between the two studied zeolites on reduction of K+loss. However, CHA was more effective in preventing NH4+loss during leaching.
2018
- Organo-modified bentonite for gentamicin topical application: interlayer structure and in vivo skin permeation
[Articolo su rivista]
Iannuccelli, Valentina; Maretti, Eleonora; Bellini, Alessia; Malferrari, Daniele; Ori, Guido; Montorsi, Monia; Bondi, Moreno; Truzzi, Eleonora; Leo, Eliana Grazia
abstract
Recent biomedical applications of clay materials have included organically modified clays or clay minerals with the purpose of modifying and improving drug biological activity. The present research aims to explore the potential benefits provided by a raw bentonite (Bt) modified by gentamicin (GM) adsorbed within montmorillonite interlayers in the management of cutaneous infectious diseases. Information arisen from controlled X-ray powder diffraction, thermogravimetry coupled with evolved gas mass spectrometry, and molecular dynamics simulations pointed out GM monolayer arrangement within montmorillonite framework without producing substantial effects on the layer periodicity. Concerning skin biomedical application, unlike the pure antibiotic permeating along the trans-follicular pathway across stratum corneum, the organo-modified Bt/GM would favor the trans-epidermal route along inter-cluster corneocyte region, as in vivo skin penetration studies by means of tape stripping test indicated. Based on the results obtained, GM intercalation could represent a potential advantageous approach allowing a long-term Bt/GM reservoir for sustained antibacterial activity.
2018
- Valorisation of chicken manure using insects: Hermetia illucens in the VALORIBIO Project
[Abstract in Atti di Convegno]
Bortolini, S.; Macavei, L. I.; Foca, G.; Ulrici, A.; Bernini, F.; Malferrari, D.; Maistrello, L.
abstract
Over the last decades, the need to manage organic waste in a more efficient way and the need to find new sources of energy have opened new horizons in the use of insects for various purposes (e.g. food, feed, biodiesel).
The ValoriBio project focuses on the valorisation of chicken manure through the use of Hermetia illucens (Diptera, Stratiomyidae), for the production of high quality compost and bioplastics for agricultural purposes.
This study is aimed at the optimisation of the growth parameters of H. illucens on a substrate formed by a mixture of chicken manure, zeolitic tuff (Ca-chabazite), soil improver obtained from pruning shears of urban green, and water. The addition of the Ca-chabazite aims to reduce unpleasant smells, trap the excess of ammonium, and contribute to the formation of a post-breeding substrate which can be used as high-quality compost. The parameters to be maximized were: percentage and maximum average weight of prepupae and percentage of emerged adult flies. Results of a first trial, based on a special cubic model of combined mixture design that tested different ranges of the substrates at 27 and 33°C, recommended the removal of the soil improver and the selection of 27°C as preferred rearing temperature.
A second trial considered different ranges of chicken manure, Ca-chabazite (at two different particle sizes) and water. Results from this experiment allowed the definition of the optimal composition for the substrates to obtain the highest percentage of prepupae (71-74%) and the highest average prepupae weight (0.069-0.072g), and were therefore used to plan the validation test, where chicken manure ranged between 34.5 and 45.0%, Ca-chabazite (larger particle size) between 5.0 and 7.2%, and water between 50.0 and 58.3%. These results are the basis to develop an optimized rearing cycle of H. illucens in an automatized pilot plant for organic waste conversion.
2017
- Baseline studies of The Clay Minerals Society Source Clay montmorillonite STx-1b
[Articolo su rivista]
Castellini, Elena; Malferrari, Daniele; Bernini, Fabrizio; Brigatti, Maria Franca; Castro, German Rafael; Medici, Luca; Mucci, Adele; Borsari, Marco
abstract
For more than forty years, The Clay Minerals Society has dispensed a set of source clays which have enabled a large number of researchers to work on identical materials. Many of these source clays remained unchanged over the years but, conversely, other clays have gone out of stock and thus were replaced. This was the fate of montmorillonite STx-1a, which was replaced by STx-1b. Although STx-1a and STx-1b share many basic chemical and mineralogical features, some minor differences exist that can affect behavior. A baseline characterization of the source clay STx-1b, which was the objective of this study, was, therefore, necessary to provide researchers a tool useful not only for new investigation but also to compare new results obtained on STx-1b with literature data on STx-1a. This characterization was gained using traditional and advanced methods that include: 1) chemical composition (major and trace elements); 2) cation exchange capacity determination; 3) thermal analyses coupled with evolved gas mass spectrometry; 4) quantitative mineralogical characterization using powder X-ray diffraction and Rietveld-RIR (Reference Intensity Ratio) refinement; 5) X-ray absorption spectroscopy at the Fe K-edge; 6) diffuse reflectance ultraviolet-visible and infrared spectroscopies; 7) 29Si, 27Al, and 1H magic-angle spinning nuclear magnetic resonance measurements. According to this multi-analytical approach, the montmorillonite chemical formula is [4](Si7.753 Al0.247) [6](Al3.281 Mg0.558 Fe0.136 Ti0.024 Mn0.002) [12](Ca0.341 Na0.039 K0.061) O20 (OH)4.
2017
- Corrigendum: Pre-amyloid oligomers budding:a metastatic mechanism of proteotoxicity
[Articolo su rivista]
Bernini, F.; Malferrari, D.; Pignataro, M.; Bortolotti, C. A.; Di Rocco, G.; Lancellotti, L.; Kayed, R.; Borsari, M.; Del Monte, F.; Castellini, E.; Brigatti, M. F.
abstract
2017
- Crystal chemical characterization and computational modeling of a μ-oxo Fe(III) complex with 1,10-phenanthroline clarify its interaction and reactivity with montmorillonite
[Articolo su rivista]
Brigatti, Maria Franca; Díaz, Claro Ignacio Sainz; Borsari, Marco; Bernini, Fabrizio; Castellini, Elena; Malferrari, Daniele
abstract
This work provides a systematic study of the μ-oxo-di-fac-[triaqua-(1,10-phenanthroline-κ2N,N′)-iron(III)]bis(sulfate), [(OH2)3(phen)FeOFe(phen)(OH2)3] (SO4)2 (phen = phenanthroline). Crystal structure is determined by single-crystal X-ray diffraction data and refined to R = 0.039. The crystal structure is monoclinic (Z = 2), space group P21 with unit cell dimensions a = 8.5157(3), b = 17.6434(5), c = 9.9678(3) Å, β = 90.133(2)°, V = 1497.62(8) Å3. The triaqua(1,10-phenanthroline)iron(III) parts are linked through one oxo-bridge. Both Fe(III) cations show a distorted octahedral coordination. The single-crystal data are complemented by computational chemistry modeling at quantum mechanical level, X-ray powder diffraction at room and high temperature conditions and by thermal analysis. Molecular modeling suggests that the role of the crystallization water molecules is critical to establish the intermolecular interactions for the stability of the crystal structure.
2017
- Diagenesis does not invent anything new: Precise replication of conodont structures by secondary apatite
[Articolo su rivista]
Ferretti, Annalisa; Malferrari, Daniele; Medici, Luca; Savioli, Martina
abstract
Conodont elements are important archives of sea/pore water chemistry yet they often exhibit evidence of diagenetic mineral overgrowth which may be biasing measurents. We decided to investigate this phenomenon by characterising chemically and crystallographically, the original biomineral tissue and the diagenetic mineral nature of conodont elements from the Ordovician of Normandy. Diagenetic apatite crystals observed on the surface of conodont elements show distinctive large columnar, blocky or web-like microtextures. We demonstrate that these apatite neo-crystals exhibit the same chemical composition as the original fossil structure. X-ray microdiffraction has been applied herein for the first time to conodont structural investigation. Analyses of the entire conodont element surface of a variety of species have revealed the existence of a clear pattern of crystal preferred orientation. No significant difference in unit cell parameters was documented between the newly formed apatite crystals and those of the smooth conodont surfaces, thus it emerges from our research that diagenesis has strictly replicated the unit cell signature of the older crystals.
2017
- Effective and Selective Trapping of Volatile Organic Sulfur Derivatives by Montmorillonite Intercalated with a μ-oxo Fe(III)-Phenanthroline Complex
[Articolo su rivista]
Bernini, Fabrizio; Castellini, Elena; Malferrari, Daniele; Castro, German Rafael; Sainz Díaz, Claro Ignacio; Brigatti, Maria Franca; Borsari, Marco
abstract
The mu-oxo Fe(III) phenatithroline Complex [(OH2)(3)(Phen)FeOFe(Phen) (OH2)(3)](+4) intercalated in montmorillonite provides a stable hybrid material. In this study, the ability and efficiency of this material to immobilize thiols in gas phase, acting as a trap at the solid-gas interface, were investigated. Aliphatic thiols containing both hydrophilic and hydrophobic end groups were chosen to test the selectivity of this gas trap. DR-UV vis, IR, elemental analysis, thermal analysis and evolved gas mass spectrometry, X-ray powder diffraction, and X-ray absorption spectroscopy techniques were employed to characterize the hybrid material before and after thiol exposure and to provide information on the entrapping process. Thiol immobilization is very large, up to 21% w/w for heptanethiol. In addition, evidence was obtained that immobilization occurs through the formation of a covalent bond between the iron of the complex and the sulfur of the thiol. This provides an immobilization process characterized by a higher stability with respect to the method's based on physi-adsorption. Thiol immobilization resulted thermally reversible at least for 20 adsorption/desorption cycles. Unlike standard desulfurization processes like hydrotreating and catalytic oxidation which work at high temperatures and pressures, the present system is able to efficiently trap thiols at room temperature and pressure, thus saving energy. Furthermore,we found that the selectivity of thiol immobilization can be tuned acting on the amount of complex intercalated in montmorillonite. In particular, montmorillonite semisaturated with the complex captures both hydrophobic and hydrophilic thiols, while the saturated montmorillonite shows a strong selectivity toward the hydrophobic molecules.
2017
- Experimental and Molecular Dynamics Investigation Proves That Montmorillonite Traps the Biogenic Amines Histamine and Tyramine
[Articolo su rivista]
Malferrari, Daniele; Bernini, Fabrizio; Tavanti, Francesco; Tuccio, Luca; Pedone, Alfonso
abstract
Biogenic amines present in high concentrations in foods obtained through fermentation could have toxic effects and contribute to the arising of allergies. For this reason, their removal is of great importance. In this work, we used an experimental and computational approach to investigate the interaction between a calcium montmorillonite, a layered silicate very common in clays, and the two biogenic amines histamine and tyramine, obtaining deep insight into their binding modalities and structural organization. Calcium montmorillonite can exchange almost all its interlayer Ca2+with the protonated histamine and tyramine, thus reducing their concentration in water solution. The adopted multianalytical approach allowed classification of the interaction mechanism as an intercalation. Molecular dynamics simulations showed that the intercalated histamine and tyramine preferentially interact, through the protonated amino nitrogen, with tetrahedral aluminum bearing a net negative charge, whereas interactions with neutral tetrahedral silica is less favorable. We observed that most of histamine molecules bind in the center and above the 6T net of the silica sheet, but for electrostatic constraints they cannot occupy the center of two adjacent 6T nets as occurs for tyramine.
2017
- Mineralogical characterization of apatite biominerals: preliminary results
[Capitolo/Saggio]
Medici, Luca; Ferretti, Annalisa; Malferrari, Daniele; Cavalazzi, Barbara; Savioli, Martina
abstract
Bioapatite fossils are investigated and compared by the use of microdiffraction technique.
2017
- PRODUCT FOR DEFENDING AND FEEDING PLANTS AND RESPECTIVE PREPARATION METHOD AND USE
[Brevetto]
Malferrari, Daniele; Poppi, Stefano
abstract
A product for defending and feeding plants that comprises a co-formulant and an active principle, in which the co-formulant consists of a mixture of natural mineral substances chosen from a group comprising calcite, cristobalite, muscovite/illite, magnesium pyroxene, plagioclase, quartz, sanidine, zeolite chabasite, zeolite phillipsite, zeolite clinoptilolite, and the active principle comprises copper sulphate and copper hydroxide. A method for preparing the product for defending and feeding plants comprises the following steps: - preparing a water suspension containing, the co-formulant, copper sulphate and copper hydroxide; - agitation of the water suspension and simultaneous milling of the minerals that make up the co-formulant for a time variable between 24 and 36 hours until reaching granulometry of the solid substances in the water suspension that is not greater than 30 micron; - drying and simultaneous atomising of the product; chemical/physical rebalancing of the product to environmental conditions and subsequent packaging of the product.
2016
- Ammonium-charged zeolitite effects on crop growth and nutrient leaching: Greenhouse experiments on maize (Zea mays)
[Articolo su rivista]
Campisi, T.; Abbondanzi, F.; Faccini, B.; Di Giuseppe, D.; Malferrari, Daniele; Coltorti, M.; Laurora, A.; Passaglia, E.
abstract
Nitrate leaching and the resulting groundwater contamination from intensive crop production has become a major concern for long-term farmland efficiency and environmental sustainability in Italy. The aim of this study was to evaluate a water-saving NH4-charged zeolitite (produced by a new prototype) for minimizing NO3-leaching from soil and optimizing corn growth and yield. Forty-eight zeolitite:soil lysimeters in two trials were installed in a greenhouse to study the growth and yield characteristics of maize (Zea mays) as well as the nitrate concentration in leachate under different fertilizing conditions (i.e., standard, high or 70%, medium or 50% and low or 30% of conventional fertilization rate) and NH4-charged zeolitite (control, 0; dose-1, 50tha-1 and dose-2, 100tha-1) treatments. The results implicitly suggest that plants may have a better response if NH4-charged zeolitite is used with a limited amount of conventional fertilizer, allowing a reduction of nitrate concentration in drainage.
2016
- An alternative method of calculating cleavage energy: The effect of compositional domains in micas
[Articolo su rivista]
Brigatti, Maria Franca; Elmi, Chiara; Guggenheim, Stephen; Malferrari, Daniele; Poppi, Marco
abstract
Cell parameters and atomic coordinates for the true micas are varied to simulate layer deformation along the [001]* direction by an external force. The resulting (deformed) structures are then used to determine bonding forces and to calculate a maximum force component along the [001]*. Bonding forces are compared to experimental observations of bond lengths of the interlayer, octahedral, and tetrahedral sites. Calculated bonding forces are consistent with experimental observations that locate the cleavage plane along the interlayer. Because many studies have shown that the chemical composition of the cleavage surface often differs from the structure of the bulk, compositional variations were considered in determining cleavage energy. The chemical composition of the cleavage surface may produce a reduction in cleavage energy. This reduction in energy depends on various elements occurring in greater number at the cleavage surface than in the bulk. A reduction in cleavage energy occurs if there is a reduction in the interlayer site size, as measured by the area defined by the first-coordination basal oxygen atoms. In addition, a reduction in lateral cell dimensions and an increase in the bonding force between the basal oxygen atoms and the interlayer cation also results in a reduction in cleavage energy in the direction normal to the layer.
Joins considered are phlogopite–annite, tetra-ferriphlogopite–tetra-ferri-annite, polylithionite–
siderophyllite, muscovite–celadonite, and muscovite–paragonite. A lack of homogeneity in composition may produce preferential cleavage locations within the family of (001) planes. The cleavage energy appears to be greater for homogeneous synthetic micas compared to natural micas.
2016
- Crystals on the rocks. Apatite overgrowth on conodont elements from the Late Ordovician of Normandy, France
[Abstract in Atti di Convegno]
Ferretti, Annalisa; Malferrari, Daniele; Medici, Luca; Savioli, Martina
abstract
Apatite overgrowth patterns on Ordovician conodonts are here referred to metamorphism.
2016
- In situ high-temperature X-ray diffraction and spectroscopic study of fibroferrite, FeOH(SO4)·5H2O
[Articolo su rivista]
Ventruti, Gennaro; Ventura, Giancarlo Della; Corriero, Nicola; Malferrari, Daniele; Gualtieri, Alessandro; Susta, Umberto; Lacalamita, Maria; Schingaro, Emanuela
abstract
The thermal dehydration process of fibroferrite, FeOH(SO4)·5H2O, a secondary iron-bearing hydrous sulfate, was investigated by in situ high-temperature synchrotron X-ray powder diffraction (HT-XRPD), in situ high-temperature Fourier transform infrared spectroscopy (HT-FTIR) and thermal analysis (TGA-DTA) combined with evolved gas mass spectrometry. The data analysis allowed the determination of the stability fields and the reaction paths for this mineral as well as characterization of its high-temperature products. Five main endothermic peaks are observed in the DTA curve collected from room T up to 800 °C. Mass spectrometry of gases evolved during thermogravimetric analysis confirms that the first four mass loss steps are due to water emission, while the fifth is due to a dehydroxylation process; the final step is due to the decomposition of the remaining sulfate ion. The temperature behavior of the different phases occurring during the heating process was analyzed, and the induced structural changes are discussed. In particular, the crystal structure of a new phase, FeOH(SO4)·4H2O, appearing at about 80 °C due to release of one interstitial H2O molecule, was solved by ab initio real-space and reciprocal-space methods. This study contributes to further understanding of the dehydration mechanism and thermal stability of secondary sulfate minerals.
2016
- Overgrowth of apatite crystals on the surface of Late Ordovician conodonts from Normandy, northern France
[Abstract in Atti di Convegno]
Ferretti, Annalisa; Malferrari, Daniele; Medici, Luca; Savioli, Martina
abstract
Peculiar apatite overgrowth on Ordovician conodont elements are described.
2016
- Pre-amyloid oligomers budding:a metastatic mechanism of proteotoxicity
[Articolo su rivista]
Bernini, Fabrizio; Malferrari, Daniele; Pignataro, Marcello; Bortolotti, Carlo Augusto; DI ROCCO, Giulia; Lancellotti, Lidia; Brigatti, Maria Franca; Kayed, Rakez; Borsari, Marco; Del Monte, Federica; Castellini, Elena
abstract
The pathological hallmark of misfolded protein diseases and aging is the accumulation of proteotoxic aggregates. However, the mechanisms of proteotoxicity and the dynamic changes in fiber formation and dissemination remain unclear, preventing a cure. Here we adopted a reductionist approach and used atomic force microscopy to define the temporal and spatial changes of amyloid aggregates, their modes of dissemination and the biochemical changes that may influence their growth. We show that pre-amyloid oligomers (PAO) mature to form linear and circular protofibrils, and amyloid fibers, and those can break reforming PAO that can migrate invading neighbor structures. Simulating the effect of immunotherapy modifies the dynamics of PAO formation. Anti-fibers as well as anti-PAO antibodies fragment the amyloid fibers, however the fragmentation using anti-fibers antibodies favored the migration of PAO. In conclusion, we provide evidence for the mechanisms of misfolded protein maturation and propagation and the effects of interventions on the resolution and dissemination of amyloid pathology.
