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Pagina personale di Daniele MALFERRARI

Dipartimento di Scienze Chimiche e Geologiche
Dipartimento di Scienze Chimiche e Geologiche - Sede Dipartimento di Scienze Chimiche e Geologiche

Malferrari, Daniele; Castellini, Elena; Bernini, Fabrizio; Serrano Rubio⁠, Aida; Rafael Castro, German; Ignacio Sainz-Díaz⁠, Claro; Caleffi, Matteo; Brigatti, Maria Franca; Borsari, Marco ( 2018 ) - Chemical trapping of gaseous H⁠2S at high and low partial pressures by an iron complex immobilized inside the montmorillonite interlayer - MICROPOROUS AND MESOPOROUS MATERIALS - n. volume 265 - pp. da 8 a 17 ISSN: 1387-1811 [Articolo in rivista (262) - Articolo su rivista]
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.

Iannuccelli, Valentina; Maretti, Eleonora; Bellini, Alessia; Malferrari, Daniele; Ori, Guido; Montorsi, Monia; Bondi, Moreno; Truzzi, Eleonora; Leo, Eliana Grazia ( 2018 ) - Organo-modified bentonite for gentamicin topical application: interlayer structure and in vivo skin permeation - APPLIED CLAY SCIENCE - n. volume 158 - pp. da 158 a 168 ISSN: 0169-1317 [Articolo in rivista (262) - Articolo su rivista]
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.

Castellini, Elena; Malferrari, Daniele; Bernini, Fabrizio; Brigatti, Maria Franca; Castro, German Rafael; Medici, Luca; Mucci, Adele; Borsari, Marco ( 2017 ) - Baseline studies of The Clay Minerals Society Source Clay montmorillonite STx-1b - CLAYS AND CLAY MINERALS - pp. da 220 a 233 ISSN: 0009-8604 [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti, Maria Franca; Díaz, Claro Ignacio Sainz; Borsari, Marco; Bernini, Fabrizio; Castellini, Elena; Malferrari, Daniele ( 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 - RENDICONTI LINCEI. SCIENZE FISICHE E NATURALI - n. volume 28 - pp. da 605 a 614 ISSN: 2037-4631 [Articolo in rivista (262) - Articolo su rivista]
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.

Ferretti, Annalisa; Malferrari, Daniele; Medici, Luca; Savioli, Martina ( 2017 ) - Diagenesis does not invent anything new: Precise replication of conodont structures by secondary apatite - SCIENTIFIC REPORTS - n. volume 7 - pp. da 1624 a 1632 ISSN: 2045-2322 [Articolo in rivista (262) - Articolo su rivista]
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.

Bernini, Fabrizio; Castellini, Elena; Malferrari, Daniele; Castro, German Rafael; Sainz Díaz, Claro Ignacio; Brigatti, Maria Franca; Borsari, Marco ( 2017 ) - Effective and Selective Trapping of Volatile Organic Sulfur Derivatives by Montmorillonite Intercalated with a μ-oxo Fe(III)-Phenanthroline Complex - ACS APPLIED MATERIALS & INTERFACES - n. volume 9 - pp. da 1045 a 1056 ISSN: 1944-8244 [Articolo in rivista (262) - Articolo su rivista]
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.

Malferrari, Daniele; Bernini, Fabrizio; Tavanti, Francesco; Tuccio, Luca; Pedone, Alfonso ( 2017 ) - Experimental and Molecular Dynamics Investigation Proves That Montmorillonite Traps the Biogenic Amines Histamine and Tyramine - JOURNAL OF PHYSICAL CHEMISTRY. C - n. volume 121 - pp. da 27493 a 27503 ISSN: 1932-7447 [Articolo in rivista (262) - Articolo su rivista]
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.

Eslami, Mahboubeh; Khorassani, Reza; Coltorti, Massimo; Malferrari, Daniele; Faccini, Barbara; Ferretti, Giacomo; Di Giuseppe, Dario; Fotovat, Amir; Halajnia, Akram ( 2017 ) - Leaching behaviour of a sandy soil amended with natural and NH4+and K+saturated clinoptilolite and chabazite - ARCHIV FÜR ACKER- UND PFLANZENBAU UND BODENKUNDE. - pp. da 1 a 10 ISSN: 0365-0340 [Articolo in rivista (262) - Articolo su rivista]
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.

Medici, Luca; Ferretti, Annalisa; Malferrari, Daniele; Cavalazzi, Barbara; Savioli, Martina ( 2017 ) - Mineralogical charcaterization of apatite biominerals: preliminary results ( - Fourth International Conodont Symposium. ICOS IV "Progress on Conodont Investigation". ) - n. volume 22 - pp. da 301 a 302 ISSN: 1699-8693 [Contributo in volume (Capitolo o Saggio) (268) - Capitolo/Saggio]
Abstract

Bioapatite fossils are investigated and compared by the use of microdiffraction technique.

Campisi, T.; Abbondanzi, F.; Faccini, B.; Di Giuseppe, D.; Malferrari, D.; Coltorti, M.; Laurora, A.; Passaglia, E. ( 2016 ) - Ammonium-charged zeolitite effects on crop growth and nutrient leaching: Greenhouse experiments on maize (Zea mays) - CATENA - n. volume 140 - pp. da 66 a 76 ISSN: 0341-8162 [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti, Maria Franca; Elmi, Chiara; Guggenheim, Stephen; Malferrari, Daniele; Poppi, Marco; ( 2016 ) - An alternative method of calculating cleavage energy: The effect of compositional domains in micas - AMERICAN MINERALOGIST - n. volume 101 - pp. da 2738 a 2746 ISSN: 0003-004X [Articolo in rivista (262) - Articolo su rivista]
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.