2016
- Prodotto per la nutrizione e la difesa di piante e relativi metodo di preparazione e uso
[Brevetto]
Malferrari, Daniele; Poppi, Stefano
abstract
La presente invenzione riguarda la formulazione di un prodotto a base di rame utilizzabile in ambito agricolo per la nutrizione e la difesa delle piante tramite applicazione del prodotto al terreno e sulle piante stesse, con particolare riferimento ai settori dell’arboricoltura, ad esempio in frutteti e vigneti e orticoltura specializzata. L’invenzione riguarda anche un metodo per la preparazione del suddetto prodotto a base di rame e le modalità di uso del prodotto.
2016
- Supercritical CO2 Confined in Palygorskite and Sepiolite Minerals: A Classical Molecular Dynamics Investigation
[Articolo su rivista]
MUNIZ MIRANDA, Francesco; Lodesani, Federica; Tavanti, Francesco; Presti, Davide; Malferrari, Daniele; Pedone, Alfonso
abstract
We have investigated the ability of two modular phyllosilicates (palygorskite and sepiolite) to store CO2 molecules inside their structural channels by means of classical molecular dynamics. Several models containing an increasing supercritical-CO2/H2O ratio into the phyllosilicate channels have been built and the structural and dynamic properties of carbon dioxide and water molecules investigated in detail. We found that both clay minerals can achieve this goal, with sepiolite being able to store more carbon dioxide molecules (and more stably) than palygorskite, due to the larger channels of the former. Interestingly, with the increase of CO2 molecules inside the minerals, the diffusivity of both water and carbon dioxide drastically decreases and carbon dioxide molecules tend to arrange themselves in an ordered pattern. (Figure Presented).
2016
- Zinc incorporation in the miliolid foraminifer Pseudotriloculina rotunda under laboratory conditions
[Articolo su rivista]
Nardelli, M. P.; Malferrari, Daniele; Ferretti, Annalisa; Bartolini, A.; Sabbatini, A.; Negri, A.
abstract
The incorporation rate of Zn into the calcareous tests of Pseudotriloculina rotunda was investigated in culture in order to evaluate the possibility of using Zn/Ca ratios as a pollution proxy. Foraminifera were incubated at zinc concentrations up to 10-fold higher than unpolluted seawater (sea + 10 mg Zn/L) during 70 days. New calcite was investigated under the Environmental Scanning Electron Microscope (ESEM), for potential alteration of test structure. Laser ablation-Inductively Coupled Plasma-Mass spectrometry (LA-ICP-MS) was used to quantify Zn contents. The analyses revealed that test structure is not visibly altered by the presence of zinc. However, significant Zn incorporation is detected by the LA-ICP-MS. The zinc partition coefficient, DZn, decreases at increasing Zn concentrations (from 4.03 ± 0.06 to 0.2 ± 0.01) and the zinc is incorporated into the calcite not necessarily linearly.
2015
- Ammonium-exchanged zeolitite preparation for agricultural uses: From laboratory tests to large-scale application in ZeoLIFE project prototype
[Articolo su rivista]
Faccini, Barbara; Di Giuseppe, Dario; Malferrari, Daniele; Coltorti, Massimo; Abbondanzi, Federica; Campisi, Tiziana; Laurora, Angela; Passaglia, Elio
abstract
Water nitrate pollution is one of the biggest environmental issues in all those Countries whose economy is largely based on agriculture. Limiting the nitrogen compound input in
the soil-water-air system requires the development of innovative and sustainable farming practices, allowing the reduction of fertilizer amounts but assuring good yields. This study
describes the optimization of the uptake of swine manure-derived ammonium by zeolitite, as one of the first result of ZeoLIFE project (“Water pollution reduction and water saving
using a natural zeolitite cycle”, LIFE+10 ENV/IT/000321). Natural Italian chabazite-bearing zeolitite has been mixed with swine manure at different zeolitite/manure ratios and operative
conditions, in a series of laboratory batch tests. The effective NH4 uptake has been measured with different methods, in order to validate the best criteria to reproduce the cation exchange reaction at large scale in a prototype, specifically conceived and built for the industrial production of NH4 charged zeolitite
2015
- Can facies act as a chronostratigraphical tool?
[Abstract in Atti di Convegno]
Ferretti, Annalisa; Cavalazzi, Barbara; Mclaughlin, Patrick I.; Barbieri, Roberto; Emsbo, Poul; Foucher, Frédéric; Malferrari, Daniele; Messori, Fabio; Westall, Frances
abstract
Results demonstrate that the Appalachian ironstones seem to reflect the same microbially-mediated iron mineralization already documented in the Carnic Alps.
2015
- I minerali e i metodi sperimentali per la determinazione delle nuove specie mineralogiche
[Capitolo/Saggio]
Malferrari, Daniele; Laurora, Angela
abstract
La parola minerale è utilizzata in diversi modi, spesso
impropriamente; per esempio in economia per minerale
si intende qualsiasi materiale estratto dalla Terra (incluso
carbone, petrolio, sabbia, ghiaia ecc.), mentre in mineralogia
la definizione è molto più restrittiva. Si definisce infatti
minerale un corpo naturale, per lo più solido e inorganico,
omogeneo dal punto di vista chimico, in quella condizione
stabile e anisotropa dello stato solido che è lo stato cristallino.
Il minerale è una sostanza che si forma naturalmente durante
processi geologici che hanno luogo sulla Terra o su corpi
extraterrestri e che conferiscono alla sostanza stessa ben
definite proprietà. La caratterizzazione di queste proprietà
diviene, quindi, un mezzo univoco per stabilire se una sostanza
di cui siamo venuti in possesso è o non è un minerale e se è
una specie mineralogica già nota o nuova.
Il presente lavoro, dopo una doverosa premessa sulla
definizione di minerale e sulle restrizioni a essa applicate, si
articola in una sintesi delle principali e più recenti procedure
analitiche necessarie per determinare sia quelle proprietà
fisiche e ottiche, sia quei parametri chimici cristallografici
che servono per definire univocamente una nuova specie
minerale.
2015
- Stepwise structuring of the adsorbed layer modulates the physico-chemical properties of hybrid materials from phyllosilicates interacting with the μ-oxo Fe+3-phenanthroline complex
[Articolo su rivista]
Bernini, Fabrizio; Castellini, Elena; Malferrari, Daniele; Borsari, Marco; Brigatti, Maria Franca
abstract
The -oxo Fe+3-phenanthroline 1:1 complex [(OH2)3(Phen)FeOFe(Phen)(OH2)3]+4 (hereafter Fe+3Phen) was successfully immobilized on montmorillonite (Mt) and kaolinite (Kt) minerals. Adsorption data on both minerals described an adsorption isotherm of VI type and were successfully fitted using two independent Frumkin isotherms. The interaction between the complex and the minerals is strong and yields two stable hybrid materials: Kt-Fe+3Phen and Mt-Fe+3Phen. DR UV-Vis, elemental analysis, TGA-MSEGA, temperature-controlled XRPD techniques were used to characterize the structural properties of the hybrid materials. These investigations showed that the Fe+3Phen adsorption occurs stepwise via the formation of a bilayer structure. The first layer is the result of a cation exchange process involving the negative charges of the mineral while the second one probably forms through stacking interaction and/or sulphate ions bridging. XRD diffraction measurements show that in Mt the second layer formation is accompanied by a super- structuring of the interlayer that changes the thermal and chemical properties of the composite material. In particular, interesting catalytic properties are observed in Mt-Fe+3Phen samples, but they are completely suppressed with the formation of the Fe+3Phen bilayer structure.
2015
- Trioctahedral Fe-rich micas: Relationships between magnetic behavior and crystal chemistry
[Articolo su rivista]
Brigatti, Maria Franca; Affronte, Marco; Elmi, Chiara; Malferrari, Daniele; Laurora, Angela
abstract
Six Fe-bearing mica samples with different Fe ordering, Fe2+/(Fe2++Fe3+) ratio, octahedral, and tetrahedral composition were studied. Four micas belong to the phlogopite-annite join (space group C2/m), two are Mg-rich annite and two are Fe-rich phlogopite, one is a tetra-ferriphlogopite (space group C2/m) and one is Li-rich siderophyllite (space group C2). Thus these samples had a different environment around the Fe cations and layer symmetry. These micas were characterized by chemical analyses, single-crystal X-ray diffraction, X-ray absorption spectroscopy, and magnetic measurements. In samples with Fe mostly in octahedral coordination, dominant magnetic interactions among Fe atoms are ferromagnetic, which reach a maximum at higher Fe2+/(Fe2++Fe3+) ratios. Samples with higher Fe2+/(Fe2++Fe3+) ratio are also characterized by higher values of the Curie-Weiss theta constant. Where Fe2+/(Fe2++Fe3+) ratios decrease, theta values also decrease. The Fe3+-rich phlogopite shows predominant Fe3+ in tetrahedral coordination and shows anti-ferromagnetic interactions with a negative value of the Curie-Weiss theta constant (i.e., theta = 25 K). Fe ordering in octahedral trans- and in one of the two cis-sites accounts for a greater theta value in Li-rich siderophyllite when compared to other samples showing similar octahedral Fe content. Our data suggest that Fe3+ cations and other non-ferromagnetic cations hinder long range magnetic ordering. This observation may produce for the different role of octahedral Fe magnetic interactions that can in principle develop along long Fe-rich octahedral chains, when compared to tetrahedral-octahedral interactions that are confined within the layer by the non-ferromagnetic cations of the interlayer. Spin glass behavior is indicated by the dependency of the temperature to produce maxima in the susceptibility curve. These maxima are related to the frequency of the applied AC magnetic field.
2014
- COLUMN LEACHING EXPERIMENTS ON AMMONIUM CHARGED ZEOLITITE
[Articolo su rivista]
Faccini, Barbara; Di Giuseppe, Dario; Colombani, Nicolò; Mastrocicco, Micol; Malferrari, Daniele; Coltorti, Massimo; Ferretti, Giacomo
abstract
Laboratory experiments were performed to evaluate the inorganic nitrogen leaching of NH4-charged zeolitite (chabazite-bearing). Two columns, filled with zeolitite enriched in ammonium by mixing with swine manure and NH4Cl solution, respectively, were flushed with synthetic rain water in saturated conditions. Ammonium content in the leachate solution of the first column was higher than that measured in the second column, but in both cases it represented less than 9% of the total exchangeable ammonium. A small amount of nitrate, deriving from the exchange method with manure, was also found in the first column. The quantity of ammonium remained in the zeolitite after leaching was determined via cation exchange with KCl. The results of this study suggest that the NH4-charged zeolitite is only little affected by nitrogen leaching by rainfall and could be safely used as soil conditioner for agricultural purposes.
2013
- IMA Commission on New Minerals, Nomenclature and Classification (CNMNC)
[Articolo su rivista]
Galli, Ermanno; Brigatti, Maria Franca; Malferrari, Daniele; Sauro, Francesco; De Waele, Jo
abstract
2012-056 ROSSIANTONITE
Al3(PO4)(SO4 )2(OH)2(H2O)14
Triclinic Space group: P1
a = 10.3410(5) b = 10.9600(5) c = 11.1446(5) Å
α = 86.985(2) β = 65.727(2) γ = 75.064(2)º
V = 1110.49(9) Å3 Z = 2
2013
- Impianto per trattare sostanze organiche e produrre un materiale fertilizzante
[Brevetto]
Laurora, Angela; Malferrari, Daniele; Passaglia, Elio
abstract
L’invenzione concerne un impianto per trattare sostanze organiche derivanti da rifiuti, scarti e/o decomposizioni – in particolare sostanze organiche contenenti azoto ammoniacale o ammonio, quali reflui zootecnici in forma liquida e/o digestati derivanti da processi di degradazione organica con microorganismi – così da produrre un materiale fertilizzante.
2013
- Open-field experimentation of an innovative and integrated zeolitite cycle: Project definition and material characterization
[Articolo su rivista]
Malferrari, Daniele; Laurora, Angela; Brigatti, Maria Franca; M., Coltorti; D. D., Giuseppe; B., Faccini; Passaglia, Elio; Vezzalini, Maria Giovanna
abstract
This study is a part of the European LIFE +2010 Project "ZeoLIFE - Water pollution reduction and water saving using a natural zeolitite cycle". It characterizes the application of Italian zeolite-rich pyroclastic rocks (zeolitites) as soil conditioner. Laboratory experiments will be tested on an experimental field in the Codigoro area, Ferrara district (North-East Italy). The samples investigated are chabazite- and phillipsite-rich and are all collected in quarries from Central Italy: (1) Grosseto area (Sorano and Sovana); (2) Viterbo area (Farnese, Grotte Santo Stefano, Corchiano, Nepi), and (3) Rome area (Riano). All samples are characterized by more than 30 % of zeolite content, together with volcanic glass, feldspars, pyroxenes, and micas. The quantitative mineralogical characterization of soil samples from Codigoro shows variable proportions of quartz, illite, plagioclase, K-feldspar, calcite, dolomite, chlorite, serpentine, kaolinite, gypsum together with an amorphous residual. Collected data confirm that conditioning of soils with selected zeolitite can be extremely promising for a well evident improvement of the soil quality, and contribute to define a standard approach which can surely find a general application well above the boundaries of the selected area for the field test. © 2013 Accademia Nazionale dei Lincei.
2013
- Rossiantonite, Al3(PO4)(SO4)2(OH)2(H2O)10•4H2O, a new hydrated aluminum phosphate-sulfate mineral from Chimanta massif, Venezuela: Description and crystal structure
[Articolo su rivista]
Galli, Ermanno; Brigatti, Maria Franca; Malferrari, Daniele; Sauro, F.; De Waele, J.
abstract
Rossiantonite, ideally Al3(PO4)(SO4) 2(OH)2(H2O)10·4H 2O, triclinic (space group P1̄), a = 10.3410(5), b = 10.9600(5), c = 11.1446(5) Å, α = 86.985(2), β = 65.727(2), γ = 75.064(2)°, V = 1110.5(1) Å3, Z = 2, is a new mineral from the Akopan-Dal Cin cave system in the Chimanta massif (Guyana Shield, Venezuela). The mineral occurs as small (≤0.15 mm) and transparent crystals in a white to slightly pink fine-grained sand, filling spaces between boulders of weathered quartz sandstone. Associated phases are gypsum, sanjuanite, rare alunite, quartz and micro-spherules of amorphous silica. Rossiantonite is colorless with a white streak and vitreous luster. The mineral is brittle with irregular to sub-conchoidal fracture and it shows a poorly developed cleavage. Rossiantonite is biaxial and not pleochroic, with mean refractive index of 1.504. The calculated density is 1.958 g/cm3. Electron microprobe analyses, with H2O measured by thermogravimetric analysis, provided the following empirical formula based on 28 O apfu: Al2.96Fe 0.03P1.01S2H30.02O 28. The five strongest lines in the X-ray powder diffraction pattern, expressed as d (Å), I, (hkl) are: 4.647, 100, (210); 9.12, 56, (100); 4.006, 53, (220); 8.02, 40, (110); 7.12, 33, (011). The crystal structure, refined using 3550 unique reflections to R = 0.0292, is built of PO4 and Al O6 polyhedral rings, creating complex chains parallel b by sharing the OH-OH edge belonging to the Al(3) polyhedron. Three symmetrically independent Al sites can be identified, namely: Al(1), Al(2), and Al(3). Tetrahedral sites, occupied by P, share all their apexes with AlO6 octahedra. Unshared octahedral apexes are occupied by water molecules. Four additional water molecules are placed in between the previously identified chains. Two oxygen tetrahedra, occupied by S atoms, are connected along the chains by means of weak hydrogen bonding. The rossiantonite structure shows similarities with minerals belonging to the sanjuanite-destinezite group.
2013
- Sodian muscovite-2M1: crystal chemistry and surface features
[Articolo su rivista]
Elmi, Chiara; Brigatti, Maria Franca; Guggenheim, S.; Pasquali, Luca; Montecchi, Monica; Malferrari, Daniele; Nannarone, Stefano
abstract
his study explores crystal chemical features of a sodian muscovite from Antarctica, both in the bulk of the mineral and at the uppermost surface layers. These features may support a deeper comprehension of processes affecting mineral surface and mineral physical properties. The muscovite under analysis is characterized by limited celadonite and paragonite substitutions and shows the following chemical formula: [XII](K1.73 Na0.27) [VI](Fe2+ 0.14 Al3+ 3.77 Mg 0.07 Ti0.01) [IV](Al1.91 Si6.09) O20 (F0.11 OH3.89). The sample is monoclinic, 2M1 polytype, with symmetry C2/c and unit cell parameters a = 5.1969(1), b = 9.0138(3), c = 20.0835(7) A, and β = 95.763(2)°. The two tetrahedral sites, T1 and T2, present similar distances (>T1.O< = 1.643A and >T2.O< = 1.647 A) and distortion parameter values, evidencing a disordered distribution of Si and Al at tetrahedral sites. The tetrahedral ring is significantly distorted (α = 11.2°) and the tetrahedral basal oxygen atom plane is remarkably wavy (δz = 0.224 A).Crystal chemical modifications at mineral surface were investigated by X-ray photoelectron spectroscopy. The interlayer cation K is eight-fold coordinated both in the bulk and at the surface, and its amount decreases at the surface. Sodium substitutes K and its coordination at the mineral surface is six. This evidence, together with a significant Na increase at the surface, is consistent with Na clustering close to the cleavage plane.
2013
- Sodium hexametaphosphate interaction with 2:1 clay minerals illite and montmorillonite
[Articolo su rivista]
Castellini, Elena; Berthold, C.; Malferrari, Daniele; Bernini, Fabrizio
abstract
The interaction of an efficient deflocculant, sodium hexametaphosphate (NaHMP), with illite and montmorillonite samples of different origins was investigated analyzing the HMP uptake (adsorption on mineral surface and/or intercalation inside the mineral interlayer) and the ion release mechanisms. HMP adsorption isotherms on a standard Na-saturated illite were determined at different temperatures providing the thermodynamic parameters of the process and the maximum adsorbed amount of the ion on this mineral. The data indicate that the adsorption process is hindered compared to that on kaolinite and are consistent with the hypothesis that HMP is chemiadsorbed on the aluminol edge sites, forming Al-O-P linkages. The effect of HMP on the natural illite and montmorillonite samples was analyzed using different techniques. Inductively coupled plasma optical emission spectroscopy (ICP-OES) measurements were used to detect the concentration of P, Si, Al, Ca, Mg and K in deflocculant solutions wetting the clay minerals in order to detail the immobilization, dissolution and exchange reactions associated to the deflocculant activity. Thermal analysis and XRD measurements were used as well to gain information on the properties of the HMP-treated clay mineral samples. Montmorillonite samples show a peculiar ability to immobilize HMP. Intercalation processes involving the formation of Ca2+/HMP complexes inside the mineral interlayer are proposed to explain this result and could be the reason of the well known decrease in the deflocculant efficiency of HMP in ceramic slurries rich in montmorillonite.
2013
- Use of zeolitites from
Central Italy in an integrated cycle aimed at water and chemical fertilizers saving (ZEOLIFE –
LIFE+10ENV/IT/000321)
[Abstract in Atti di Convegno]
Brigatti, Maria Franca; Laurora, Angela; Malferrari, Daniele; Passaglia, Elio; Vezzalini, Maria Giovanna
abstract
Introduction
The project “ZEOLIFE - Water pollution reduction and water saving using a natural zeolitite
cycle” has been conceived to test an innovative integrated zeolitite application having the aim to
reduce the NH4 content in livestock effluents and correct agricultural soils, with improvement of the
yield and economization of water for irrigation and fertilizers. This project leads to a reduction of
fresh and groundwater pollution and avoids excessive exploitation of the water resource. For further
details visit the website www.zeolife.it.
The first goal of the project was to carry out a chemical and physical, as well as
mineralogical characterization of several zeolitite samples, coming from different quarries located
in Central Italy, in order to select the most suitable raw material to be used throughout the entire
project.
Samples from the following seven localities were analyzed: Sorano (Gr), Sovana (Gr),
Farnese (Vt), Grotte Santo Stefano (Vt), Corchiano (Vt), Nepi (Vt), and Riano (Rm). All the
mentioned localities are the closest to the experimental field (Codigoro, Ferrara); in each quarry
non-marketable material, namely broken blocks or blocks with irregular shape and size, is available.
This material represents an already available reserve of zeolitic tuff that best fit the purposes of this
project.
Besides the technological properties of the raw material, the final choice also took into
account factors of environmental (e.g. carbon footprint) and economic (e.g, cost, full and immediate
availability) concern.
Experimental
In order to obtain representative samples from each examined locality, an appropriate
procedure was followed by picking out a total amount of 10 kg of raw material from different points
of the quarries. The collected material was accurately ground, and repeatedly quartered until
obtaining the needed sample amount.
Quantitative mineralogical analyses were carried out using the Rietveld method via the
General Structure Analysis System (GSAS) software package [1], combined with the Reference
Intensity Ratio (RIR) method for the determination of the amorphous phase [2].
Whole rock chemical analysis was carried out on pressed pellets via a wavelength-dispersive X-Ray
Fluorescence (XRF). Loss On Ignition (LOI) was determined by sample heating in a oven at
1100°C. CEC determination of exchanged Ca2+, Mg2+, Na+, and K+ cations was achieved via
Atomic Absorption Spectrometer (AAS) measurements. Apparent density was determined as the
ratio between the mass of ground sample which fills a measuring cup in loose conditions and the
volume of the cup. Water retention was determined using a modified Campbell’s methods [3].
Results and discussion
As demonstrated by plenty of experimental scientific works (e.g., [4] for a review),
chabazite is very effective not only in NH4 uptake from swine manure, but also in successive
controlled NH4 release in soils. Other zeolite species, such as phillipsite, have great potential for
244
NH4 adsorption and retention, but not the same capacity as chabazite in exchanging NH4 with
circulating solutions and plant root systems in soils.
A comparison between samples from studied quarries is reported in Fig. 1. As can be
observed the Sorano zeolitite shows the best features (e.g., high zeolite content and high CEC).
2012
- Channel Sediment Characterization and Evaluation of the Potential Impact of Iron-Rich Phases on the Use of Sediments in Brick Production
[Articolo su rivista]
Malferrari, Daniele; Laurora, Angela; Elmi, Chiara; Brigatti, Maria Franca; L., Medici; M. C., Zeqireja
abstract
Using data collected at both room temperature and higher temperatures, this study examined the mineralogy of, and iron coordination shell in, polluted sediments from drainage and irrigation channels. As a part of the study, mineralogical characteristics of iron phases of canal sediments were examined to determine if these sediments could be used in place of common clays for the production of bricks. While such use would reduce the impact of these wastes on the environment, an excess of iron in these sediments could affect some important features of bricks. Therefore, this study examined the oxidation state of iron as well as its structural location in the mineral matrix. X-ray powder diffraction, thermal analysis, and X-ray absorption spectroscopy were used to examine sediments and bricks manufactured from irrigation and drainage channels of the Po River region in northeast Italy. Results indicated that canal sediments can be used as row materials in clay brick production. In fact, the process temperature (950°C) that characterized brick production was similar to the temperature used for thermal treatment of polluted sediments in this study.
2012
- Magnetic behavior of trioctahedral micas with different octahedral Fe ordering
[Articolo su rivista]
Pini, Stefano; Brigatti, Maria Franca; Affronte, Marco; Malferrari, Daniele; A., Marcelli
abstract
This contribution is finalized at the discussion of the magnetic structure of two samples, belonging to phlogopite–annite [sample TK, chemical composition IV(Si2.76Al1.24) VI(Al0.64Mg0.72 Fe1.452+ Mn0.03Ti0.15) (K0.96Na0.05) O10.67 (OH)1.31 Cl0.02] and polylithionite–siderophyllite joints [sample PPB, chemical composition IV(Si3.14Al0.86)VI(Al0.75Mg0.01 Fe1.032+ Fe1.033+ Mn0.01Ti0.01Li1.09) (K0.99Na0.01) O10.00 (OH)0.65F1.35]. Samples differ for Fe ordering in octahedral sites, Fe2+/(Fe2+ + Fe3+) ratio, octahedral composition, defining a different environment around Fe cations, and layer symmetry. Spin-glass behavior was detected for both samples, as evidenced by the dependency of the temperature giving the peak in the susceptibility curve from the frequency of the applied alternating current magnetic field. The crystal chemical features are associated to the different temperature at which the maximum in magnetic susceptibility is observed: 6 K in TK, where Fe is disordered in all octahedral sites, and 8 K in PPB sample, showing a smaller and more regular coordination polyhedron for Fe, which is ordered in the trans-site and in one of the two cis-sites.
2011
- Characterization of gentamicin-bentonite complex
[Abstract in Atti di Convegno]
Bellini, Alessia; Malferrari, Daniele; Iannuccelli, Valentina; Coppi, Gilberto
abstract
Clays are common ingredients in pharmaceutical and cosmetic formulations, used as active substances (gastrointestinal protector, osmotic oral laxatives, antidiarrhoeaics, topical antibacterials and antinflammatories) and excipients in solid (tablet, capsules, powder), liquid (suspensions, emulsions) or semisolid (ointments, creams) forms.Among the mineral clays, bentonite (BNT) has high specific surface area and it exhibits good adsorption ability, cation exchange capacity, standout adhesive ability and drug-carrying capability.The present work aims to evaluate the intercalation of gentamicin molecules into BNT clay to obtain a drug delivery carrier for antibiotic treatment in a perspective to decrease gentamicin side effects and to improve systemic adsorption.More, clay antibacterial activity could produce a synergistic effect.BNT-gentamicin hybrid was characterized by X-ray diffraction, Fourier transformed infrared, ultraviolet-visible spectroscopy, thermal analysis, differential scanning calorimetry and simulations molecular dynamics modelling.Molecular modeling can suggest an interaction between bentonite and gentamicin molecules producing a monolayer in the montmorillonite (the main mineral composing bentonite) interlayer; adsorbed gentamicin is hydrated having, probably, water molecules located between the siloxane surface and gentamicin molecules with a resulting layer periodicity of 14.22 Å.The result obtained demonstrated the ability of gentamicin to be intercalated within the BNT structure.
2011
- Crystal chemistry and surface features of a 2M1 paragonitic muscovite
[Abstract in Rivista]
Elmi, Chiara; Brigatti, Maria Franca; Pasquali, Luca; Montecchi, Monica; Nannarone, Stefano; Malferrari, Daniele
abstract
The paragonitic muscovite considered [XII](K1.722 Na0.251 Ba0.010) [VI](Fe2+0.140 Al3+3.769 Cr3+0.003 Mg0.074 Ti0.012 Mn0.002) [IV](Al1.897 Si6.103) O20 (F0.109 OH3.891) came from Antarctica, it is monoclinic, 2M1 polytype, with symmetry C2/c and unit cell parameters a = 5.1969(1), b = 9.0138(3), c = 20.0835(7) (Å) and β = 95.763(2) (°).By using a multi-analytical approach this study describes the crystal chemical features of muscovite determined both in the bulk and on the uppermost surface layers. The bulk structure was refined by single crystal X-ray diffraction and the final refinement yielded the following agreement factor R = 0.0299. The two tetrahedral sites, T1 and T2, present similar distances (<T1-O> = 1.643 Å and <T2-O> = 1.647 Å) and distortion parameter values, thus evidencing a disordered distribution of [IV]Si and [IV]Al in tetrahedral sites. Tetrahedral ring is significantly distorted (α = 11.2°) and the tetrahedral basal oxygen atoms plane is remarkably wavy (Δz = 0.224Å). tetrahedral ring distortion affects not only the topology of the cleavage plane, but also the coordination of the interlayer cation, which reduces from twelve to eight. Crystal chemical modifications at mineral surface were investigated via X-ray Photoelectron Spectroscopy (XPS), by comparing data related to surface to the ones characterizing the bulk. A peculiarity of muscovite from Antarctica is a limited Na for K interlayer substitution, which was found in the bulk as well as on the mineral surface. It is well known that in micas the coordination of the interlayer cation can vary from twelve to six, depending on the distortion of the hexagonal tetrahedral ring, as measured by angle, as observed and predicted by Weiss et al. [1].The interlayer cation K (binding energy = 293.36 eV) is confirmed to be eight-fold coordinated [2]. Na (binding energy = 1071.02 eV) substitutes K both in the bulk and at the surface. Na coordination, at mineral surface, reduces from eight to six [3]. The six-fold coordination presented by Na is consistent with ≈ 16°, which is typical for paragonite, whose interlayer is completely occupied by Na. Chemical composition at the surface was compared to bulk chemical composition obtained by electron microprobe analysis. This comparison highlights a decrease in K content, which can be explained by its location on the cleavage surface, since the cation is expected to be distributed equally along the two surfaces generated after cleavage, and an increase in Na which can be related to Na domains close to the cleavage surface.These aspects may relate muscovite cleavage processes to the presence of “defects”, or better in-homogeneities in layer crystal chemistry. This fact may thus suggest that Na content in paragonitic muscovite could not be only attributed to a solid solution mechanism, where this cation substitutes for K, but rather to the presence of Na-dominant clusters.
2011
- Crystal chemistry of lizardite-1T from Northen Apennines Ophiolites (Italy)
[Abstract in Rivista]
Laurora, Angela; Brigatti, Maria Franca; Malferrari, Daniele; Galli, Ermanno; Rossi, Antonio; M., Ferrari
abstract
This study investigates the crystal chemical features of six lizardite-1T crystals sampled in four ophiolitic outcrops (Pompeano, Sassomorello, Varana, and Santa Scolastica) in the Modena Apennines (Italy).Notwithstanding the extensive contributions already present in literature, this is the first study dealing with lizardites from Modena ophiolites. As evidenced by one of our samples, the whole rock composition affects lizardite composition, which results to be sensible to the overprint of secondary, metasomatic events. In our study, particular attention was devoted to the effects of octahedral Fe for Mg and of Si-1Al(Mg,Mn,Fe)2+-1 (Al,Cr,Fe)3+ exchange mechanisms on the structure. Our results suggest that Fe for Mg substitution induces an increase in the octahedral M-O4 length, and a decrease in the octahedral site distortion. Both these effects are also observed to influence unit-cell parameter c. The effect of the Si-1 Al(Mg,Mn,Fe)2+-1(Al,Cr,Fe)3+ substitution is a decrease in the M-O1 distance and a concomitant increase in the T-O1 distance.
2011
- Determination of Hg binding forms in contaminated soils andsediments: state of the art and a case study approachingabandoned mercury mines from Mt. Amiata (Siena, Italy)
[Articolo su rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Elmi, Chiara; Laurora, Angela
abstract
This paper, after an introduction about the state of the art in the methods for the evaluation of Hg chemical speciation,focuses on Hg polluted soils and sediments from Siele mining area (Piancastagnaio, Siena, Italy). In particular, the mineralogicalcomposition was evaluated via X-ray powder diffraction, total Hg was determined via inductively coupled plasma optical emissionspectroscopy on acid digested samples, and Hg binding forms were investigated both via sequential selective extraction andpyrolytic extraction. Solutions obtained via sequential selective extraction were checked for Hg content using inductively coupledplasma optical emission spectroscopy, whereas to carry out pyrolytic extraction a thermogravimetric analyser coupled with anevolved gas mass spectrometer was used. To our knowledge, this last method was never used for this purpose on natural samples.Experimental results enhance that: i) Hg detection via thermal analyses can qualitatively distinguish among different Hg compounds.ii) The temperature of Hg thermal release is affected by both the sample matrix and the Hg bond type. iii) Thermal analysesfail in the attempt of a quantitative determination of the evolved species; this goal is better achieved via the selective chemical leaching.iv) Most of the Hg is related to HgS-like bonds, thus pointing to the presence of very stable Hg compounds. v) Only in somesamples we found also organo-complexed Hg-like compounds and, in a limited amount, hydrosoluble Hg and/or Hg species solublein weakly acid environment. vi) No correlation between sampling point and both total Hg and/or Hg speciation was observed.
2011
- High-temperature vesuvianite: crystal chemistry and surfaceconsiderations
[Articolo su rivista]
Elmi, Chiara; Brigatti, Maria Franca; Pasquali, Luca; Montecchi, Monica; Laurora, Angela; Malferrari, Daniele; Nannarone, Stefano
abstract
A multi-methodical approach has been appliedfor characterizing the bulk and surface crystal chemical featuresof a high-temperature vesuvianite crystal from skarns ofMount Somma-Vesuvius Volcano (Naples, Italy). Vesuvianitebelongs to the space group P4/nnc with unit cellparameters a = 15.633(1)A ° , c = 11.834(1)A ° and chemicalformula (Ca18.858 Na0.028 Ba0.004 K0.006 Sr0.005 h0.098)19.000(Al8.813 Ti0.037 Mg2.954 Mn0.008 Fe0.1142? Fe1.3753? Cr0.008B0.202)13.511 Si18.000(O0.261 F0.940 OH7.799)9.000. Structurerefinement, which converges at R = 0.0328, demonstrates astrong positional disorder down the fourfold axes, indicatingthat the Y1 site is split into two positions (Y1A and Y1B)alternatively occupied. However, because of X4 proximity toY1B and Y1A, X4 cannot be occupied if Y1B or Y1A are.OverallY1 occupancy (Y1A ? Y1B) reaches approximately0.5, as common in vesuvianite and occupancy of Y1B site isextremely limited. Moreover, T1 position, limitedly occupied,accommodates the excess of cations generally related toY position. A small quantity (0.202 apfu) of boron is sited atthe T2 site that, like T1, is poorly occupied. The determination of the amount of each element on the (100)vesuvianite surface, obtained through X-ray photoelectronspectroscopy high-resolution spectra in the region of the Si2p,Al2p, Mg1s, and Ca2p core levels, evidences that a greateramount of aluminum and a smaller amount of calciumcharacterize the surface with respect to the bulk. Althoughboth of these features require further investigation, we mayconsider the Al increase can be related to preferential orientationof Al-rich sites on the (100) plane. Furthermore, thesurface structure of vesuvianite suggests that Al, Ca, and Mgcations maintain coordination features at the surface similarto the bulk. Silica, however, while presenting fourfold coordination,shows also a [1]-fold small coordinated componentat binding energy 99.85 eV, due to broken Si–O bonds at thesurface. The presence of eight- and nine-coordinated Cacations is suggested by a large XPS feature resulting from themerging of Ca2p3/2 and Ca2p1/2 peaks at 348.45 and352.05 eV, respectively.
2011
- Layer charge location in layer silicates and its implications
[Abstract in Rivista]
Elmi, Chiara; Brigatti, Maria Franca; Malferrari, Daniele
abstract
Layer charge value and location are commonly considered key factors for predicting interaction of layer silicates with external agents, such as, for example, pollutants, bio-molecules, and, more generally, ionic complexes. Several methods are discussed in literature for the experimental determination of layer charge, always, however, giving an average value from the different micro-crystals used for the analysis. The most commonly used methods are: the structural formula method [1, 2], the alkylammonium method [3] and the potassium saturation method [4]. The purpose of this paper is to demonstrate that the determination of the average value of the layer charge can sometimes lead to inconsistent results, as not correctly representing the layer charge location at mineral surface. This goal was achieved by analyzing crystal chemical results obtained from different crystals of muscovite characterized by a different content of celadonitic substitution. Muscovite sometimes presents heterovalent substitutions both in tetrahedral (e.g., Al3+ for Si4+) and in octahedral sites (e.g., Mg2+, Fe2+, and vacancies for Al in octahedral sites). Our results seem to demonstrate that these substitutions can be ascribed to trioctahedral cells, all occupied by cations different than Al, in a dominating dioctahedral pattern, with cis-octahedral sites entirely occupied by Al and the trans-site vacant. This interpretation suggests that mean layer charge may not represent effective layer charge at mineral surface because it refers not to randomly distributed substitution, but to domains showing different chemistry which can be locally charge-neutralized. Furthermore, also distortion parameters which affect tetrahedral topology and that can also affect the formation of surface complexes, such as alpha angle and delta z oxygen plane flattening, can be different inside a same structure and locally not corresponding strictly to the determined mean value via single crystal diffraction.