Ferretti, Annalisa; Malferrari, Daniele; Medici, Luca; Savioli, Martina ( 2016 ) - Crystals on the rocks. Apatite overgrowth on conodont elements from the Late Ordovician of Normandy, France ( IGCP 591: The Early to Middle Paleozoic Revolution. Closing Meeting - Ghent University, Belgium - 6-9 July 2016) ( - IGCP 591: The Early to Middle Paleozoic Revolution ) - pp. da 103 a 103 ISSN: - [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
Abstract

Apatite overgrowth patterns on Ordovician conodonts are here referred to metamorphism.

Ventruti, Gennaro; Ventura, Giancarlo Della; Corriero, Nicola; Malferrari, Daniele; Gualtieri, Alessandro F.; Susta, Umberto; Lacalamita, Maria; Schingaro, Emanuela ( 2016 ) - In situ high-temperature X-ray diffraction and spectroscopic study of fibroferrite, FeOH(SO4)·5H2O - PHYSICS AND CHEMISTRY OF MINERALS - n. volume 43(8) - pp. da 587 a 595 ISSN: 0342-1791 [Articolo in rivista (262) - Articolo su rivista]
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.

Ferretti, Annalisa; Malferrari, Daniele; Medici, Luca; Savioli, Martina ( 2016 ) - Overgrowth of apatite crystals on the surface of Late Ordovician conodonts from Normandy, northern France ( La Società Paleontologica Italiana a Faenza: XVI Riunione annuale SPI, Faenza. - Museo Civico di Scienze Naturali “Malmerendi”, Faenza - 25-27 May 2016) ( - PALEODAYS 2016. La Società Paleontologica Italiana a Faenza: XVI Riunione annuale SPI, Faenza. ) - pp. da 46 a 47 ISBN: 9791220009836 ISSN: - [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
Abstract

Peculiar apatite overgrowth on Ordovician conodont elements are described.

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 ( 2016 ) - Pre-amyloid oligomers budding:a metastatic mechanism of proteotoxicity - SCIENTIFIC REPORTS - n. volume 6 - pp. da 35865 a 35875 ISSN: 2045-2322 [Articolo in rivista (262) - Articolo su rivista]
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.

Muniz-Miranda, Francesco; Lodesani, Federica; Tavanti, Francesco; Presti, Davide; Malferrari, Daniele; Pedone, Alfonso ( 2016 ) - Supercritical CO2 Confined in Palygorskite and Sepiolite Minerals: A Classical Molecular Dynamics Investigation - JOURNAL OF PHYSICAL CHEMISTRY. C - n. volume 120 - pp. da 26945 a 26954 ISSN: 1932-7447 [Articolo in rivista (262) - Articolo su rivista]
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).

Nardelli, M. P.; Malferrari, Daniele; Ferretti, Annalisa; Bartolini, A.; Sabbatini, A.; Negri, A. ( 2016 ) - Zinc incorporation in the miliolid foraminifer Pseudotriloculina rotunda under laboratory conditions - MARINE MICROPALEONTOLOGY - n. volume 126 - pp. da 42 a 49 ISSN: 0377-8398 [Articolo in rivista (262) - Articolo su rivista]
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.

Faccini, Barbara; Di Giuseppe, Dario; Malferrari, Daniele; Coltorti, Massimo; Abbondanzi, Federica; Campisi, Tiziana; Laurora, Angela; Passaglia, Elio ( 2015 ) - Ammonium-exchanged zeolitite preparation for agricultural uses: From laboratory tests to large-scale application in ZeoLIFE project prototype - PERIODICO DI MINERALOGIA - n. volume 84 - pp. da 303 a 321 ISSN: 0369-8963 [Articolo in rivista (262) - Articolo su rivista]
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

Ferretti, Annalisa; Cavalazzi, Barbara; McLaughlin, Patrick I.; Barbieri, Roberto; Emsbo, Poul; Foucher, Frédéric; Malferrari, Daniele; Messori, Fabio; Westall, Frances ( 2015 ) - Can facies act as a chronostratigraphical tool? ( 2nd International Congress of Stratigraphy STRATI 2015 - Graz, Austria - 19- 23 July 2015) ( - Abstracts ) - BERICHTE DES INSTITUTES FÜR GEOLOGIE UND PALÄONTOLOGIE DER KARL-FRANZENS-UNIVERSITÄT GRAZ, ÖSTERREICH - n. volume 21 - pp. da 108 a 108 ISSN: 1608-8166 [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
Abstract

Results demonstrate that the Appalachian ironstones seem to reflect the same microbially-mediated iron mineralization already documented in the Carnic Alps.

Malferrari, Daniele; Laurora, Angela ( 2015 ) - I minerali e i metodi sperimentali per la determinazione delle nuove specie mineralogiche ( - Minerali della provincia di Reggio Emilia ) (AMI - Ass. Micromineralogica Italiana ITA ) - pp. da 11 a 33 ISBN: 9788890554124 ISSN: - [Contributo in volume (Capitolo o Saggio) (268) - Capitolo/Saggio]
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.

Bernini, Fabrizio; Castellini, Elena; Malferrari, Daniele; Borsari, Marco; Brigatti, Maria Franca ( 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 - MICROPOROUS AND MESOPOROUS MATERIALS - n. volume 211 - pp. da 19 a 29 ISSN: 1387-1811 [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti, Maria Franca; Affronte, Marco; Elmi, Chiara; Malferrari, Daniele; Laurora, Angela ( 2015 ) - Trioctahedral Fe-rich micas: Relationships between magnetic behavior and crystal chemistry - AMERICAN MINERALOGIST - n. volume 100 - pp. da 2231 a 2241 ISSN: 0003-004X [Articolo in rivista (262) - Articolo su rivista]
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.

Faccini, Barbara; Di Giuseppe, Dario; Colombani, Nicolò; Mastrocicco, Micol; Malferrari, Daniele; Coltorti, Massimo; Ferretti, Giacomo; ( 2014 ) - COLUMN LEACHING EXPERIMENTS ON AMMONIUM CHARGED ZEOLITITE - EQA - n. volume 14 - pp. da 43 a 52 ISSN: 2281-4485 [Articolo in rivista (262) - Articolo su rivista]
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.

Galli, Ermanno; Brigatti, MariaFranca; Malferrari, Daniele; Sauro, Francesco; De Waele, Jo ( 2013 ) - IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) - MINERALOGICAL MAGAZINE - n. volume 77 - pp. da 1 a 12 ISSN: 0026-461X [Articolo in rivista (262) - Articolo su rivista]
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

Angela, Laurora; Daniele, Malferrari; Passaglia, Elio ( 2013 ) - Impianto per trattare sostanze organiche e produrre un materiale fertilizzante [Brevetto (285) - Brevetto]
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.

D. Malferrari;A. Laurora;M. Brigatti;M. Coltorti;D. D. Giuseppe;B. Faccini;E. Passaglia;M. Vezzalini ( 2013 ) - Open-field experimentation of an innovative and integrated zeolitite cycle: Project definition and material characterization - RENDICONTI LINCEI. SCIENZE FISICHE E NATURALI - n. volume 24 - pp. da 141 a 150 ISSN: 2037-4631 [Articolo in rivista (262) - Articolo su rivista]
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.

Galli E.; Brigatti M.F.; Malferrari D.; Sauro F.; De Waele J. ( 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 - AMERICAN MINERALOGIST - n. volume 98 - pp. da 1906 a 1913 ISSN: 0003-004X [Articolo in rivista (262) - Articolo su rivista]
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.

Elmi C; Brigatti M.F.; Guggenheim;S.; Pasquali L.; Montecchi M.; Malferrari D.; Nannarone S. ( 2013 ) - Sodian muscovite-2M1: crystal chemistry and surface features - CANADIAN MINERALOGIST - n. volume 51 - pp. da 5 a 14 ISSN: 0008-4476 [Articolo in rivista (262) - Articolo su rivista]
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.

Castellini E.; Berthold C.; Malferrari D.; Bernini F ( 2013 ) - Sodium hexametaphosphate interaction with 2:1 clay minerals illite and montmorillonite - APPLIED CLAY SCIENCE - n. volume 83-84 - pp. da 162 a 170 ISSN: 0169-1317 [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti, .M.F.; Laurora, A.; Malferrari, D.; Passaglia, E.; Vezzalini, G. ( 2013 ) - Use of zeolitites from Central Italy in an integrated cycle aimed at water and chemical fertilizers saving (ZEOLIFE – LIFE+10ENV/IT/000321) ( 17th International Zeolite Conference - Moscow - July, 7-12, 2013) ( - Atti del 17th International Zeolite Conference ) (- Moscow RUS ) - n. volume 1 - pp. da 243 a 244 ISBN: - ISSN: - [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
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).

D. Malferrari; A. Laurora; C. Elmi; M. F. Brigatti; L. Medici; M. C. Zeqireja ( 2012 ) - Channel Sediment Characterization and Evaluation of the Potential Impact of Iron-Rich Phases on the Use of Sediments in Brick Production - ENVIRONMENTAL ENGINEERING SCIENCE - n. volume 29(9) - pp. da 840 a 847 ISSN: 1092-8758 [Articolo in rivista (262) - Articolo su rivista]
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.

S. Pini; M. F. Brigatti; M. Affronte; D. Malferrari; A. Marcelli ( 2012 ) - Magnetic behavior of trioctahedral micas with different octahedral Fe ordering - PHYSICS AND CHEMISTRY OF MINERALS - n. volume 39(8) - pp. da 665 a 674 ISSN: 0342-1791 [Articolo in rivista (262) - Articolo su rivista]
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.

Coltorti, M.; Giuseppe, D. D.; Faccini, B.; Passaglia, E.; Malferrari, Daniele; Mastrocicco, M.; Colombani, N. ( 2012 ) - ZeoLIFE, a project for water pollution reduction and water saving using a natural zeolitite cycle ( - - - - 2012) ( - Rendiconti Online della SGI ) - RENDICONTI ONLINE DELLA SOCIETÀ GEOLOGICA ITALIANA - n. volume 21 - pp. da 853 a 853 ISSN: 2035-8008 [Abstract in rivista (266) - Abstract in Rivista]
Abstract

ZeoLIFE, a project for water pollution reduction and water saving using a natural zeolitite cycle

A. Bellini; D. Malferrari; V. Iannuccelli; G. Coppi ( 2011 ) - Characterization of gentamicin-bentonite complex ( Pharmaceutical Sciences for the Future of Medicine - Praga - Repubblica Ceca - 13-17 june 2011) ( - Pharmaceutical Sciences for the Future of Medicine ) (ND ND CZE ) - n. volume ND - pp. da 117 a 117 ISBN: 9780000000002 ISSN: - [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
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.