2011
- Sodium hexametaphosfate interactions with illite and montmorillonite: preliminary observation on thermal behavior
[Abstract in Rivista]
Castellini, Elena; M., Bert; C., Berthold; Brigatti, Maria Franca; Malferrari, Daniele
abstract
The interaction of an efficient deflocculant, sodium hexametaphosphate (NaHMP), with two different illites (IMt-1 from Silver Hill, Montana USA and from Schwäbisch Hall, Würtenberg Germany) and two different Ca-montmorillonites (STx-1 from Gonzales County, Texas, USA and from Santa Rita, New Mexico, USA) was investigated.Adsorption measurements of the NaHMP anion were performed onNa-exchanged illite IMt-1 as a function of temperature by means of inductively coupled plasma technique (I.C.P.). The thermodynamic parameters of the adsorption process, together with an estimation of the maximum adsorbed amount on the Na-illite were obtained and compared to the corresponding data previously obtained for Na-kaolinite.The effect of NaHMP on the natural illites and montmorillonites was analyzed using different techniques. I.C.P. measurements of the concentration of P, Na, Si, Al, Ca, Mg, and K of the deflocculant solutions in contact with the clays were performed in order to detail the adsorption, dissolution and exchange phenomena which accompany the deflocculant activity.Thermal analysis (thermo-gravimetric, thermal-differential) and XRD measurements at non ambient temperature conditions were used to characterize the clay solid samples after the interaction with NaHMP.Thermo-gravimetric analyses indicate that NaHMP-treated illites and montmorillonites are less hydrated than natural samples, whereas the dehydroxilation reaction seems to be not influenced by the NaHMP treatment. Basal periodicity was measured via XRPD diffraction on (00l) oriented mounts of the air-dried samples in the temperature range 25 - 400°C (heating rate 2 °C/min) using a powder diffractometer equipped with an area detector. No significant variation of layer periodicity was observed, thus indicating that NaHMP molecules are adsorbed on the edge and/or in the interlayer without modifying natural layer periodicity.
2011
- Structure and mineralogy of layer silicates: recent perspectives and new trends
[Relazione in Atti di Convegno]
Brigatti, Mf; Malferrari, D; Laurora, A; Elmi, C
abstract
Because of their many novel and advanced applications, there is increasing interest in layer silicates from the scientific and technical communities. Appropriate application of these minerals requires deep understanding of their properties and of the processes where they are involved. This chapter, by providing fundamental definitions and crystal structural and chemical data pertaining to layer silicates, aims to introduce this field to new researchers and technicians, by describing the fundamental features leading to different behaviours of layer silicates in different natural or technical processes. The subject addressed is vast and so the reader is referred in some cases to work already published. The focus here is on layer silicates for which detailed crystal structures are given in the literature and which are likely to be used in an applied way in the future. Layer-silicate minerals fulfilling these requirements are: (1) kaolin-serpentine group (e. g. kaolinite, dickite, nacrite, halloysite, hisingerite, odinite, lizardite, berthierine, amesite, cronstedtite, nepouite, kellyite, fraipontite, brindleyite, guidottiite, bementite, greenalite, caryopilite; minerals of the pyrosmalite series); (2) talc and pyrophyllite groups (e. g. pyrophyllite, ferripyrophyllite, willemseite); (3) mica group (i.e. some recent advances in crystal chemistry and structure of dioctahedral and trioctahedral micas); (4) smectite group (e. g. montmorillonite, saponite, hectorite, sauconite, stevensite, swinefordite); (5) vermiculite group; (6) chlorite group (e. g. trioctahedral chlorite such as clinochlore, di,trioctahedral and dioctahedral chlorites such as cookeite and sudoite); (7) some 2: 1 layer silicates involving a discontinuous octahedral sheet and a modulated tetrahedral sheet such as kalifersite, palygorskite and sepiolite; and (8) imogolite and allophane.
2011
- Textural study of metamorphic rocks by means of a conventional X-ray source
[Abstract in Rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Laurora, Angela; R., Sassi; F. P., Sassi
abstract
The aim of this study is the textural characterization of very low togreenschist facies metamorphic rocks by means of a conventional X-ray source, possibly establishing a relationship between the extent of morphological orientation of mineral grains and metamorphic degree.For a long time geologists investigated the morphological orientation of mineral grains in polycrystalline rocks by means of petrographic microscope equipped with a Universal stage. More recently diffraction of conventional X-ray sources as well as diffraction (or transmission) of hard X-rays, electrons and neutrons has been applied to these kind of study.However, whereas X-ray conventional sources can be regarded as a routine technology, hard X-ray, electron and neutron sources are only available in a few facilities around the world.Phyllosilicates such as smectite, illite, muscovite, chlorite and biotite play a key role in the textural characteristics of the mineral assemblages of rocks characterized by increasing metamorphic degree. The present study is focused on the variation of the X-ray intensities of selected reflections of these phases. In short, if a morphologic orientation of the grains of a certain phyllosilicate is present, a variation of the intensity of these reflections will be measured when the rock sample is rotated in a goniometer keeping constant both the incident beam angle and the position of the detector.The samples selected for the study are the following: 1) a Ms, Chl, Qtz, Pl fine grained metapelite from Frassenetto (UD, Italy) (very low grade metamorphism, Anchizone) with some detrital muscovite flakes recognizable by their coarser grain size; 2) Ms, Chl, Qtz, Pl fine grained metapelite from Chiadenis (UD, Italy) (low grade metamorphism, Epizone) with some detrital muscovite flakes recognizable by their coarser grain size; 3) a Ms, Chl, Ilm, Qtz, Pl layered phyllite from Villabassa (BZ, Italy) (Greenschist facies metamorphism, Ms-Chl-Bt), with crenulated main foliation and axial planes defining a second spaced foliation; 4) a Ms, Bt, Grt, Ilm, Qtz, Pl layered phyllite from Luson (BZ, Italy) (Greenschist facies metamorphism, Ms-Bt-Grt), with crenulated main foliation and axial planes defining a second spaced foliation.
2011
- The crystal chemistry of lizardite-1T from Northern Apennines ophiolites near Modena, Italy
[Articolo su rivista]
Laurora, Angela; Brigatti, Maria Franca; Malferrari, Daniele; Galli, Ermanno; Rossi, Antonio; Ferrari, M.
abstract
We investigated the crystal-chemical features of six crystals of lizardite-1T sampled in four outcrops of ophiolite, atPompeano, Sassomorello, Varana, and Santa Scolastica, in the Modena Apennines, Italy. In spite of the extensive contributionsalready present in the literature, this is the first study dealing with lizardite from the Modena ophiolites. As is clear from one ofour samples, the whole-rock composition affects the composition of lizardite, which makes it susceptible to overprinting by latermetasomatic events. In our study, we paid particular attention to the effects of VIMg–1VIFe2+ and of IVSi–1 IVAl VI(Mg, Mn, Fe)2+–1VI(Al, Cr, Fe)3+ exchange mechanisms on the structure. Our results suggest that VIMg–1VIFe2+ substitution induces an increase inthe M–O4 length in octahedra and a decrease in the octahedral-site distortion. Both these effects are also observed to influencethe unit-cell parameter c. The effect of the IVSi–1 IVAl VI(Mg, Mn, Fe)2+–1 VI(Al, Cr, Fe)3+ substitution is to decrease the M–O1distance and concomitantly, to increase the T–O1 distance.
2010
- Crystal chemistry, surface morphology and X-ray photoelectron spectroscopy of Fe-rich osumilite from Mt. Arci, Sardinia (Italy)
[Articolo su rivista]
Elmi, Chiara; Brigatti, Maria Franca; Pasquali, Luca; Montecchi, Monica; Laurora, Angela; Malferrari, Daniele; Nannarone, Stefano
abstract
Microprobe anal., single crystal X-ray diffraction, XPS, at. force microscopy, and X-ray absorption spectroscopy were applied on Fe-rich osumilite from the volcanic massif of Mt. Arci, Sardinia, Italy. Osumilite belongs to the space group P6/mcc with unit cell parameters a = 10.1550(6), c = 14.306(1) Å and chem. formula (K0.729)C (Na0.029)B (Si10.498 Al1.502)T1 (Al2.706 Fe0.2942+)T2 (Mg0.735 Mn0.091 Fe1.1842+)AO30. Structure refinement converged at R = 0.0201. Unit cell parameter a is related to octahedral edge length as well as to Fe2+ content, unlike the c parameter which does not seem to be affected by chem. compn. The detn. of the amt. of each element on the mineral surface, obtained through XPS high-resoln. spectra in the region of the Si2p, Al2p, Mg1s and Fe2p core levels, suggests that Fe presents Fe2+ oxidn. state and octahedral coordination. Two peaks at 103.1 and 100.6 eV can be related to Si4+ and Si1+ components, resp., both in tetrahedral coordination. The binding energy of Al2p, at 74.5 eV, indicates that Al is mostly present in the distorted T2 site, whereas the Mg peak at 1,305.2 eV suggests that this cation is located at the octahedral site. X-ray absorption at the Fe L2,3-edges confirms that iron is present in the mineral structure, prevalently in the divalent state and at the A octahedral site.
2010
- Effect of temperature on Hg-cysteine complexes in vermiculite and montmorillonite
[Articolo su rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Marcelli, A.; Chu, W.; Wu, Z.
abstract
This study describes the influence of temp. on two Hg(II)-cysteine modified clay minerals with different layer charges (i.e., montmorillonite and vermiculite) by using chem. and thermal analyses coupled with evolved gas mass spectrometry (TGA-MSEGA), synchrotron-based X-ray absorption spectroscopy (XAS), and X-ray powder diffraction (XRPD) techniques; these two latter techniques were applied on samples heated "in situ" up to 900 °C. Hg bonds cysteine by the thiol group with Hg-SH bond lengths similar in both clay minerals, thus suggesting their independence from layer charge. On the contrary, the thermal behavior of the adsorbed organometallic complexes was strictly layer charge dependent, as evidenced by decompn. temps., which were lower in montmorillonite than in vermiculite. Results from X-ray absorption near edge structure (XANES) spectroscopy evidenced nearly complete Hg desorption in montmorillonite between 600 and 700 °C, unlike in vermiculite where Hg was still present at these values.
2010
- Effect of temperature on Hg-cysteine complexes in vermiculite and montmorillonite
[Abstract in Atti di Convegno]
Malferrari, Daniele; Brigatti, Maria Franca; Marcelli, A.; Chu, W.; Wu, Z.
abstract
This work describes the influence of temperature on two Hg(II)-cysteine modified clay minerals with different layer charge (i.e.,vermiculite and montmorillonite) by using chemical analyses,thermal analyses coupled with evolved gas mass spectrometry(TGA-MSEGA), synchrotron-based X-ray absorptionspectroscopy (XAS), and X-ray powder diffraction (XRPD)techniques. These two latter techniques were applied onsamples heated “in situ” up to 900°C. Hg binds cysteine by thethiol group with Hg–SH bond lengths similar in both clayminerals, thus suggesting their independence from layer charge.On the contrary, the thermal behaviour of the adsorbedorganometallic complexes is strictly layer charge dependent, asevidenced by decomposition temperatures, which are commonlylower in montmorillonite than in vermiculite. Results from Xrayabsorption near edge structure (XANES) spectroscopyevidence a nearly completely Hg removal in montmorillonite attemperature values ranging from 600 to 700°C, unlike invermiculite where Hg is still present at these temperatures.
2010
- Relationship between morphological preferred orientations and landslides
[Abstract in Atti di Convegno]
Bortolotti, D.; Brigatti, Maria Franca; Elmi, Chiara; Malferrari, Daniele; Pattuzzi, Edda
abstract
Crystals orientation in polycrystalline natural compounds maybe either completely random or else follow preferred directions,which reflect physical processes in which the materials havebeen involved during the solidification and / or after the solidstate had been reached.The preferred orientation can be divided into two maingroups: i) preferred orientation of the crystal lattice (LPO,lattice preferred orientation) and ii) grains preferred orientation(i.e., morphological preferred orientations, MPO). Frequentlythere is a close relationship between these two groups.Geological processes that determine the formation of LPO are,for example, tectonic (regional) compressive movements; on theother hand MPO can be induced also by local stress (i.e.,gravitational movements). While tectonic (regional)compressive movements may produce LPO even on alreadylithified rocks, usually, MPO are induced only on not-lithifiedand incoherent rocks.The preferred orientation cab be observed: i)macroscopically (the rock structures) ii) microscopically, grainsorientation and morphological textures of the rock according tothe classic concept of optical microscopy, iii) with diffractionmethods (i.e., X-rays and neutrons diffraction), to study bothLPO and MPO when, this last, cannot be studied via opticalmethods because, for example, of a very small grain size.This research will investigate MPO via X-ray diffractiononly. We collected, and kept oriented, samples in severallandslide areas. In particular samples were collected both in theactive crumbling area and at the landslide margin. Sampleswere analyzed for texture using X-ray diffractometer equippedwith a phi-chi Eulerian cradle. We analyzed the preferredorientation of the hkl reflections: i) (001) and (060) in smectitiand illite; ii) (001) and (100) in caolinite; iii) (24-1) inplagioclase.Preliminary investigation demonstrated a direct correlationbetween the number of MPO and the amount of clay minerals.Texture measurements on samples collected in the crumblingarea agree with other morphological field measurements,providing, in addition to the main direction of the landslide, alsothe vertical module, thus probably defining the preferential pathfor interstitial fluids migration. Only in one case we couldobserve preferred orientation in a sample coming from a marginof a landslide, data which could testify a past movement (paleolandslide) or else a quiescent landslide.
2010
- Surface structure of natural muscovite
[Abstract in Atti di Convegno]
Elmi, Chiara; Brigatti, Maria Franca; Malferrari, Daniele; Castro, G. R.; Ferrer Escorihuela, P.
abstract
The aim of this project is to study the atomic surface structure of a natural muscovite crystal thanks to the synchrotron radiation light and the grazing incidence X-ray diffraction (GIXRD).The muscovite studied [(K0.92Na0.08) (Al1.86Fe3+0.01Mg.0.07 Fe2+0.06Ti0.02) (Si3.03Al0.97) O10 F0.09 (OH)1.91] is monoclinic, 2M1 polytype, with symmetry C2/c and unit cell parameters a = 5.19690(10) b = 9.0138(3) c = 20.0835(7) (Å) and β = 95.763(2) (°).The muscovite structure was refined by single crystal X-ray diffraction and the final refinement yielded the following agreement factor R = 0.0299. The difference Fourier map shows a significant residual electron density (2.2-) close to the position related to M1 site, thus indicating that the excess of octahedral cations is located at M1. M1-O mean bond distance is 2.247(9) and M2-O distance is 1.929.Grazing incidence X-ray diffraction (GIXRD) was recently performed at SpLine at ESRF. This type of analysis is very useful to identify typical structural features of the surface, such as possible imperfections, relaxations or reconstructions. Usually, the atoms on surfaces, and sometimes those as deep as several layers down, assume positions different from their equilibrium positions in the bulk. Generally mineral surfaces will not be reconstructed unless they have been heated to temperature higher than 100 °C. In our case, the muscovite surface has been exposed to a delay of the first layer in order to study a freshly cleaned surface and data collected by GIXRD confirm that on muscovite surface only a relaxation occurs from an equivalent plane in the bulk. This is a common case for minerals with a low-symmetry structure as the feldspar surface.
2010
- The relationships of bulk structure, surface structure, chemistry, and physical properties of mineral phases with six- and eight-membered silicate rings
[Abstract in Atti di Convegno]
Elmi, Chiara; Brigatti, Maria Franca; Pasquali, Luca; Montecchi, Monica; Nannarone, Stefano; Laurora, Angela; Malferrari, Daniele
abstract
The goal of this research is to better understand the relationship between chemical composition and atomic structure (both bulk and surface structure) of minerals having six-membered silicate rings, such as osumilite and eight-membered silicate rings, such as vesuvianite. Osumilite under investigation occurs in thin fissures within a rhyolite from the volcanic massif of Mt. Arci, Sardinia (Italy). Vesuvianite sample is from skarns of Somma-Vesuvius volcano (Italy) instead.The osumilite and vesuvianite bulk structures were refined via single crystal X-ray diffraction. Osumilite sample is hexagonal, with symmetry P6/mcc and unit cell parameters a = 10.1550(6) c = 14.306(1) (Å). The structural formula is (K0.729)C (Na0.029)B’ (Si10.498 Al1.502)T1 (Al2.706 Fe2+0.219 Mg0.075)T2 (Mg0.660 Mn0.091 Fe2+1.258)AO30. When compared to literature data [1], osumilite sample from Mt. Arci is characterized by a significantly high Fe2+ content (1.478 apfu).X-ray photoelectron spectroscopy (XPS) enabled the crystal chemical characterization of osumilite surface, where iron was still observed in its divalent state, thus confirming a similarity in osumilite surface and bulk chemical composition. A further evidence of Fe oxidation state at osumilite surface is provided from X-ray absorption spectroscopy (XAS) at Fe-L2,3 edge.Vesuvianite is a complex tetragonal silicate. Vesuvianite ideal formula is Ca19(Al,Mg)13(B, Si)18O68(OH, O, F)10 and crystallizes, generally, in the space group P4/nnc. Vesuvianite presents in nature two different structural type: a high temperature type (at about 1000 °C) and a low temperature type (at about 900 °C). To recognize which type of vesuvianite, our sample belongs to, we studied its thermal decomposition via X-ray powder diffraction method by using a Philips X’Pert PRO diffractometer equipped with X’Celerator area detector. Finally we could assure that our sample is a high temperature vesuvianite with high symmetry P4/nnc.Unlike osumilite, vesuvianite surface is very complex to study because of its roughness on given faces of the crystal. However we could obtain preliminary information on the chemical composition of the surface via XPS and subsequently compare these data to bulk chemical composition. Moreover, unlike osumilite sample, vesuvianite presents Fe in octahedral site both in divalent and trivalent state, as confirmed by XAS experiments performed at the L2,3 edge of iron.
2010
- Trioctahedral micas: relationships between crystal chemistry and magnetic behavior
[Abstract in Atti di Convegno]
Affronte, Marco; Brigatti, Maria Franca; Malferrari, Daniele; Marcelli, A.; Pini, S.
abstract
This study is aimed at verifying the factors affecting magneticsusceptibility χ variation in micas in relation to: I) Fe content;ii) Fe2+/Fe3+ ratio; iii) occurrence of Fe in tetrahedral andoctahedral sites, outlining possible ordering effects.Other aspects considered in our study will involve: i)eventually observed variation in magnetic properties forsamples showing similar chemical composition, but occurringfrom different areas and different crystallization environments;ii) possible influence of strong magnetic anomalies overmagnetic properties of samples therein occurring.All these aspects were thus addressed by characterizingsamples belonging to phlogopite – annite, tetra-ferriphlogopite– tetra-ferri-annite and polylithionite – siderophylliteseries. Some samples, representative of the whole sample set,were then selected for magnetic susceptibility characterization.Some of them also required calorimetric analyses, in order tobetter describe and understand their behaviour.Other experimental methods used in this investigationinclude: electron microprobe, structure resolution by X-raysingle crystal methods, X-ray absorption spectroscopy, with aparticular attention to the understanding of the XANES region.Main results demonstrate that: i) magnetic phenomenaassociated with maxima of magnetic susceptibility could beobserved at low temperature (T<10 K) and weak magnetic field(10 Oe); ii) magnetic properties depend not only on the total Fecontent. Samples where Fe is mostly in octahedral coordinationare predominantly ferromagnetic, strongly depending on the[6]Fe2+/([6]Fe2++[6]Fe3+) ratio, which was observed to increasewith Curie-Weiss θ constant (ranging from 13 to 24 K and from4.4 and 5.2 K for samples showing higher and lower[6]Fe2+/([6]Fe2++[6]Fe3+) ratio, respectively). In tetra-ferriphlogopite,dominant interactions were observed to be antiferromagnetic,as shown by a negative Curie-Weiss θ constantvalue (-25 K). Furthermore Curie-Weiss constant (θ) and thetemperature value giving the maximum in the magneticsusceptibility (Tm) seem to be dependent not only on the meannumber of Fe atoms in octahedral coordination (Z) per unit cell,but also on its ordering. Tm linearly depends on severalstructural parameters as well, e.g., the tetrahedral rotation angle α.