C. Elmi; M.F. Brigatti; L. Pasquali; M. Montecchi; S. Nannarone; D. Malferrari ( 2011 ) - Crystal chemistry and surface features of a 2M1 paragonitic muscovite ( Geoitalia 2011 - Torino - 19-23 settembre 2001) ( - Epitome ) - EPITOME - n. volume 4 - pp. da 218 a 219 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
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.

A. Laurora; M.F. Brigatti; D. Malferrari; E. Galli; A. Rossi; M. Ferrari ( 2011 ) - Crystal chemistry of lizardite-1T from Northen Apennines Ophiolites (Italy) ( Geoitalia 2011 - Torino - 19-23 settembre 2011) ( - Epitome ) (FIST Udine ITA ) - EPITOME - n. volume 4 - pp. da 220 a 220 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
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.

Daniele Malferrari; Maria Franca Brigatti; Chiara Elmi; Angela Laurora ( 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) - NEUES JAHRBUCH FUR MINERALOGIE-ABHANDLUNGEN - n. volume 188/1 - pp. da 65 a 74 ISSN: 0077-7757 [Articolo in rivista (262) - Articolo su rivista]
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.

C. Elmi; M. F. Brigatti; L. Pasquali;M. Montecchi; A. Laurora; D. Malferrari;S. Nannarone ( 2011 ) - High-temperature vesuvianite: crystal chemistry and surfaceconsiderations - PHYSICS AND CHEMISTRY OF MINERALS - n. volume 38 - pp. da 459 a 468 ISSN: 0342-1791 [Articolo in rivista (262) - Articolo su rivista]
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.

C. Elmi; M.F. Brigatti; D. Malferrari ( 2011 ) - Layer charge location in layer silicates and its implications ( Geoitalia 2011 - Torino - 19-23 settembre 2011) ( - Epitome ) - EPITOME - n. volume 4 - pp. da 220 a 220 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
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.

E. Castellini; M. Bert; C. Berthold; M.F. Brigatti; D. Malferrari ( 2011 ) - Sodium hexametaphosfate interactions with illite and montmorillonite: preliminary observation on thermal behavior ( Geoitalia 2011 - Torino - 19-23 settembre 2011) ( - Epitome ) (FIST Udine ITA ) - EPITOME - n. volume 4 - pp. da 221 a 221 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
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.

Brigatti, Maria Franca; Malferrari, Daniele; Laurora, Angela; Elmi, Chiara ( 2011 ) - Structure and mineralogy of layer silicates ( - Layered mineral structures and their application in advanced technologies ) (MINERALOGICAL SOCIETY GREAT BRITAIN & IRELAND GBR ) - n. volume 11 - pp. da 1 a 71 ISBN: 9780903056298; 9780903056458; 9780903056298; 97809 | 9780903056458 | 9780903056298 ISSN: - [Contributo in volume (Capitolo o Saggio) (268) - Capitolo/Saggio]
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.

Brigatti M.F.; Malferrari D.; Laurora A.; Elmi C. ( 2011 ) - Structure and mineralogy of layer silicates: recent perspectives and new trends ( EMU School 2001 - Roma - 9-19 luglio 2011) ( - Book of Abstract ) (Brigatti M.F., Mottana A. Modena e Roma ITA ) - pp. da 5 a 5 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

Layer silicates are experiencing an increasing interest from the scientific and technical community, in relation to their application in many novel and advanced areas. The correct application of these minerals requires a deep understanding of their properties and of the processes where they are involved. This chapter, by providing fundamental denitions and data pertaining to layer silicates, is aimed at introducing into this eld a novel or yet experienced researcher or technician, thus describing the fundamental features leading to dierent layer silicates behaviour in dierent natural or technical processes, as better detailed in other chapters of this book. The matter addressed is extremely vast, thus suggesting to condensate or to omit more consolidated knowledge, already available to the reader via numerous review works and volumes, quoted in this chapter.More details were provided on minerals being characterized by applicative signicance or by a greater amount of information available in literature on their crystal structure and chemistry.

Brigatti, Maria Franca; Malferrari, Daniele; Laurora, Angela; Elmi, Chiara ( 2011 ) - Structure and mineralogy of layer silicates: recent perspectives and new trends ( - Layered mineral structures and their Application in Advanced Technologies ) (The Mineralogical Society of Great Britain and Ireland Twickenham, Middlesex, TW1 3HQ GBR ) - n. volume 11 - pp. da 1 a 71 ISBN: 9780903056274 ISSN: - [Contributo in volume (Capitolo o Saggio) (268) - Capitolo/Saggio]
Abstract

Layer silicates are experiencing an increasing interest from the scientific and technical community, in relation to their application in many novel and advanced areas. The correct application of these minerals requires a 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, is aimed at introducing into this field a novel or not yet experienced researcher or technician, thus describing the fundamental features leading to different layer silicates behaviour in different natural or technical processes, as better detailed in other chapters of this book. The matter addressed is extremely vast, thus requiring to condensate or to omit more consolidated knowledge, already available to the reader by numerous review works and volumes, quoted in this chapter. This chapter will thus be focused on layer silicates for which crystal structure is better detailed in literature and/or enjoying significant or future applicative appeal. Layer silicate minerals, fulfilling these requirements, and thus detailed in the body of this chapter, are minerals of the: i) 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); ii) talc and pyrophyllite group (e.g. pyrophyllite, ferripyrophyllite, willemseite); iii) mica group (i.e. some recent advances on crystal chemistry and structure of dioctahedral and trioctahedral micas); iv) smectite group (e.g. montmorillonite, saponite, hectorite, sauconite, stevensite, swinefordite); v) vermiculite group; vi) chlorite group (e.g. trioctahedral chlorite such as clinochlore, di,trioctahedral, and dioctahedral chlorites such as cookeite and sudoite); vii) some 2:1 layer silicates involving a discontinuous octahedral sheet and a modulated tetrahedral sheet such as kalifersite, palygorskite and sepiolite; viii) imogolite and allophane

D. Malferrari; M.F. Brigatti; A. Laurora; R. Sassi; F.P. Sassi ( 2011 ) - Textural study of metamorphic rocks by means of a conventional X-ray source ( Geoitalia 2011 - Torino - 19-23 settembre 2011) ( - Epitome ) (FIST udine ITA ) - EPITOME - n. volume 4 - pp. da 221 a 221 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
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.

Laurora A.; Brigatti M.F.; Malferrari D.; Galli E.; Rossi A.; Ferrari M. ( 2011 ) - The crystal chemistry of lizardite-1T from Northern Apennines ophiolites near Modena, Italy - CANADIAN MINERALOGIST - n. volume 49 - pp. da 1045 a 1054 ISSN: 0008-4476 [Articolo in rivista (262) - Articolo su rivista]
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.

Elmi C.; Brigatti M. F.; Pasquali L.; Montecchi M.; Laurora A.; Malferrari D.; Nannarone S. ( 2010 ) - Crystal chemistry, surface morphology and X-ray photoelectron spectroscopy of Fe-rich osumilite from Mt. Arci, Sardinia (Italy) - PHYSICS AND CHEMISTRY OF MINERALS - n. volume 37(8) - pp. da 561 a 569 ISSN: 0342-1791 [Articolo in rivista (262) - Articolo su rivista]
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.

Malferrari D.; Brigatti M. F.; Marcelli A.; Chu W.; Wu Z. ( 2010 ) - Effect of temperature on Hg-cysteine complexes in vermiculite and montmorillonite - APPLIED CLAY SCIENCE - n. volume 50(1) - pp. da 12 a 18 ISSN: 0169-1317 [Articolo in rivista (262) - Articolo su rivista]
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.

Malferrari D.; Brigatti M.F.; Marcelli A.; Chu W.; Wu Z. ( 2010 ) - Effect of temperature on Hg-cysteine complexes in vermiculite and montmorillonite ( IMA 2010, 20th General Meeting of the International Mineralogical Association - Budapest (Ungheria) - 21-27 Agosto 2010) ( - Acta Mineralogica-Petrographica Abstract Series ) - n. volume 6 - pp. da 852 a 852 ISSN: 1589-4835 [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
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.

Bortolotti D.; Brigatti M.F.; Elmi C.; Malferrari D.; Pattuzzi E. ( 2010 ) - Relationship between morphological preferred orientations and landslides ( IMA 2010, 20th General Meeting of the International Mineralogical Association - Budapest (Ungheria) - 21-27 Agosto 2010) ( - Mineralogica-Petrographica Abstract Series ) - n. volume 6 - pp. da 856 a 856 ISSN: 1589-4835 [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
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.

Elmi C.; Brigatti M.F.; Malferrari D.; Castro G.R.; Ferrer Escorihuela P. ( 2010 ) - Surface structure of natural muscovite ( IMA 2010, 20th General Meeting of the International Mineralogical Association - Budapest (Ungheria) - 21-27 Agosto 2010) ( - Acta Mineralogica-Petrographica Abstract Series ) - n. volume 6 - pp. da 753 a 753 ISSN: 1589-4835 [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
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.

Elmi C.; Brigatti M.F; Pasquali L.; Montecchi M.; Nannarone S.; Laurora A.; Malferrari D. ( 2010 ) - The relationships of bulk structure, surface structure, chemistry, and physical properties of mineral phases with six- and eight-membered silicate rings ( IMA 2010, 20th General Meeting of the International Mineralogical Association - Budapest (Ungheria) - 21-27 Agosto 2010) ( - Acta Mineralogica-Petrographica Abstract Series ) - n. volume 6 - pp. da 710 a 710 ISSN: 1589-4835 [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
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.

Affronte M.; Brigatti M.F.; Malferrari D.; Marcelli A.; Pini S. ( 2010 ) - Trioctahedral micas: relationships between crystal chemistry and magnetic behavior ( IMA 2010, 20th General Meeting of the International Mineralogical Association - Budapest (Ungheria) - 21-27 Agosto 2010) ( - Acta Mineralogica-Petrographica Abstract Series ) - n. volume 6 - pp. da 852 a 852 ISSN: 1589-4835 [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
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 phlogopite – 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.

Marchetto P.; Brigatti M.F.; Laurora A.; Malferrari D. ( 2010 ) - Use of perlite in combination with clays for the production of low environmental impact filter for heavy metals polluted aqueous solution ( IMA 2010, 20th General Meeting of the International Mineralogical Association - Budapest (Ungheria) - 21-27 Agosto 2010) ( - Acta Mineralogica-Petrographica Abstract Series ) - ACTA MINERALOGICA-PETROGRAPHICA. ABSTRACT SERIES - n. volume 6 - pp. da 14 a 14 ISSN: 1589-4835 [Abstract in rivista (266) - Abstract in Rivista]
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.