2010
- Use of perlite in combination with clays for the production of low environmental impact filter for heavy metals polluted aqueous solution
[Abstract in Atti di Convegno]
Marchetto, Patrizia; Brigatti, Maria Franca; Laurora, Angela; Malferrari, Daniele
abstract
The aim of this work is to prepare a relatively cheap mixture ofperlite (a volcanic rock with intermediate composition betweenrhyolite and dacite) and clays, effective in the retention of heavymetals even after treatments at relatively high temperatures. Theobtained product could be possibly reused and therefore notdisposed of as toxic waste. The perlite used in this study comesfrom Greek quarries and is provided by the company "PerliteItaliana”. Three different types of clay materials were used: 1) aclay material coming from the Argille Varicolori formation; 2) acommercial bentonite (supplied by Laviosa, Italy; 3) a standardmontmorillonite (STx-1, from the County of Gonzales, Texas,USA), to be used as reference materials.Column and batch tests were carried out on several differentmixtures of the previously described materials in order toevaluate the effective adsorption of Cd, Pb, and Zn fromaqueous solution. Pb, Zn, and Cd contents of the “polluted”mixtures were thus measured via inductively coupled plasmaoptical emission spectroscopy (ICP-OES) after acid digestion.The obtained results indicate that the mixture consisting ofVaricolori clay and perlite can be profitably used as adsorbentof metals in solution. Adsorption data are consistent with thoseexpected from theoretical calculations.The method chosen for the permanent inertization ofpolluted samples is thermal treatment, which, as evidenced bynumerous literature data, can lead to a chemically inert product,eventually suitable for reuse in construction. Before being fired,each mixture was added from opportune amount of kaoliniteand feldspar. Release tests were, thus, carried out on firedproducts using weakly acid solution (pH values between 5.5.and 6) as leaching media. Results, which are very encouraging,are reported in the Table 1.
2009
- Approvvigionamento idrico e manutenzione delle infrastrutture idrauliche di bonifica: il problema dello smaltimento dei sedimenti dei canali
[Relazione in Atti di Convegno]
Malferrari, Daniele; Pistoni, Roberto; Laurora, Angela; Brigatti, Maria Franca; Mantovani, E.; Tonelli, F.
abstract
Questo studio si occupa dell’inquinamento dei sedimenti provenienti dal fondo dei canali situati nella parte settentrionale delle province di Modena e Ferrara (Italia). L’accumulo dei sedimenti (20 mm/anno ca.) è dovuto al drenaggio e alla canalizzazione delle acque per l’irrigazione. Per mantenere i canali in piena efficienza, i sedimenti devono essere periodicamente rimossi; se la concentrazione degli inquinanti (metalli pesanti) è superiore ai limiti di legge, i sedimenti devono essere stoccati alla stregua di rifiuti industriali. Tuttavia al momento non vi è un sito adeguato ad ospitare questa enorme quantità di sedimenti, e le amministrazioni locali non sarebbero in grado di affrontare i costi dello smaltimento. Il presente studio si propone di: i) effettuare una caratterizzazione approfondita dei sedimenti, ossia di determinare la speciazione chimica degli inquinanti in essi contenuti, per mezzo di una procedura di estrazione sequenziale e di analisi EXAFS, ed in questo modo, di valutarne il reale impatto ambientale; ii) mettere a punto un sistema per inertizzare i sedimenti inquinati e, allo stesso tempo, cercare un modo per re-impiegarli. Le analisi chimiche e le estrazioni sequenziali rivelano che lo Zn è il più ubiquitario ed abbondante tra i metalli pesanti, mentre Cd e Hg sono presenti in quantità molto limitate. Tutti i metalli pesanti esaminati (Cd, Cr, Cu, Hg, Ni, Pb and Zn) non sono facilmente rilasciati (piccole quantità sono adsorbite sulla superficie o nell’interstrato della smectite) ma neppure formano molecole stabili a lungo termine; infatti, le estrazioni sequenziali e le analisi EXAFS rivelano che i metalli pesanti sono soprattutto legati alla superficie di ossidi e idrossidi ed alla sostanza organica.Dall’analisi mineralogica risulta che I sedimenti sono principalmente costituiti da quarzo e minerali delle argille (smentite, clorite ed illite). Ad eccezione della materia organica, la cui presenza può essere drasticamente ridotta semplicemente immagazzinando i sedimenti in ambiente ossidante (ad esempio in atmosfera), la composizione mineralogica (e chimica) dei sedimenti è adeguata alla produzione di piastrelle e, soprattutto, di laterizi. Per mezzo di numerosi test finalizzati ad ottimizzare le procedure di produzione di piastrelle e laterizi, sono stati ottenuti risultati incoraggianti. I test di rilascio (leaching per mezzo di soluzioni acide) rivelano che tutti I metalli pesanti sono sostanzialmente trattenuti (il valore più elevato è quello del Cr, da 0.5 a 1.5μg/g).
2009
- CRYSTALLOGRAPHIC FEATURES AND CLEAVAGE NANOMORPHOLOGY OF CHLINOCHLORE: SPECIFIC APPLICATIONS
[Articolo su rivista]
G., Valdré; Malferrari, Daniele; Brigatti, Maria Franca
abstract
This work firstly investigates the relationships between clinochlore cleavage characteristics, in terms of nano-morphology and surface potential, and its average crystal chemistry and topology. Secondly, it shows that the structural features of clinochlore can be successfully used to condense, order and self assemble complex biomolecules, such as DNA. A natural IIb-4 clinochlore [ symmetry, unit cell parameters a = 0.53301(4); b = 0.92511(6); c = 1.4348(1) (nm); alpha = 90.420(3); beta = 97.509(3); gamma = 89.996(4) (°)] with chemical composition (Mg1.701 Fe2+0.245 Ti0.004 Al0.998 Cr3+0.052) Mg3 (Si2.939 Al1.015 Fe3+0.046) O10 (OH7.913 F0.087) was selected. The octahedral sites of the silicate layer (<M(1) - O> = 0.2080 nm and <M(2) - O> = 0.2081 nm) are equal and occupied by Mg, whereas the octahedral sites in the interlayer M(3) and M(4) (<M(3) - O> = 0.2088 nm and <M(4) - O> = 0.1939 nm) show different size and are mostly completely occupied by divalent (Mg and Fe2+) and trivalent (Al3+) cations, respectively.The clinochlore cleaved surface presents two types of patterns: (i) stripe type (about 0.40 nm in height, up to several micrometers long and ranging from some nanometers to a few microns in lateral size), and (ii) triangular-saped-type (about 0.40 nm in height). Both features may result either from interlayer sheets whose cleavage weak directions are related to the different M(3) and M(4) site occupancy, or from interlayer weak bonding along specific directions to the underneath 2:1 layer. The cleaved surface, particularly at the cleaved edges, presents high DNA affinity, which is directly related to an average positive surface and ledge potential.
2009
- Combined mineralogical and EXAFS characterization of polluted sediments for the definition of technological variables and constraints
[Abstract in Rivista]
Brigatti, Maria Franca; Elmi, Chiara; Laurora, Angela; Malferrari, Daniele; L., Medici
abstract
An extremely severe aspect, both from environmental and economic viewpoint, is the management of pollutedsediments removed from drainage and irrigation canals. Canals, in order to retain their functionality over the time,need to have their beds, periodically cleaned from sediments there accumulating. The management of removedsediments is extremely demanding, also from an economical perspective, if these latter needs to be treated asdangerous waste materials, as stated in numerous international standards. Furthermore the disposal of such a largeamount of material may introduce a significant environmental impact as well. An appealing alternative is the recoveryor reuse of these materials, for example in brick and tile industry, after obviously the application of appropriatetechniques and protocols that could render these latter no longer a threat for human health. The assessment ofthe effective potential danger for human health and ecosystem of sediments before and after treatment obviouslyrequires both a careful chemical and mineralogical characterization and, even if not always considered in the internationalstandards, the definition of the coordination shell of heavy metals dangerous for human health, as afunction of their oxidation state and coordination (e.g. Cr and Pb), and introducing technological constraints oraffecting the features of the end products. Fe is a good representative for this second category, as the features ofthe end product, such as color, strongly depend not only from Fe concentration but also from its oxidation state,speciation and coordination. This work will first of all provide mineralogical characterization of sediments fromvarious sampling points of irrigation and drainage canals of Po river region in the north-eastern of Italy. Sampleswere investigated with various approaches including X-ray powder diffraction under non-ambient conditions, thermalanalysis and EXAFS spectroscopy. Obtained results, and in particular EXAFS spectra were used to define andoptimize the technological variables of the recovery process.
2009
- Crystal chemistry of trioctahedral micas in the top sequences of the Colli Albani volcano, Roman Region, central Italy
[Articolo su rivista]
Laurora, Angela; Malferrari, Daniele; Brigatti, Maria Franca; A., Mottana; E., Caprilli; G., Giordano; R., Funiciello
abstract
Trioctahedral mica crystals are frequently found in the volcanoclastic products emplaced during the final stages of the activity of the Colli Albani volcano (Roman Region, central Italy). In the youngest phreatomagmatic deposits, mica is found either as a minor mineral phase in holocrystalline ejecta, scoriae, and coherent pyroclastics, or as loose mica phenocrysts in incoherent pyroclastics. Based on optical and electron microscope investigations, as well as crystal chemical and structural data, the micas selected for this study were divided into two groups, the first one encompassing brownish, Fe-rich crystals (type-A phlogopites, hereafter referred as t-A) with 0.68 < Mg/(Mg+Fetotal) < 0.85 and 0.062 < Tiapfu < 0.199, and the other one encompassing colorless, Mg-rich crystals (type-B phlogopites, hereafter referred as t-B) with Mg/(Mg+Fetotal) in excess of 0.85 and 0.007 < Tiapfu < 0.052. t-A phlogopites also show a tetrahedral ring cavity, overlapped tetrahedral hexagon area, and basal tetrahedron area greater than in the t-B phlogopites.From a petrological point of view, the textural and chemical variations of t-A phlogopites are compatible with fractional crystallization processes taking place within the magma chamber. t-B phlogopites show evidence of a Ti-oxy substitution mechanism, thus suggesting high fO2 conditions. Textural and paragenetic features observed in t-B phlogopite-bearing rock samples, indicate a genesis by thermal metamorphism of a siliceous dolomitic limestone with the input of a variable amount of a potassic magma, possibly the same from which the t-A phlogopites formed, with the exception of one sample, for which a different parental magma is suggested. Indeed, there is an almost continuous spectrum of crystal-chemical and structural parameters starting from t-B and evolving towards t-A phlogopites. The t-A phlogopites displays complex, apparently meaningless relationships in their crystal-chemical parameters, thus indicating interplay of several substitution mechanisms. They possibly formed in polybaric conditions, since their cell volumes differ, but the total size of the cations hosted in the octahedral sheet is the same.
2009
- Heavy metals in sediments from canals for water supplying and drainage: mobilization and control strategies
[Articolo su rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Laurora, Angela; Pini, Stefano
abstract
One of the most critical aspects of the maintenance of canals forwater supplying and drainage is the managingof deposited sediments, which must be periodically removed. Deposited sediments, if containinganthropogenic pollutants with a concentration exceeding specific law limits, must be stored as industrialwastes, thus raising additional economic and logistic problems to deal with. Our research considers pollutedsediments from an area close to the south side of Po river, in order to characterize heavy metalsassociated with different mineral species, thus defining effective treatments for their inertization, andsuggesting a possible process for their recycle. Our results demonstrate that the composition of thesesediments is suitable for the production of tiles and bricks. Several testswere thus performed to optimizesample treatment and other process parameters, finally giving very encouraging results. Releasing testson fired products reveal that all the heavy metals are well retained.
2009
- LA DIDATTICA DELLE SCIENZE DELLA TERRA
[Articolo su rivista]
Laurora, Angela; Malferrari, Daniele; Fregni, Paola
abstract
Le Scienze della Terra si dedicano all’osservazione ed alla interpretazione degli eventi geologici che hanno condotto all’attuale stato del pianeta, studiano gli elementi, i minerali e le rocce che lo compongono, si occupano dei rapporti tra l'ambiente e l’uomo, elaborano e propongono modelli di simulazione dell’impatto antropico sul territorio; ed oltre a queste, accolgono in sé numerose altre competenze di cui difficilmente il “non addetto ai lavori” è a conoscenza. Per essere comprese, pertanto, le Scienze della Terra vanno considerate nella loro globalità, ossia come risultante della reciproca integrazione dei numerosi ambiti disciplinari che ne fanno parte.Due sono le vie sperimentate al fine di promuovere una conoscenza di base soddisfacente dell’”universo” delle Scienze della Terra: la prima fondata sulla reciproca collaborazione tra docenti universitari con elevata specificità disciplinare e insegnanti delle scuole primarie e secondarie, e la seconda fondata sull’insegnamento diretto da parte di questi docenti ad alunni delle scuole primarie e secondarie.La sperimentazione didattica descritta in questo articolo è stata strutturata secondo due differenti approcci, che possono essere schematizzati come segue: i) didattica delle Scienze della Terra nell’ambito dell’esperienza del Master in Didattica delle Scienze organizzato presso l’Università degli Studi di Modena e Reggio Emilia, e ii) insegnamento diretto da parte di ricercatori universitari di nozioni di Scienze della Terra a studenti delle scuole primarie, secondarie e di formazione professionale mediante partecipazione attiva degli alunni a percorsi didattici organizzati presso il Dipartimento di Scienze della Terra dell’Università degli Studi di Modena e Reggio Emilia.
2009
- Layer charge and heavy metals structures in hydrated 2 : 1 silicates:state of the art and new advances on cadmium
[Articolo su rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Elmi, Chiara; Laurora, Angela; G., Valdre
abstract
This study will discuss how layer charge can affect chemical speciation and topology of heavy metals adsorbed to 2:1 layer silicates, by providing: i) an overview of literature data; ii) experimental data on Cd complexes adsorbed by 2:1 layer silicates with different layer charge (montmorillonite and vermiculite); iii) a comparison between our results and literature data. This study will also be supported by several different experimental techniques such as chemical and thermal analyses, X-ray powder diffraction and X-ray absorption spectroscopy.Based on our data Cd atoms were found to complex water molecules in both clay minerals and to show four-fold coordination in montmorillonite (CdO distances of 2.24 Å) and six-fold coordination in vermiculite (CdO distances of 2.16 and 2.28 Å). Furthermore our models clearly suggest that Cd mainly bonds to interlayer water, without neglecting the more limited, but still significant, Cd multinuclear surface complexes at the octahedral broken edges. Both clay minerals show H2O/Cd ratio, as evidenced by thermal analyses, drastically higher than expected from X-ray adsorption spectroscopy data, thus implying that most of the water molecules are only loosely coordinated to interlayer cations.
2009
- Mobilization of heavy metals from fluvial sediments (Tiepido river, Modena, Italy): mineralogical and chemical investigation to prevent potential environmental hazard
[Abstract in Rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Laurora, Angela; Venturini, S.
abstract
nd
2009
- Natural Reserves as a tool for the recovery and exploitation of abandoned mining areas: Hg in soils and sediments from Pigelleto (Piancastagnaio, Siena, Italy) Natural Reserve
[Abstract in Rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Laurora, Angela; Zanerini, L.
abstract
nd
2009
- Octahedral cation ordering and magnetic behavior of micas
[Abstract in Rivista]
Pini, S.; Affronte, Marco; Brigatti, Maria Franca; Malferrari, Daniele; Marcelli, A.
abstract
This contribution is finalized at the discussion of the magnetic structure of two samples, belonging to phlogopite–annite [sample TK, chemical composition IV(Si2.76Al1.24) VI(Al0.64Mg0.72 Fe1.452+ Mn0.03Ti0.15) (K0.96Na0.05) O10.67 (OH)1.31 Cl0.02] and polylithionite–siderophyllite joints [sample PPB, chemical composition IV(Si3.14Al0.86)VI(Al0.75Mg0.01 Fe1.032+ Fe1.033+ Mn0.01Ti0.01Li1.09) (K0.99Na0.01) O10.00 (OH)0.65F1.35]. Samples differ for Fe ordering in octahedral sites, Fe2+/(Fe2+ + Fe3+) ratio, octahedral composition, defining a different environment around Fe cations, and layer symmetry. Spin-glass behavior was detected for both samples, as evidenced by the dependency of the temperature giving the peak in the susceptibility curve from the frequency of the applied alternating current magnetic field. The crystal chemical features are associated to the different temperature at which the maximum in magnetic susceptibility is observed: 6 K in TK, where Fe is disordered in all octahedral sites, and 8 K in PPB sample, showing a smaller and more regular coordination polyhedron for Fe, which is ordered in the trans-site and in one of the two cis-sites.