D. MALFERRARI; M.F. BRIGATTI; M.G. VEZZALINI; A. LAURORA ( 2010 ) - Water pollution reduction and water saving using a natural zeolitite cycle [Altro (298) - Partecipazione a progetti di ricerca]
Abstract

GENERAL OBJECTIVES OF THE PROJECT 1)The protection of fresh and groundwater from nitrate pollution derived by agronomic industry. 2)The reduction of water and soil pollution derived by punctual (cattle breeding) and diffuse (agriculture) sources of nitrates. 3)The qualitative and quantitative preservation of the water resource. 4)The reduction and the prevention of pollution of seawater. 5)The optimization of the use of water in agriculture and a minor use of chemical fertilizers. 6)An improvement of agricultural soil characteristics. 7)The experimentation of a possible way to contrast desertification and agricultural soil exhaustion.

Malferrari D.; Pistoni R.; Laurora A.; Brigatti M.F.; Mantovani E.; Tonelli F. ( 2009 ) - Approvvigionamento idrico e manutenzione delle infrastrutture idrauliche di bonifica: il problema dello smaltimento dei sedimenti dei canali ( La crisi dei sistemi idrici: approvvigionamento agro-industriale e civile. - ROMA - 22/03/2007) ( - La crisi dei sistemi idrici: approvvigionamento agro-industriale e civile ) (Accademia Nazionale dei Lincei ROMA ITA ) - n. volume 248 - pp. da 143 a 152 ISBN: 9788821810077 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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).

M.F. Brigatti; C. Elmi; A. Laurora; D. Malferrari; L. Medici ( 2009 ) - Combined mineralogical and EXAFS characterization of polluted sediments for the definition of technological variables and constraints ( EGU2009 - Vienna, Austria - 19-24 Aprile 2009) ( - Geophysical Research Abstracts ) - GEOPHYSICAL RESEARCH ABSTRACTS - n. volume 11 [Abstract in rivista (266) - Abstract in Rivista]
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.

Laurora A.; Malferrari D.; Brigatti M.F.; Mottana A.; Caprilli E.; Giordano G.; Funiciello R. ( 2009 ) - Crystal chemistry of trioctahedral micas in the top sequences of the Colli Albani volcano, Roman Region, Central Italy ( Geoitalia 2009 7° Forum Italiano di Scienze della Terra - Rimini (Italia) - 09-11 Settembre 2009) ( - Epitome ) (FIST Udine ITA ) - EPITOME - n. volume 3 - pp. da 17 a 17 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
Abstract

Trioctahedralmicacrystals are frequently found in the volcanoclastic products emplaced during the final stages of the activity of the ColliAlbanivolcano (RomanRegion, centralItaly). In the youngest phreatomagmatic deposits, mica is found either as a minor mineral phase in holocrystalline ejecta, scoriae, and coherent pyroclastics, or as loose phenocryst 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

A. Laurora; D. Malferrari; M.F. Brigatti; A. Mottana; E. Caprilli;G. Giordano; R. Funiciello ( 2009 ) - Crystal chemistry of trioctahedral micas in the top sequences of the Colli Albani volcano, Roman Region, central Italy - LITHOS - n. volume 113(3-4) - pp. da 507 a 520 ISSN: 0024-4937 [Articolo in rivista (262) - Articolo su rivista]
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.

G. Valdré; D. Malferrari; M.F. Brigatti ( 2009 ) - CRYSTALLOGRAPHIC FEATURES AND CLEAVAGE NANOMORPHOLOGY OF CHLINOCHLORE: SPECIFIC APPLICATIONS - CLAYS AND CLAY MINERALS - n. volume 57-2 - pp. da 183 a 193 ISSN: 0009-8604 [Articolo in rivista (262) - Articolo su rivista]
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.

Malferrari D ; Brigatti MF ; Laurora A ; Pini S ( 2009 ) - Heavy metals in sediments from canals for water supplying and drainage: mobilization and control strategies - JOURNAL OF HAZARDOUS MATERIALS - n. volume 161 - pp. da 723 a 729 ISSN: 0304-3894 [Articolo in rivista (262) - Articolo su rivista]
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.

A. Laurora; D. Malferrari; P. Fregni ( 2009 ) - LA DIDATTICA DELLE SCIENZE DELLA TERRA - UNIVERSITÀ E SCUOLA - n. volume XIV-1 - pp. da 43 a 54 ISSN: 1124-5492 [Articolo in rivista (262) - Articolo su rivista]
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.

D. Malferrari; M.F. Brigatti; C. Elmi; A. Laurora; G. Valdre ( 2009 ) - Layer charge and heavy metals structures in hydrated 2 : 1 silicates:state of the art and new advances on cadmium - ZEITSCHRIFT FUR KRISTALLOGRAPHIE - n. volume 224 - pp. da 311 a 315 ISSN: 0044-2968 [Articolo in rivista (262) - Articolo su rivista]
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 (CdO distances of 2.24 Å) and six-fold coordination in vermiculite (CdO 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.

Malferrari D.; Brigatti M.F.; Laurora A.; Venturini S. ( 2009 ) - Mobilization of heavy metals from fluvial sediments (Tiepido river, Modena, Italy): mineralogical and chemical investigation to prevent potential environmental hazard ( Geoitalia 2009 7° Forum Italiano di Scienze della Terra - Rimini (Italia) - 09-11 Settembre 2009) ( - Epitome ) (FIST Udine ITA ) - EPITOME - n. volume 3 - pp. da 100 a 100 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
Abstract

nd

Malferrari D.; Brigatti M.F.; Laurora A.; Zanerini L. ( 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 ( Geoitalia 2009 7° Forum Italiano di Scienze della Terra - Rimini (Italia) - 09-11 Settembre 2009) ( - Epitome ) (FIST Udine ITA ) - EPITOME - n. volume 3 - pp. da 25 a 25 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
Abstract

nd

Pini S.; Affronte M.; Brigatti M.F.; Malferrari D.; Marcelli A. ( 2009 ) - Octahedral cation ordering and magnetic behavior of micas ( Geoitalia 2009 7° Forum Italiano di Scienze della Terra - Rimini (Italia) - 09-11 Settembre 2009) ( - Epitome ) (FIST Udine ITA ) - EPITOME - n. volume 3 - pp. da 13 a 13 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
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.

Elmi C.; Brigatti M.F; Pasquali L.; Montecchi M.; Laurora A.; Malferrari D.; Nannarone S. ( 2009 ) - Osumilite from Mount Arci (Sardinia, Italy): bulk and surface crystal chemistry ( Geoitalia 2009 7° Forum Italiano di Scienze della Terra - Rimini (Italia) - 09-11 Settembre 2009) ( - Plinius ) - PLINIUS - n. volume 35 - pp. da 744 a 745 ISSN: 1972-1366 [Abstract in rivista (266) - Abstract in Rivista]
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.

Elmi C.; Brigatti M.F; Malferrari D.; Castro G.R.; Ferrer-Escorihuela P.; Rubio-Zuazo J. ( 2009 ) - Relationship between bulk and surface structure of muscovite ( Geoitalia 2009 7° Forum Italiano di Scienze della Terra - Rimini (Italia) - 09-11 Settembre 2009) ( - Epitome ) - EPITOME - n. volume 3 - pp. da 15 a 15 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
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.

M.F. Brigatti; S. Guggenheim; E. Passaglia; D. Malferrari; C. Elmi ( 2009 ) - The relationship of bulk structure, surface structure, chemistry, and physical properties of mineral phases with six-membered silicate rings [Altro (298) - Partecipazione a progetti di ricerca]
Abstract

The goal of the proposed 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, primarily phyllosilicates (e.g., serpentines, micas, chlorites) and zeolites (e.g., chabazite, levyne). These minerals are common: they are found in many environments and they readily interact with these environments by adsorption and exchange reactions, in addition to transformations to other phases. Adsorption and exchange processes can modify the concentration of heavy metals, gases, biological and microbial agents, pharmaceutical products, fertilizers, etc. Resulting changes in the concentration of these products are often assessed by measuring the change in the concentration of the products over time. However, because adsorption and exchange reactions occur both on external surfaces and on accessible internal (bulk) surfaces, a more fundamental approach is to examine the effect of atomic arrangement (e.g., both the bulk crystal structure and the surface arrangement) and chemical composition on these processes (in addition to measuring changes in product concentration). The overall project objectives are to define: i) protocols for the selection of the best suited six-membered silicates for supporting a given exchange mechanism; ii) the development of exchange mechanism(s) at an atomic level and how they are modified by environmental (or thermodynamic) changes associated with the environment or micro-environment.

Elmi C.; Brigatti M.F; Malferrari D.; Valdrè G.; Castro G.R.; Rubio-Zuazo J. ( 2008 ) - Clinochlore structure and its surface interactions with organic molecoles ( 1st SIMP-AIC Joint Meeting - Sestri Levante, Genova (Italia) - 07-12 Settembre 2008) ( - Book of Abstract ) (Società Italiana di Mineralogia e Petrologia Pisa ITA ) - pp. da 197 a 197 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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.

Brigatti M.F.; Malferrari D.; Mottana A.; Cibin G.; Marcelli A.; Cinque G. ( 2008 ) - Crystal chemical modeling and XANES spectroscopy of potassium micas ( II International Workshop of Layered Materials - Vercelli (Italia) - 28-30 Marzo 2008) ( - Book of Abstract ) (Università del Piemonte Orientale e Università di Torino Torino ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

nd

Valdrè G.; Brigatti M.F.; Malferrari D. ( 2008 ) - DNA interactions with clinochlore surface ( II International Workshop of Layered Materials - Vercelli (Italia) - 28-30 Marzo 2008) ( - Book of Abstract ) (Università del Piemonte Oritentale e Università di Torino Torino ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

nd

Malferrari D.; Brigatti M.F.; Elmi C.; Marcelli A.; Chu W.; Wu Z. ( 2008 ) - Effect of temperature on Hg- and Hg-cysteine complexes in vermiculite and montmorillonite interlayer ( 1st SIMP-AIC Joint Meeting - Sestri Levante, Genova (Italia) - 07-12 Settembre 2008) ( - Book of Abstract ) (Società Italiana di Mineralogia e Petrologia Pisa ITA ) - pp. da 187 a 187 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

Presentazione orale

M.F. Brigatti; D. Malferrari; A. Laurora; C. Elmi; E. Petrini ( 2008 ) - Fillosilicati di particolare interesse petrologico: caratteri chimici e fisici, e loro variazione in contesti naturali e simulati [Altro (298) - Partecipazione a progetti di ricerca]
Abstract