2009
- Osumilite from Mount Arci (Sardinia, Italy): bulk and surface crystal chemistry
[Abstract in Rivista]
Elmi, Chiara; Brigatti, Maria Franca; Pasquali, Luca; Montecchi, Monica; Laurora, Angela; Malferrari, Daniele; Nannarone, Stefano
abstract
This study is focused on osumilite crystal chemistry and on its surface chemical characteristics and properties. Osumilite belongs to the milarite mineral group. This mineral, with the ideal formula XIICIXB’2VIA2(T2)3IV(T1)12O30 crystallizes in the space group P6/mcc. T1 is mainly occupied by Si and to a smaller amount by Al, T2 is usually occupied by Al with Fe and little Mg, whereas A octahedron mostly contains Mg and Fe. The ring arrangement defines structural channels occupied by the twelve-coordinated C site which is characterized by the presence of alkaline cations (Na, K).The osumilite from Mt Arci (Sardinia) occurs in thin fissures and small cavities within a rhyolite from the volcanic massif of Mt. Arci, Sardinia. The mineral forms regular dark blue hexagonal prismatic-tabular crystals associated to trydimite and sporadic phlogopite crystals. The osumilite structure was refined by single crystal X-ray diffraction and the final refinement yielded the following agreement factors R = 0.0199. The sample studied is hexagonal, with symmetry P6/mcc and unit cell parameters a = 10.1550(6) c = 14.306(1) (Å). The structural formula is (K0.729)C (Na0.029)B’ (Si10.498 Al1.502)T1 (Al2.706 Fe2+0.219 Mg0.075)T2 (Mg0.660 Mn0.091 Fe2+1.258)AO30. In respect of data from literature [2], osumilite sample from Mt. Arci is characterized by a significantly high Fe content (1.478 apfu).In order to study the morphology of osumilite from Mt. Arci, an atomic force microscopy (AFM) filtered images of osumilite was performed. The (001) surface roughness of osumilite is about 0.40 nm, thus it confirms the presence of the channels defined by the double rings of tetrahedra. The distance between two dark areas, defining channel position, is 1 nm, which well agree with the unit cell parameter a value.X-ray photoelectron spectroscopy (XPS) analysis was carried out to measure chemical composition and quantity of each element on the osumilite surface. Higher resolution spectra in the region of Si2p, Al2p, Mg1s and Fe2p core levels were measured. From data collected, we could say that the osumilite surface is chemically well characterized and the elemental composition of surface totally corresponds to the bulk chemical composition. Moreover, comparing our results to data from literature we obtained also crystal chemical information on Fe, Mg, Si and Al high resolution spectra, compared to the crystal chemical characteristics of the bulk.In order to confirm the valence of Fe and the position of this element in the A site, X-ray absorption spectroscopy (XAS) was also made in the L2,3 edge of iron comparing data from literature.
2009
- Relationship between bulk and surface structure of muscovite
[Abstract in Rivista]
Elmi, Chiara; Brigatti, Maria Franca; Malferrari, Daniele; Castro, G. R.; Ferrer Escorihuela, P.; Rubio Zuazo, J.
abstract
The aim of this project is to study the relationships between bulk and surface structure of a natural muscovite crystal.The muscovite studied [(K0.92Na0.08) (Al1.86Fe3+0.01Mg.0.07 Fe2+0.06Ti0.02) (Si3.03Al0.97) O10 F0.09 (OH)1.91] is monoclinic, 2M1 polytype, with symmetry C2/c and unit cell parameters a = 5.19690(10) b = 9.0138(3) c = 20.0835(7) (Å) and β = 95.763(2) (°).The muscovite structure was refined by single crystal X-ray diffraction and the final refinement yielded the following agreement factor R = 0.0299. The difference Fourier map shows a significant residual electron density (2.2-) close to the position related to M1 site, thus indicating that the excess of octahedral cations is located at M1. M1-O mean bond distance is 2.247(9) and M2-O distance is 1.929.Grazing incidence X-ray diffraction (GIXRD) was recently performed at SpLine at ESRF. This type of analysis is very useful to identify typical structural features of the surface, such as possible imperfections, relaxations or reconstructions of the surface [1]. Preliminary data collected by GIXRD could indicate that on muscovite surface a reconstruction could occur, but we need more reflections to be certain of this assumption. Some indirect evidence of surface modification of mica crystals may be suggested by a lower K content on mica surface than observed in the bulk, which is a rather common observation when subjecting micas to chemical analyses. K release can also be attributed to a variation of interlayer cavity topology at surface, as well as to a breaking of K-O bonding. This effect can play a significant role in determining surface charge in micas, either completely negative, or partly positive and partly negative, depending on K release.
2008
- Clinochlore structure and its surface interactions with organic molecoles
[Relazione in Atti di Convegno]
Elmi, Chiara; Brigatti, Maria Franca; Malferrari, Daniele; Valdrè, G.; Castro, G. R.; Rubio Zuazo, J.
abstract
This study is focused on clinochlore crystal chemistry and on its surface interactions with biomolecules. Clinochlore, which is a chlorite, is formed by two different polyhedral units: (i) two tetrahedral sheets (T) sandwiching a Mg-rich octahedral sheet (O) and (ii) an octahedral Mg-, Al-rich, brucite-like, interlayer (B). The excess of negative charge of the TOT layer is neutralized by the positively charged B interlayer. Extensive hydrogen bonding provides structural cohesion between the TOT layer and the B interlayer.The clinoclhore studied is triclinic IIb-4 polytype, with symmetry C and unit cell parameters a = 5.3301(4) b = 9.2511(6) c = 14.348(1) (Å) α = 90.42(1) β = 97.51(1) γ = 90.00(2) (°). The chemical composition is [VI](Mg9.6Fe2+0.27Al2.01Cr0.09)[IV](Si5.86Al2.14)O20(OH)16.Measurements of surface reflectivity carried out at ESRF, Spanish beam line, suggest that biological molecules, such as nucleotides, can be adsorbed as (001) organized layer on the mineral surface. Furthermore AFM (Atomic Force Microscopy) and EFM (Electric Force Microscopy) studies suggest that clinochlore presents at the nanoscale, negative regions of exposed oxygens (tetrahedral sheets, lower layer) and positive regions of exposed hydroxyl groups belonging to the brucite-like which is about 0.5 nm thick [1]: the brucite-like layer is more effective in assembling the biological molecules rather than the exposed oxygen surface.
2008
- Crystal chemical modeling and XANES spectroscopy of potassium micas
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Malferrari, Daniele; Mottana, A.; Cibin, G.; Marcelli, A.; Cinque, G.
abstract
nd
2008
- DNA interactions with clinochlore surface
[Relazione in Atti di Convegno]
Valdrè, G.; Brigatti, Maria Franca; Malferrari, Daniele
abstract
nd
2008
- Effect of temperature on Hg- and Hg-cysteine complexes in vermiculite and montmorillonite interlayer
[Relazione in Atti di Convegno]
Malferrari, Daniele; Brigatti, Maria Franca; Elmi, Chiara; Marcelli, A.; Chu, W.; Wu, Z.
abstract
Presentazione orale
2008
- I suoli a mirtillo (Appennino Modenese)
[Relazione in Atti di Convegno]
P., Marchetto; Laurora, Angela; Malferrari, Daniele; Brigatti, Maria Franca; Bosi, Giovanna
abstract
Lo scopo dello studio è di verificare se la crescente diffusione di falso mirtillo nei vaccinieti spontanei del territorio del Frignanp (Alto Appennino modenese) sia correlata con la variazione delle caratteristiche chimico-ficsiche del suolo.
2008
- Interlayer potassium and its neighboring atoms in micas: Crystal chemical modeling and XANES spectroscopy
[Articolo su rivista]
Brigatti, Maria Franca; Malferrari, Daniele; Poppi, M; Mottana, A; Cibin, G; Marcelli, A; Cinque, G.
abstract
The aim of this work is to provide a detailed description of the interlayer site in trioctahedral true micas by combining crystal-chemical and spectroscopic evidence. Insights obtained are based on a statistical appraisal of crystal-chemical, structural and spectroscopic data determined on two sets of trioctahedral micas extensively studied by both X-ray diffraction refinement on single crystals (SC-XRD) and X-ray absorption fine spectroscopy (XAFS) at the potassium K-edge. Spectroscopy was carried out on both random powders and oriented cleavage flakes, the latter setting taking advantage of the polarized character of synchrotron radiation. Such an approach (AXANES) is shown to be complementary to crystal-chemical investigation based on SC-XRD refinement. However, the results are not definitive as they focus on few samples having extreme features only (e.g., end-members, unusual compositions, and samples with extreme and well-identified substitution mechanisms). The experimental absorption K-edge (XANES) was decomposed by calculation and extrapolated into a full in-plane absorption component and a full out-of-plane absorption component. These two patterns reflect different structural features: represents the arrangement of the atoms located in the mica interlayer space and facing tetrahedral sheets; is associated to multiple-scattering interactions entering deep into the mica structure, thus reflecting also interactions with the heavy atoms (essentially Fe) located in the octahedral sheet. The out-of-plane patterns also reflect somewhat the octahedral atoms electronic properties, such as their oxidation states (e.g., Fe2+ and Fe3+) and their ordering (e.g., trans- vs. cis-setting). Distinction between fluoro- and hydrous micas is also possible due to peculiar absorption features originating from the F vs. OH occupancy of the O4 octahedral site. Thus, combining structural and spectroscopic information is shown to be a practical method that allows, on one hand, assigning the observed spectroscopic features to precise structural pathways followed by the photoelectron within the mica structure and, on the other hand, clarifying on the amount of electronic interactions and forces acting onto the individual atoms at the various structural sites.
2008
- Kelvin probe and surface shear microscopy of layer silicates
[Relazione in Atti di Convegno]
Valdrè, G.; Moro, D.; Malferrari, Daniele; Brigatti, Maria Franca
abstract
nd
2008
- Modification of Hg complexes in layered silicates with temperature: an in situ XAS study
[Articolo su rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Marcelli, A; Chu, W; Wu, Z.
abstract
This work will address the thermal evolution (variation in oxidation state, disproportionation reactions) of Hg(II), adsorbed by two different layer silicates (montmorillonite and vermiculite) via XAS spectroscopy at increasing temperature. From the XANES analysis we could recognize significant structural differences between Hg-treated montmorillonite and vermiculite even at room temperature. At increasing temperature Hg is not easily removed from the silicate layer and it could be identified in layer structure up to T = 400 °C in montmorillonite and up to T = 700 °C in vermiculite. Furthermore, it is evident from EXAFS spectra collected at room temperature that Hg–H2O complexes are present in both montmorillonite and vermiculite, whereas the HgO form appears only in vermiculite.
2008
- Single-crystal X-ray studies of trioctahedral micas coexisting with dioctahedral micas in metamorphic sequences from Western Maine
[Articolo su rivista]
Brigatti, Maria Franca; Guidotti, Cv; Malferrari, Daniele; Sassi, Fp
abstract
A crystal chemical study of thirteen biotite (twelve of 1M polytype and one of 2M1 polytype) and four muscovite samples were made. The biotite, coexists with the muscovite. Samples are from metamorphic terrains and from granitic and granodioritic bodies occurring in three areas of western Maine. The metamorphic mineral zones identified by mineral compatibilities are, for increasing metamorphic grade, the Lower Sillimanite Zone (LSZ), the Upper Sillimanite Zone (USZ) and the K-feldspar + Sillimanite Zone (K+SZ). The muscovite composition clusters near ideal muscovite and displays a small celadonite substitution and a small, but variable paragonite substitution. The biotite composition displays a ratio [vi]Mg2+ / [vi](Mg2+ + Fe2+) ranging from 0.26 to 0.54 and significant octahedral Al content from 0.48 to 0.72 apfu in metamorphic biotite samples and from 0.51 to 0.67 in those from granites).In trioctahedral micas from western Maine and especially in those with graphite, there is a greater number of interlayer vacancies than in common micas. Interlayer vacancies have an increase in interlayer cation – basal oxygen atom distances and a decrease in tetrahedral flattening angle tau, thus suggesting a reduced interlayer charge. With a few exceptions, tetrahedral rotation angle alpha is related to crystallization temperature. In particular alpha decreases with a temperature increase, and alpha is also related to octahedral chemical substitutions. Results tentatively suggest, for micas from metamorphic environments, a direct influence of genetic parameters (T and fO2) on mica crystal structure, and not just chemical composition.
2008
- The octahedral anionic site in micas: a comparison between fluorannite and annite
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Caprilli, Enrico; Malferrari, Daniele; Mottana, A.
abstract
nd
2008
- X-ray microdiffraction as a tool for single crystal structure refinement: a study on apatite crystals
[Relazione in Atti di Convegno]
Medici, L.; Brigatti, Maria Franca; Malferrari, Daniele
abstract
Poster
2007
- Crystal chemical modeling and XANES spectroscopy of K in interlayer site of micas
[Abstract in Rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Poppi, Marco; Mottana, A.; Cibin, G.; Marcelli, A.; Cinque, G.
abstract
A detailed description of the interlayer site in trioctahedral true micas is presented based on a statistical appraisal of crystal-chemical, structural, and spectroscopic data determined on two sets of trioctahedral micas extensively studied by both X-ray diffraction refinement on single crystals (SC-XRD) and X-ray absorption fine spectroscopy (XAFS) at the potassium K-edge. Spectroscopy was carried out on both random powders and oriented cleavage flakes, the latter setting taking advantage of the polarized character of synchrotron radiation. Such an approach (AXANES) is shown to be complementary to crystal-chemical investigation based on SC-XRD refinement. However, the results are not definitive as they focus on few samples having extreme features only (e.g., end-members, unusual compositions, and samples with extreme and well-identified substitution mechanisms). The experimental absorption K-edge (XANES) for potassium was decomposed by calculation and extrapolated into a full in-plane absorption component (sigma (sub ) ) and a full out-of-plane absorption component (sigma ). These two patterns reflect different structural features: sigma (sub ) represents the arrangement of the atoms located in the mica interlayer space and facing tetrahedral sheets; sigma is associated with multiple-scattering interactions entering deep into the mica structure, thus also reflecting interactions with the heavy atoms (essentially Fe) located in the octahedral sheet. The out-of-plane patterns also provide insights into the electronic properties of the octahedral cations, such as their oxidation states (e.g., Fe (super 2+) and Fe (super 3+) ) and their ordering (e.g., trans- vs. cis-setting). It is also possible to distinguish between F- and OH-rich micas due to peculiar absorption features originating from the F vs. OH occupancy of the O4 octahedral site. Thus, combining crystal-chemical, structural, and spectroscopic information is shown to be a practical method that allows, on one hand, assignment of the observed spectroscopic features to precise structural pathways followed by the photoelectron within the mica structure and, on the other hand, clarification of the amount of electronic interactions and forces acting onto the individual atoms at the various structural sites.
2007
- Crystal chemical modeling and XANES spectroscopy of the potassium interlayer in micas
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Malferrari, Daniele; Poppi, M.; Mottana, A.; Cibin, G.; Marcelli, A.; Cinque, G.
abstract
nd
2007
- Crystal chemistry of trioctahedral micas in alkaline and subalkaline volcanic rocks: A case study from Mt. Sassetto (Tolfa district, Latium, central Italy)
[Articolo su rivista]
Laurora, Angela; Brigatti, Maria Franca; Mottana, A.; Malferrari, Daniele; Caprilli, Enrico
abstract
This work provides a crystal-chemical description of trioctahedral micas from volcanic rocks (lavas, tuffs, ignimbrites, and xenoliths) outcropping at Mt. Sassetto (Tolfa district, Tuscan Province, central Italy). Mica crystals vary in composition from ferroan phlogopite to magnesian annite. Heterovalent octahedral substitutions are mainly related to Al3+, Ti4+, and, only in a few samples, to Fe3+. The two main mechanisms regulating Ti inlet into the mica structure are the Ti-oxy [Ti-VI(4+VI)(Mg,Fe)(-1)(2+)(OH)(-2)O--(2)2-] and Ti-vacancy [Ti-VI(4+VI)rectangle(VI)(Mg,Fe)(-2)(2+)] substitutions. In these micas, Ti content is the predominant crystal-chemical parameter and significantly affects octahedral and interlayer topology as well. Micas with the highest Ti contents deviate from the expected fractional crystallization trend in the Ti vs. Mg/(Mg + Fe-tot) diagram, possibly as a consequence of a variation in intensive parameters (T, P, f(H2),f(O2),f(H2O)) during crystallization in the magmatic chamber. In micas with significant Fe3+ contents, the layer charge balance is accomplished by the following mechanisms: (Fe-32+VIFe23+VI)-Fe-VI rectangle, (Fe-12+VIFe3+)-Fe-VI(OH)(-)O--(2-), and (Fe-12+VIFe3+IVSi-14+IVAl3+)-Fe-Vi. These micas show mean electron counts greater for the octahedral M2 site than for M1, and unit-cell parameters significantly smaller than usual for other micas. Atmospheric weathering is unlikely to produce the observed Fe oxidation. The Fe3+-vacancy and Fe-oxy substitutions could represent secondary, re-equilibration effects related to post-eruptive water-rock hydrothermal processes (acid-sulfate alteration).
2007
- Crystal structure and chemical composition of Li-, Fe-, and Mn-rich micas
[Articolo su rivista]
Brigatti, Maria Franca; Mottana, A; Malferrari, Daniele; Cibin, G.
abstract
We present in this paper the crystal chemical characterization of three (Fe, Mn)-rich lithian trioctahedral micas. The samples are from Hirukawa mine (Japan) (unit formula: [iv](Si3.425Al0.575)4.00[vi](Al1.002Ti0.002Cr0.001Fe0.379Mg0.005Mn0.173Li1.438)3.00 [xii](Ca0.002Ba0.001Na0.049K0.948Rb0.002)1.00 O10F2 ; unit-cell dimensions: a = 5.264(1), b = 9.086(2), c = 10.099(3) Å, β = 100.719(5)°, V = 474.6(2) Å3); from Mokrusha mine (Russia) (unit formula: [iv](Si3.304Al0.696)4.00 [vi](Al1.004Ti0.001Fe0.362Mg0.005 Mn0.306Li1.322)3.00 [xii](Ca0.012Ba0.001Na0.042K0.940Rb0.005)1.00 O10F2; unit-cell dimensions: a = 5.297(5), b = 9.133(7), c = 10.168(9) Å, β = 100.78(2)°, V = 483.2(7) Å3); and from Sawtooth Mountains (Boise County, Idaho, U.S.A.) (unit formula: [iv](Si3.105Al0.895)4.00 [vi](Al0.913Ti0.018 Fe0.456Mg0.031 Mn0.521Li1.061)3.00 [xii](Ca0.004Ba0.003Na0.048K0.924Rb0.021)1.00 O10F2; unit-cell dimensions a = 5.2984(3), b = 9.1461(6), c = 10.0966(7) Å, β = 100.818(4)°, V = 480.58(5) Å3). All crystals belong to 1M polytype with layer symmetry C12(1) and show M1 and M3 sites much greater than M2. Moreover mean electron count values are much more variable for M1 and M3 sites than for M2. Unlike sample from Sawtooth Mountains, tetrahedral mean bond lengths appear to be smaller for T1 than for T11 site in Hirukawa mine and in Mokrusha mine.When compared to samples from the zinnwaldite series, crystals under study show similar crystal chemical trends, thus hinting to similar effects produced on layer structure by Fe and Mn cations.
2007
- Crystal structure and crystal chemistry of fluorannite and its relationships to annite
[Articolo su rivista]
Brigatti, Maria Franca; Caprilli, Enrico; Malferrari, Daniele; Mottana, A.
abstract
This contribution deals about the crystal chemical characterization of fluorannite from Katugin Ta-Nb deposit, Chitinskaya Oblast’, Kalar Range, Transbaikalia, Eastern-Siberian Region, Russia. The mineral chemical formula is (K0.960Na0.020Ba0.001) (Fe2+2.102Fe3+0.425Cr3+0.002Mg0.039Li0.085Ti0.210Mn0.057) (Al0.674 Si3.326) O10 (F1.060OH0.028O0.912). This mica belongs to 1M polytype (space group C2/m) with layer parameters a = 5.3454(2) Å, b = 9.2607(4) Å, c = 10.2040(5) Å, beta = 100.169(3)°. Structure refinement, using anisotropic displacement parameters, converged at R = 0.0384. When compared to annite, fluorannite shows a smaller cell volume (Vfluorannite = 497.19 Å3; Vannite = 505.71 Å3), because of its smaller lateral dimensions and its reduced c parameter. The flattening of the tetrahedral basal oxygen atoms plane decreases with F content, together with the A-O4 distance (i.e., the distance between interlayer A cation and the octahedral anionic position) because of the reduced repulsion between the interlayer cation and the anion sited in O4.
2007
- Il mirtillo nero del Frignano: risorsa da conoscere, valorizzare e difendere
[Altro]
Brigatti, Maria Franca; Malferrari, Daniele
abstract
Convegno tenutosi a Pavullo nel Frignano (Modena, Italy) il 25 maggio 2007.
2007
- Interlayer potassium and its surrounding in micas: Crystal chemical modeling and XANES spectroscopy
[Abstract in Rivista]
Brigatti, Maria Franca; Malferrari, Daniele; Poppi, M.; Mottana, A.; Cibin, G.; Marcelli, A.; Cinque, G.
abstract
Crystal chemistry and topology of the interlayer cations in micas were detailed by several authors and readily appeared not only to be sensitive to the interlayer composition, but to mirror also the topology of other sites occurring in the mica structure (i.e., tetrahedral, octahedral and anionic sites). The aim of this work is to provide a detailed description of the interlayer site in trioctahedral true micas by combining crystal-chemical and spectroscopic evidence. Insights obtained are based on a statistical appraisal of crystal-chemical, structural and spectroscopic data determined on two sets of trioctahedral micas extensively studied by both X-ray diffraction refinement on single crystals (SC-XRD) and X-ray absorption fine spectroscopy (XAFS) at the potassium K-edge. Spectroscopy was carried out on both random powders and oriented cleavage flakes, the latter setting taking advantage of the polarized character of synchrotron radiation. Such an approach (AXANES) is shown to be complementary to crystal-chemical investigation based on SC-XRD refinement. However, the results are not definitive as they focus on few samples having extreme features only (e.g., end-members, unusual compositions, and samples with extreme and well identified substitution mechanisms). The experimental absorption K-edge (XANES) was decomposed by calculation and extrapolated into a full in-plane absorption component (||) and a full out-of-plane absorption component (?). These two patterns reflect different structural features: || represents the arrangement of the atoms located in the mica interlayer space and facing tetrahedral sheets; ? is associated to multiplescattering interactions entering deep into the mica structure, thus reflecting also interactions with the heavy atoms (essentially Fe) located in the octahedral sheet. The out-of-plane pattern also reflects somewhat the octahedral atoms electronic properties, such as their oxidation states (e.g., Fe2+ and Fe3+) and their ordering (e.g., trans- vs. cis-setting). Distinction between fluoro- and hydrous micas is also possible due to peculiar absorption features originating from the F vs. OH occupancy of the O4 octahedral site. Thus, combining structural and spectroscopic information is shown to be a practical method that allows, on one hand, assigning the observed spectroscopic features to precise structural pathways followed by the photoelectron within the mica structure and, on the other hand, clarifying on the amount of electronic interactions and forces acting onto the individual atoms at the various structural sites.
2007
- Polluted sediments from canals for water supplying and drainege: treatment and recycle
[Abstract in Rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Laurora, Angela; Pini, Stefano; Pistoni, Roberto
abstract
One of the most critical aspects of the maintenance of canals for water supplying and drainage is the managing of deposited sediments, which must be periodically removed. Deposited sediments, if containing anthropogenic pollutants with a concentration exceeding specific law limits, must be stored as industrial wastes, thus raising additional economic and logistic problems to deal with. Our research considers polluted sediments from an area close to the south side of Po river, in order to characterize heavy metals associated with different mineral species, thus defining effective treatments for their inertization, and suggesting a possible process for their recycle. Our results demonstrate that the composition of these sediments is suitable for the production of tiles and bricks. Several tests were thus performed to optimize sample treatment and other process parameters, finally giving very encouraging results. Releasing tests on fired products reveal that all the heavy metals are well retained.
2007
- Pollution of recent sediments from canals for water supplying and drainage
[Relazione in Atti di Convegno]
Malferrari, Daniele; Brigatti, Maria Franca; Laurora, Angela; Pini, Stefano; Pistoni, Roberto
abstract
nd
2007
- Recupero e valorizzazione di sedimenti estratti da canali di bonifica ed approvvigionamento idrico mediante inertizzazione termica.
[Relazione in Atti di Convegno]
Pistoni, Roberto; Malferrari, Daniele; Brigatti, Maria Franca; Pini, Stefano; Tonelli, F.
abstract
nd
2007
- Sedimenti provenienti dai canali di bonifica: valutazione del potenziale impatto ambientale.
[Relazione in Atti di Convegno]
Malferrari, Daniele; Borghi, V.; Brigatti, Maria Franca; Laurora, Angela; Mantovani, E.; Pistoni, Roberto
abstract
nd
2007
- Sorption kinetics and chemical forms of Cd(II) sorbed by thiol-functionalized 2:1 clay minerals
[Articolo su rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Laurora, Angela; Pini, Stefano; Medici, L.
abstract
The interaction between Cd(II) in aqueous solution and two 2:1 expandable clay minerals (i,e., montmorillonite and vermiculite), showing different layer charge, was addressed via batch sorption experiments on powdered clay minerals both untreated and amino-acid (cysteine) treated. Reaction products were characterized via X-ray diffraction, chemical analysis (Elemental Analysis and Atomic Absorption Spectrophotometry), thermal analysis, mass spectrometry and synchrotron-based X-ray absorption spectroscopy (XAS) techniques. Namely, the uptake of Cd(II) from each adsorbent was measured by analyzing, via atomic absorption spectroscopy, the liquid portion separated after centrifugation following a controlled period of exposure. The main outcome was thus the definition of the sorption behavior of Cd(II) as a function of the features of the substrates (e.g. different layer charge, presence or not of the amino acid cysteine). Thermal decomposition of Cd-cysteine treated clay minerals evidences the evolution of H2O, H2S, NO2, SO2, and N2O3. EXAFS studies suggest that Cd(II) coordinates with oxygen atoms, to give monomer complexes or CdO molecules, either on the mineral surface and/or in the interlayer. For Cd-cysteine complexes XAS data agree with the existence of Cd-S clusters, thus suggesting a predominant role of the thiol group in the bonding of Cd with the amino acid.
2007
- The effect of different plasma gas environments on vermiculite layer
[Articolo su rivista]
Valdre, G; Malferrari, Daniele; Marchetti, Diego; Brigatti, Maria Franca
abstract
This work presents the first results of a broader research project aimed at the development or modifications of clays with increased properties for technological purposes and novel applications. This first step addresses on the chemical and physical properties of vermiculite treated with several ionised gasses in controlled plasma environments. Vermiculite is a 2:1 layered silicate with well-known chemical-exchange and surface properties useful in many industrial applications. The improving of these properties, in particular at the nanoscale level, can in principle enhance its application in known technological fields and extend its use in novel research and applicative areas as well as in nanotechnology. Vermiculite was treated with argon, air, water vapour and hydrogen radio frequency plasmas at room temperature for few minutes. As a general rule, plasma gasses induced various layer modifications. Chemical analyses evidenced a significant decrease in the interlayer cation content, especially for hydrogen and water vapour treated specimens. X-ray diffraction showed both a decrease of peak intensity and a halving of (001) reflection, thus suggesting the formation of layer defects along the layer stacking direction and onto (001) planes as well. Thermal analysis showed modifications of the temperature-activated reactions induced by the plasma treatments. Finally Fourier Transformed Infra-Red spectroscopy (FTIR) showed that different bonding of H2O occurred after the treatment, in particular for vermiculite treated with hydrogen plasma. (c) 2006 Elsevier B.V. All rights reserved.
2007
- Valutazione dello stato ambientale delle ex aree minerarie a solfuri di Boccassuolo (Palagano, Modena) e Cà Marsilio e Cà Gabriele (Montecreto, Modena)
[Articolo su rivista]
Brigatti, Maria Franca; Galli, Ermanno; Malferrari, Daniele; Rossi, Antonio
abstract
Negli ultimi decenni l'ambiente ipogeo artificiale ha attirato l'attenzione di numerosi speleologi e di studiosi che, attraverso ricerche a carattere multidisciplinare, hanno evidenziato non solo il particolare significato storico, religioso e culturale di tali siti, ma anche la loro importanza quali strutture attraverso le quali, ad esempio, è awenuto il rifornimento idrico di grandi città e come opere realizzate dall'uomo anche in tempi recenti per coltivare giacimenti di materie prime utili alla sua quotidianità. In quest'ultimo caso si tratta delle numerose gallerie di miniera quasi tutte ormai abbandonate, ma che in parte, se almeno recuperate e rese sicure ed agibili, possono rappresentare una non trascurabile attrazione turistica e locale fonte di lavoro. Per alcune di queste realtà talora è sorta la preoccupazione della possibilità che le acque da esse derivate o le loroaree di discarica esterne rappresentassero agenti di potenziali inquinanti di territori (ambienti) circostantida parte di elementi tossici (pericolosi) presenti nelle mineralizzazioni coltivate.In relazione a questo problema, in questa nota vengono presentati i risultati di analisi relative adalcuni possibili agenti inquinanti naturali, effettuate su campioni di terreni e vegetali, raccolti nell'intornodelle due uniche zone minerarie a solfuri della provincia di Modena. In particolare è statavalutata la concentrazione di metalli pesanti (Cu, Zn e Pb) in sedimenti e licheni campionati nell'areacircostante il complesso minerario. È stata inoltre valutata la speciazione chimica di questi elementi combinando differenti tecniche analitiche. I risultati ottenuti indicano che l'inquinamentodella zona non raggiunge valori significativamente pericolosi e che gli attuali livelli sono comparabilia quelli determinati dalla stessa presenza del complesso minerario (inquinamento naturale)
2006
- Crystal chemistry of some trioctahedral and dioctahedral micas coexisting in metamorphic sequences from N.W. Maine
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Guidotti, C. V.; Malferrari, Daniele; Sassi, F. P.
abstract
nd
2006
- High temperature XAS study D. of Hg and Hg-cysteine complexes in montmorillonite and vermiculite
[Relazione in Atti di Convegno]
Malferrari, Daniele; Brigatti, Maria Franca; Z. Y., Wu; W. H., Liu; G., Cibin; A., Marcelli
abstract
nd
2006
- Interlayer material and its surrounding in micas: crystal chemical modeling and XANES spectroscopy
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Cibin, G.; Cinque, G.; Malferrari, Daniele; Marcelli, A.; Mottana, A.; Pini, Stefano; Poppi, Marco
abstract
nd
2006
- Soils under bilberry in the Frignano area (Modena Apennine)
[Articolo su rivista]
Marchetto, Patrizia; Laurora, Angela; Malferrari, Daniele; Brigatti, Maria Franca; Bosi, Giovanna
abstract
nd
2006
- Structure of Hg complexes in layer silicates: XAS and XRDP high temperature investigation
[Relazione in Atti di Convegno]
Malferrari, Daniele; Brigatti, Maria Franca; Cibin, G.; Liu, W. H.; Marcelli, A.; Wu, Z. Y.
abstract
nd
2006
- The effect of different plasma gas environments on vermiculite layer
[Relazione in Atti di Convegno]
Valdrè, G.; Malferrari, Daniele; Marchetti, Diego; Brigatti, Maria Franca
abstract
nd
2006
- Thermal behavior of Cu(II)-, Cd(II)-, and Hg(II)-exchanged montmorillonite complexedwith cysteine
[Articolo su rivista]
Malferrari, Daniele; Brigatti, Maria Franca; Laurora, Angela; Medici, L; Pini, Stefano
abstract
The thermal behavior of montmorillonite and organically modified montmorillonite, both treated with heavy metal cations [Cu(II), Cd(II) and Hg(II)], was characterized via thermal analyses (TG, DTG and DTA) combined with evolved species gas mass spectrometry (MS-EGA), and X-ray diffraction at in situ controlled temperature (HTXRD). The reactions involving Cu(II)-and Cd(II)-montmorillonite samples are mostly related to H2O and OH loss, unlike Hg(II)-montmorillonite, where effects associated to Hg(II) loss are also present. Finally reactions related to dehydration, dehydroxylation and to organic matter decomposition can be observed in montmorillonite samples treated with cysteine.
2005
- Adsorption of [Al(Urea)(6)](3+) and [Cr(Urea)(6)](3+) complexes in the vermiculite interlayer
[Articolo su rivista]
Brigatti, Maria Franca; Laurora, Angela; Malferrari, Daniele; Medici, Luca; Poppi, Luciano
abstract
This work investigates the interaction between vermiculite and urea metal complexes {[Cr(Urea)(6)](3+) and [AI(Urea)(6)](3+)} via several techniques, including: i) chemical analyses; ii) X-ray diffraction at controlled temperature; iii) microdiffraction on selected crystal areas; iv) thermal analyses and mass spectrometry of evolved species during heating; v) atomic force microscopy; vi) micro-FTIR. Organo-clay complexes were prepared both at room (25 C) and 60 degrees C temperature. Vermiculite treated with [Al(Urea)(6)](3+) showed a complete adsorption of the complex at room temperature, unlike vermiculite treated with [Cr(Urea)(6)](3+) where only a partial exchange was observed. The X-ray investigation evidenced disordered sequences in the layer stacking as common in vermiculite treated with [Al(Urea)6](3+) and [Cr(Urea)(6)](3+) at 60 degrees C. Stacking disorder is present also at room temperature when complexed with [Cr(Urea)(6)](3+) solutions. Microdiffraction investigation identified several domains in vermiculite treated at 60 degrees C. This evidence is also reinforced by FTIR spectroscopy data, which revealed the presence of ammonium isocyanate.
2005
- Crystal Chemical Models on Trioctahedral and Dioctahedral Micas
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Guggenheim, S.; Laurora, Angela; Malferrari, Daniele; Poppi, M.; Poppi, Luciano
abstract
nd
2005
- Crystal Structure and Chemistry of trilithionite-2M2 and polylithionite-2M2
[Articolo su rivista]
Brigatti, Maria Franca; Caprilli, Enrico; Malferrari, Daniele; Medici, Luca; Poppi, Luciano
abstract
The crystal chemistry of three Li-bearing mica-2M(2) crystals from pegmatites has been studied by chemical analyses and single crystal X-ray diffraction; their belonging to the trilithionite-polylithionite join is highlighted by the following compositional ranges in atoms per formula unit [based on O12-(x+y) (OH)(x)F-y] : 3.198 <= Si <= 3.538, 0.462 <= [IV]Al <= 0.811, 1.195 <= [IV]Al <= 1.390, 0.031 <= (Fe+Mn) <= 0.072, 1.522 <= Li <= 1.757, 0.872 <= K <= 0.906, 0.030 <= Na <= 0.073, 0.000 <= (Cs+Rb) <= 0.099, 1.541 F <= 1.722. The correlation between F and Li content is confirmed, as observed in Li-rich micas. Crystal structure refinements were carried out in space group C2/c (R values vary between 0.030 and 0.03 1). The crystal chemistry is mostly influenced by tetrahedral chemical composition. Increasing [IV]Al content, cc and psi(MI) parameters increase; Si content involves a lowering of the interlayer separation and tetrahedral thickness. Li content affects octahedral thickness. The stability of 2M(2) polytype seems to be induced by a relative increase of Delta z tetrahedral parameter, which reduces the repulsion between basal tetrahedral oxygen atoms. Unlike Li-bearing muscovite, trioctabedral Li-bearing mica crystals show an octahedral occupancy not related to octahedral charge.
2005
- Interactions of Mica and Vermiculite Layers with Ionized Gasses
[Relazione in Atti di Convegno]
Marchetti, Diego; Brigatti, Maria Franca; Laurora, Angela; Malferrari, Daniele; Valdré, G.
abstract
nd
2005
- Mercury adsorption by montmorillonite and vermiculite: a combined XRD, TG-MS, and EXAFS study.
[Articolo su rivista]
Brigatti, Maria Franca; Colonna, S.; Malferrari, Daniele; Medici, Luca; Poppi, Luciano
abstract
Synchrotron based extended X-ray absorption fine structure spectroscopy (EXAFS), X-ray diffraction at room and high temperature, thermal analyses combined with mass spectrometry of evolved gas, and chemical analyses contributed to assess the influence of mercury on montmorillonite and vermiculite layers. The adsorbed Hg amount was higher for montmorillonite (Hg = 37.7 meq/100g) than for vermiculite (Hg = 28.0 meq/100g). The basal spacing for the Hg treated samples was 15.2 (montmorillonite) and 14.5 Å (vermiculite). Thermal and evolved gas spectrometry analyses suggest that Hg was released at T 230°C and at 600°C for montmorillonite, but at 550, 800 and 860°C for vermiculite. The effect of temperature on Hg release is also apparent when the basal spacing at 230°C for montmorillonite (d001 = 10.3 Å) is compared to that for vermiculite (d001 = 11.8 Å).EXAFS analyses provide qualitative evidence that oxygen atoms occupy the first coordination shell of Hg in both clay minerals. The best fit between observed and calculated spectra is obtained when montroydite is assumed as a reference model compound
2005
- Modification of Hg-H2O and Hg-cysteine complexes in layered structure with temperature: an X-ray, thermal and XAS study
[Relazione in Atti di Convegno]
Malferrari, Daniele; Brigatti, Maria Franca; Cibin, G.; Marcelli, A.; Chu, W. S.; Wu, Z.
abstract
nd
2005
- Modification of vermiculite surface by ionized gasses
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Laurora, Angela; Malferrari, Daniele; Marchetti, Diego; Valdré, G.
abstract
nd
2005
- Reactions of Cd Ions and Cysteine in Aqueous Solutions with Vermiculite
[Relazione in Atti di Convegno]
Pini, Stefano; Brigatti, Maria Franca; Laurora, Angela; Malferrari, Daniele; Medici, L.
abstract
nd
2005
- Sorption kinetics and chemical forms of Cd(II) sorbed by thiol-functionalized 2:1 clays
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Laurora, Angela; Malferrari, Daniele; Medici, L.; Pini, Stefano
abstract
nd
2005
- Study of natural and ion exchanged montmorillonite by thermal analysis (TGA) and evolved gas mass spectrometry (MSEGA)
[Abstract in Rivista]
Brigatti, Maria Franca; Laurora, Angela; Malferrari, Daniele; S., Pini
abstract
Presentazione a poster nella sessione "GEO06- Mineralogia- Mineralogy" tenutasi a Spoleto il 23 settembre 2005 in occasione di Geoitalia 2005
2005
- The 2M1 Dioctahedral Mica Polytype: A Crystal Chemical Study
[Relazione in Atti di Convegno]
Poppi, M.; Brigatti, Maria Franca; Malferrari, Daniele
abstract
nd
2005
- The 2M1 dioctahedral mica polytype: a crystal chemical study
[Articolo su rivista]
Brigatti, Maria Franca; Malferrari, Daniele; Poppi, Marco; Poppi, Luciano
abstract
The structure of dioctahedral true micas such as muscovite and celadonitic muscovite (2M1 polytype, Space Group C2/c) is mostly affected by variations of the octahedral Al content ([vi]Al). Crystals with greater Mg, Fe substitutions (i.e., celadonitic muscovite) reduce the dimensional difference between the larger trans-oriented M(1) site and smaller cis-oriented M(2) octahedral site. The octahedral anionic position O(4) is displaced from the center of the hexagon, defined by O(31) and O(32) oxygen atoms (i.e., “octahedral hexagon”), both on and off the (001) plane. The distance between interlayer cation A and O(4) is smaller in more substituted species, thus providing different orientations of the O(4)-H vector, as a function of [vi]Al. Octahedral distances and are expressed as a function of cell parameters and [vi]Al content, thus allowing an approximate estimate of site dimensions. These approximations are useful when a detailed structural refinement is not available. In celadonitic muscovite, the octahedral hexagon mean edge is not significantly affected by [vi]Al content. The [vi]Al increase produces both a decrease in cell lateral dimensions and a distorted “octahedral hexagon”. The decrease in a and b is consistent with a decrease of , whereas the distortion of the “octahedral hexagon” is consistent with an increase of , because an irregular hexagon produces a longer mean edge than a regular hexagon of equal area.The tetrahedral mean basal edge is reduced as celadonitic substitution progresses. The tetrahedral rotation angle was thus found to increase from celadonite to muscovite. However in muscovite with [vi]Al content between 1.8 and 2.0 atoms per formula unit (apfu), approaches a saturation value, thus showing a proportional increase of tetrahedral and octahedral sheet lateral dimensions. Furthermore, alpha variation allows a coarse approximation of the threshold [vi]Al content, below which celadonitic substitution may not progress.
2005
- Trilithionite-2M2 and Polylithionite-2M2: a Crystal Chemical Study
[Relazione in Atti di Convegno]
Medici, L.; Brigatti, Maria Franca; Caprilli, Enrico; Malferrari, Daniele
abstract
nd
2005
- Trioctahedral and Dioctahedral Micas Coexisting in Metamorphic Sequences from Maine
[Relazione in Atti di Convegno]
Malferrari, Daniele; Benincasa, E.; Brigatti, Maria Franca; Guidotti, C. V.
abstract
nd
2005
- Trioctahedral micas in volcanic rocks from Mt. Sassetto (Tolfa area, Central Italy)
[Abstract in Rivista]
Brigatti, Maria Franca; Caprilli, Enrico; Laurora, Angela; Malferrari, Daniele; L., Medici; A., Mottana
abstract
Presentazione a poster nella sessione "GEO06- Mineralogia- Mineralogy" tenutasi a Spoleto il 23 settembre 2005 in occasione di Geoitalia 2005
2005
- XANES study of Hg sorption products on montmorillonite at high temperatures
[Articolo su rivista]
Chu, W. S.; Wu, Z. Y.; Liu, W. H.; Malferrari, Daniele; Brigatti, Maria Franca; Cibin, G.; Marcelli, A.
abstract
The Hg L3-edge XANES spectra of montmorillonite treated with Hg(NO3)2 0.01M aqueous solution and the mixing solution of Hg(NO3)2 0.01M aqueous solution and cysteine 0.01M aqueous solution have been measured at several high temperatures. The adsorption and desorption of mercury in Hg-rich montmorillonite minerals and the effect of cysteine on the adsorption of mercury by this clay mineral were studied. Our analysis shows that mercury is six fold coordinated by water molecules and the oxygen atoms of montmorillonite surface without the amino acid introduction. Mercury atoms prefer to bond with sulphur atoms of the amino acid cysteine to form more stable Hg-S bonds when the amino acid cysteine has been introduced. This result suggests that the treatment with the amino acid enhances the stability of mercury sorbed by the montmorillonite mineral and efficiently retard the release of mercury ions into the geosphere.
2004
- Characterization of Cu-complexes in smectite with different layer charge location: Chemical, thermal and EXAFS studies
[Articolo su rivista]
Brigatti, Maria Franca; S., Colonna; Malferrari, Daniele; L., Medici
abstract
The retention of Cu and Cu-amino acid complexes by montmorillonite and beidellite, before and after repeated acidified aqueous solution treatments, was studied using X-ray diffraction, chemical and thermal analyses, mass spectrometry and synchrotron-based X-ray absorption spectroscopy (XAS). The results indicate that the extraction of metal complexes from smectites depends on the nature of the layer charge and on the kind of organic species. Cu-cysteine complexes are strongly retained in the interlayer position, whereas Cu-glycine complexes are mostly adsorbed in cationic form which can be easily removed from the silicate layer. The layer periodicity for Cu-smectites treated with glycine shows little or no layer expansion, whereas significant swelling of the layer periodicity is observed in smectites treated with cysteine. Thermal decomposition of both smectites with sorbed Cu-amino acid species shows the evolution of H2O, NO, CH3CH3, and CO2. In Cu-cysteine treated smectites, the release of H2S, NO2, SO2, and N2O3 also occurs. X-ray absorption spectroscopy (XAS) was used to assess the relationships between the structure of the Cu complexes and their desorption from smectites. In Cu-exchanged smectites, the first coordination shell agrees with the hypothesis that the Cu coordinates to oxygen atoms to form monomer and/or dimer complexes. The first coordination shell of Cu in smectites treated with glycine shows four atoms at distances of similar to2 Angstrom. Two of these bonds are with nitrogen and two with oxygen atoms. For copper-cysteine complexes XAS data are compatible with the existence of Cu-N clusters, thus suggesting that Cu links to the amino acid by the aminic group. Copyright
2004
- Crystal Chemistry of Apatite Coexisting With Phlogopite and Tetra-Ferryphlogopite
[Abstract in Rivista]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Ottolini, L.; Poppi, Luciano
abstract
nd
2004
- Crystal Chemistry of Apatites from the Tapira carbonatite complex, Brazil
[Articolo su rivista]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, Luca; Ottolini, L.; Poppi, Luciano
abstract
The crystal chemistry of ten hydroxyl fluorapatite crystals from the Tapira alkaline carbonatitic complex (Brazil) was investigated by electron microprobe, ion microprobe, infrared spectroscopy and single crystal X-ray diffraction. Apatite crystals are characterized by modest REE and a very low Cl content. They exhibit the following compositional range in atoms per formula unit was determined to be 9.935 Ca 10.024, 5.926 P 6.006, 0.005 REE 0.046, 0.422 F 0.914, 0.003 Cl 0.008, 0.003 Si 0.038; Na is present in trace.Crystal structure refinements were carried out in space group P63/m, (R values varies between 0.016 and 0.028). The REE for Ca substitution requires two different exchange mechanisms producing an increase in the bond valence on the X anionic site: the deprotonation of OH and/or the substitution of for OH. The substitution in the anionic sites of investigated structures was related to great CO2 activity of the melt whereas deprotonation of the apatite crystals could be related to the highly oxidizing nature of the Tapira carbonatitic magma. The very low Cl/F ratio suggests that the crystallization of Tapira pluton was relatively shallow. The determination of REE partitioning between the Ca1 and Ca2 sites is difficult because of the low REE content. A proportional increase in the size of the Ca1 and Ca2 sites was observed with increasing REE content as well as an overall increase of a parameter
2004
- “Cu, Cd, Hg and Cu-, Cd-, Hg-cysteine treated montmorillonite and vermiculite crystals: an EXAFS study.
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2003
- Al(urea)63+ and Cr(urea)63+ interactions with vermiculite
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Dilillo, M.; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2003
- An EXAFS study on smectites exchanged with organo-metallic complexes
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2003
- Different organo-metallic species following to Hg, Cu and cysteine treatment on montmorillonite
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Colonna, S.; Malferrari, Daniele; Medici, L.
abstract
nd
2003
- EXAFS analysis of montmorillonite and beidellite intercalated with Cu-amino acid complexes: modelling and experiments
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2003
- Effect of amino acids on the retention of copper by beidellite
[Articolo su rivista]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
The evaluation of environmental hazards related to Cu in urban and industrial run-off, as well as the introduction of possible technologies for the remediation of environmentally compromised areas should not be dealt independently form a sound understanding of structural features of the different interacting species. Low cost clay-minerals are potentially very promising materials for effectively exchanging and stoking Cu. A low cost beidellite was thus evaluated. The mineral behavior in accomplish its function is completely different for the natural and for amino acid complexed sample, with a major influence of the amino acid itself. Different experimental techniques were thus introduced: namely chemical, X-ray diffraction, thermal, mass spectrometry and X-ray absorption spectroscopy analyses. All the knowledge thus acquired on natural and treated species was thus finally related to their adsorption and retention capacity.
2003
- Hg - cysteine complex sorbed by smectites - a combined XRD, TG-MS, and EXAFS study
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2003
- Organo-Metallic Complexes and Phyllosilicate
[Articolo su rivista]
Malferrari, Daniele
abstract
The interaction between Cu exchanged smectites with different layer charge minerals and alpha amino acids glycine and cysteine were studied. A wide variety of analytical techniques were employed namely chemical analyses on solution and mineral, X ray diffraction at room temperature and in the temperature range between 25 and 400 °C, thermal analyses and evolved gasses mass spectrometry.The results suggest that: i) the amount of metal sorbed depends on pH and concentration of solution; ii) organo-metallic complexes are formed in the interalyer region and variations in the Cu local environment occur following treatments with amino acid solution.
2003
- Structural and chemical modification induced in rectorite treated with Hg(II), Cd(II) and cysteine
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2003
- Structural and chemical modifications of natural vermiculite samples induced by the treatment with Al(urea)63+ and Cr(urea)63+ complexes
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Dilillo, M.; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2002
- Characterization of Cu-complexes in smectite with different layer charge location: chemical, thermal and EXAFS study
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2002
- Hg-Cysteine complexes in montmorillonite interlayer
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2002
- I minerali di Monte Cengio
[Articolo su rivista]
Saccardo, D.; Benincasa, E.; Malferrari, Daniele; Medici, L.
abstract
Sono descritti mineralicampionati in un filoncello a solfuri presso Monte Cengio (Vicenza) Le caratterizzazioni sono avvenute per via ottica e diffrattometrica. Tra i minerali riconosciuti sono presenti: adamite, anglesite, auricalcite, azzurrite, barite, beudanite, brochanite, calcite, cerussite, calcopirite, clinotirolite, cuprite, emimorfite, galena, idroncite, langite, malachite, mimetite, parnauite, pirite, quarzo, ramsbeckite, smithsonite sfalerite stolzite, tennantite, wulfenite.
2002
- Metal-organic Cu complexes in smectites with different layer charge location: chemical, thermal and EXAFS study
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Colonna, S.; Malferrari, Daniele; Medici, L.
abstract
nd
2002
- Reactions between Cr(VI) solutions and pyrite: chemical and surface studies
[Articolo su rivista]
Benincasa, E.; Brigatti, Maria Franca; Franchini, Giancarlo; Malferrari, Daniele; Medici, L.; Poppi, Luciano; Tonelli, Massimo
abstract
Geochemical processes that result in the reduction of hexavalent chromium in natural waters with pyrite (FeS2) have been studied at varying degrees of pH (from 1.2 to 12.6) and solution concentration (from 0.001 to 0.3 M of Cr6+) in order to illustrate the differences in the proportions of elements between the aqueous and solid phases and to infer mechanisms that limit the Cr6+ concentration in pore-waters in iron sulfide-rich environments. The experiments were carried out in the absence of oxygen and on pyrite grains previously treated to remove any oxide or sulfur layer at the mineral surface. The methods used to characterize reacting solutions and mineral surface comprised: chemical analyses (microprobe analyses and inductively coupled plasma analyses), scanning electron microscopy, atomic force microscopy and X-ray single crystal analysis. The results suggest that: 1) mineral dissolution increases with decreasing pH, whereas it is close to zero at pH > 7; at alkaline pH, the Cr6+ reduction is very low and the decrease in total Cr probably indicates the formation of precipitated phases, like FeCrO4, on the pyrite surface; 2) Cr6+ reduction is significant at pH < 2.3. Cr6+ to Cr3+ reduction involves the oxidation of Fe2+ and S22- on the pyrite surfaces, following the reaction 2FeS2+5Cr2O72-+32H+2Fe(OH)3 +4(SO4)2- +10Cr3+ +13H2O; 3) at acidic pH all the pyrite crystals show a variable Cr content on the surfaces.
2002
- Reactions of Zn2+ aqueous solutions with fluor-hydroxyapatite: a crystallographic evidence
[Articolo su rivista]
Brigatti, Maria Franca; Benincasa, Emanuele; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
In order to evaluate the possible use of natural fluor-hydroxyapatite (FOHAp) crystals as soil additive for the in situ remediation of heavy-metal contaminated soils, the crystal structure of FOHAp crystals, used in batch experiments at 22°C with pH within the range 4.8-9.5 and in presence of Zn2+ ions, was determined. Crystal structures (space group P63/m) converged to R = 0.026 for untreated FOHAp and to R =0.028 (Experiment 1) and R= 0.032 (Experiment 2) for Zn2+-treated FOHAp crystals. The site occupancy ratios [(Zn-Ca)2/(Zn-Ca)1] obtained from the refinement of electron density is = 1.500 for natural FOHAp, 1.500 (Experiment 1) and 1.520 (Experiment 2) in Zn2+-treated crystals. The value deriving from experiment 2 agrees with small changes in Ca2 site occupancy. Ca2O6X polyhedron distortions may be related both to a slight preference of Zn for Ca2 and to OH for F substitution during the overall reaction sequence.
2002
- Sorption of Cd-cysteine complexes by kaolinite
[Articolo su rivista]
Benincasa, Emanuele; Brigatti, Maria Franca; Malferrari, Daniele; L., Medici; Poppi, Luciano
abstract
The effect of cysteine on the adsorption of Cd(II) by kaolinite was examined at 25 jC using a low-defect kaolinite fromMinas Gerais (Brazil) and a high-defect kaolinite from Berici Hills (Italy). The chemical data demonstrated that the amount ofCd–cysteine detected on kaolinite increases rapidly during the first few hours with a first-order reaction, thereafter adsorptionbecomes linear with time for low-defect kaolinite and slows rapidly for high-defect kaolinite. In low-ordered kaolinite, the Cd–cysteine is intercalated in the structure. Evidence of these changes was also observed by differential thermal analysis (DTA).The thermal decomposition of the Cd–cysteine adsorbed on the kaolinites was studied by analysing the evolved gases. Themass spectra of both samples show the evolution of NO (or CH3CH3, m/z = 30), CO2 (m/z = 44), and SO2 (m/z = 64) between 150 and 300 jC and of H2O (m/z = 18), CO2 (m/z = 44) and SO2 (m/z = 64) in the temperature range between 400 and 700 jC.The high-defect kaolinite also caused the evolution of molecular units with m/z=34 (H2S) and m/z=76 (N2O3). D 2002Elsevier Science B.V. All rights reserved.
2002
- Structural modifications induced by metal complexation with organic matter in smectites: a multi-analytical approach
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Colonna, S.; Malferrari, Daniele; Medici, L.
abstract
nd
2001
- Kinetics of Cd sorption by kaolinite in presence of sulphur-bearing amino acids
[Relazione in Atti di Convegno]
Benincasa, Emanuele; Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2001
- Kinetics of Cr(VI) reduction by Fe(II)-bearing minerals: chemical treatments, X-ray absorption spectroscopy and surface studies.
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Benincasa, Emanuele; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2001
- Reactions of Hg ions in aqueous solutions with smectite in presence of the amino acid cysteine
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Malferrari, Daniele; Poppi, Luciano
abstract
nd
2001
- Reactions of Pb2+ and Zn2+ aqueous solutions with fluorapatite crystals
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Benincasa, Emanuele; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2001
- Structural and chemical modifications of natural vermiculite samples induced by the treatment with Cd-ethylenediamine complex
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Benincasa, Emanuele; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2001
- Structural and chemical modifications of vermiculite crystals induced by Cd-ethylenediamine complex treatment
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Benincasa, Emanuele; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2001
- X-ray absorption spectroscopy of Cu-rich smectites treated with alpha-amino acids
[Relazione in Atti di Convegno]
Brigatti, Maria Franca; Benincasa, Emanuele; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2000
- A regular interstratified mica-smectite mineral from micaschist levels of Sesia Lanzo Zone (Italy)
[Relazione in Atti di Convegno]
Benincasa, Emanuele; Brigatti, Maria Franca; Malferrari, Daniele; M. e. d. i. c. i., L.; Poppi, Luciano
abstract
nd
2000
- Experimental evidence of Hg and Cu retention by montmorillonite: a combined chemical and XAS study
[Abstract in Rivista]
Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2000
- Interaction of pyrite surface with Cr(VI) aqueous solutions
[Abstract in Rivista]
Benincasa, Emanuele; Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano; Vendrame, F.
abstract
nd
2000
- K-rich rectorite from kaolinized micaschists of Sesia-Lanzo zone (Italy)
[Abstract in Rivista]
Benincasa, Emanuele; Brigatti, Maria Franca; Malferrari, Daniele; Medici, L.; Poppi, Luciano
abstract
nd
2000
- XAFS study of Cu sorption products on smectites treated with alpha-amino acids
[Relazione in Atti di Convegno]
Benincasa, Emanuele; Brigatti, Maria Franca; Malferrari, Daniele; Poppi, Luciano
abstract
The interaction between Cu-exchanged smectites with different layer charge, a montmorillonite and a beidellite, and .alpha.-amino acids, glycine and cysteine, was studied. Sequential extn. procedures were carried out in order to test the possibility of removing metals from the mineral structure. Cu sorption is dominated by cation exchange, whereas after the amino acid treatment, Cu-amino acid-smectite complexes occupy the interlayer positions. The formation of a stable chelate complex with .alpha.-amino acids permits Cu to be resistant to migration in soils and groundwaters. X-ray absorption spectroscopy was used to define the local environment of Cu taken up by smectites.