Nel corso dello svolgimento del PRIN 2006 il gruppo proponente ha raggiunto risultati di rilievo a livello nazionale ed internazionale nel campo della caratterizzazione cristallochimica e cristallofisica di miche di- e triottaedriche. Lo studio di questi minerali ha conferito al gruppo, che annovera competenze incristallografia, petrologia, petrografia, microscopia elettronica e tecniche spettroscopiche, il valore aggiunto di un approccio multi-metodico e multi-competenze e l'impostazione petrologica rigorosa nella scelta dei campioni.L'attuale progetto di ricerca estenderà il campo di indagine anche ad altri fillosilicati (in particolare cloriti), al fine di approfondire le conoscenze sulle loro caratteristiche mineralogiche, cristallochimiche e cristallofisiche in contesti petrologici rigorosamente definiti. Il progetto è pertanto finalizzato a dimostrare, fornendo indicazioni quantitative e predittive, che: i) caratteristiche cristallografiche, cristallochimiche e cristallofisiche di miche e cloriti sono influenzate dalle condizioni petrologiche in cui esse si sono generate e/o riequilibrate; ii) modelli teorici e statistici, opportunamente formulati e calibrati, contribuiscono a definire le relazioni tra proprietà del minerale, condizioni termodinamiche e cinetica di cristallizzazione; iii) struttura, proprietà topologiche e ordinamento cationico influenzano la reattività dei fillosilicati nei processi di cristallizzazione e riequilibrio. Inoltre, la realizzazione di questi obiettivi non può prescindere dal rigoroso studio dei contesti petrologici esaminati.

P. Marchetto; A. Laurora; D. Malferrari; M.F. Brigatti; G. Bosi ( 2008 ) - I suoli a mirtillo (Appennino Modenese) ( Il mirtillo nero del Frignano - Pavullo (MO) - 25 Maggio 2007) - ATTI DELLA SOCIETÀ DEI NATURALISTI E MATEMATICI DI MODENA - n. volume 138 (suppl.) (2007) - pp. da 63 a 93 ISSN: 0365-7027 [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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.

M. BRIGATTI; MALFERRARI D; POPPI M; MOTTANA A; CIBIN G; MARCELLI A; CINQUE G ( 2008 ) - Interlayer potassium and its neighboring atoms in micas: Crystal chemical modeling and XANES spectroscopy - AMERICAN MINERALOGIST - n. volume 93 - pp. da 821 a 830 ISSN: 0003-004X [Articolo in rivista (262) - Articolo su rivista]
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.

Valdrè G.; Moro D.; Malferrari D.; Brigatti M.F. ( 2008 ) - Kelvin probe and surface shear microscopy of layer silicates ( II International Workshop of Layered Materials - Vercelli (Italia) - 28-30 Marzo 2008) ( - Book of Abstract ) (Università del Piemonte Orientale e Università di Torino Torino ITA ) - pp. da 4 a 4 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

nd

Malferrari D; Brigatti MF; Marcelli A; Chu W; Wu Z ( 2008 ) - Modification of Hg complexes in layered silicates with temperature: an in situ XAS study - MICROPOROUS AND MESOPOROUS MATERIALS - n. volume 107 - pp. da 128 a 133 ISSN: 1387-1811 [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti MF; Guidotti CV; Malferrari D; Sassi FP ( 2008 ) - Single-crystal X-ray studies of trioctahedral micas coexisting with dioctahedral micas in metamorphic sequences from Western Maine - AMERICAN MINERALOGIST - n. volume 93 - pp. da 735 a 745 ISSN: 0003-004X [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti M.F.; Caprilli E.; Malferrari D.; Mottana A. ( 2008 ) - The octahedral anionic site in micas: a comparison between fluorannite and annite ( II International Workshop of Layered Materials - Vercelli (Italia) - 28-30 Marzo 2008) ( - Book of Abstract ) (Università del Piemonte Orientale e Università di Torino Torino ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

nd

Medici L.; Brigatti M.F.; Malferrari D. ( 2008 ) - X-ray microdiffraction as a tool for single crystal structure refinement: a study on apatite crystals ( 1st SIMP-AIC Joint Meeting - Sestri Levante, Genova (Italia) - 07-12 Settembre 2008) ( - Book of Abstract ) (SIMP Pisa ITA ) - pp. da 102 a 102 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

Poster

Malferrari D.; Brigatti M.F.; Poppi M.; Mottana A.; Cibin G.; Marcelli A.; Cinque G. ( 2007 ) - Crystal chemical modeling and XANES spectroscopy of K in interlayer site of micas ( Geoitalia 2007 - Rimini - 12-14 settembre) ( - Epitome ) (FIST Udine ITA ) - EPITOME - n. volume 2 - pp. da 434 a 434 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
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.

Brigatti M.F.; Malferrari D.; Poppi M.; Mottana A.; Cibin G.; Marcelli A.; Cinque G. ( 2007 ) - Crystal chemical modeling and XANES spectroscopy of the potassium interlayer in micas ( 6th European Conference on Mineral Spectroscopy (ECMS 6) - Stockholm, Sweden - September 8-11, 2007) ( - Book of Abstract ) (- - ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

nd

Laurora A.; Brigatti MF.; Mottana A.; Malferrari D.; Caprilli E. ( 2007 ) - Crystal chemistry of trioctahedral micas in alkaline and subalkaline volcanic rocks: A case study from Mt. Sassetto (Tolfa district, Latium, central Italy) - AMERICAN MINERALOGIST - n. volume 92 - pp. da 468 a 480 ISSN: 0003-004X [Articolo in rivista (262) - Articolo su rivista]
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).

M. BRIGATTI; MOTTANA A; MALFERRARI D; CIBIN G ( 2007 ) - Crystal structure and chemical composition of Li-, Fe-, and Mn-rich micas - AMERICAN MINERALOGIST - n. volume 92 - pp. da 1395 a 1400 ISSN: 0003-004X [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti MF; Caprilli E; Malferrari D; Mottana A ( 2007 ) - Crystal structure and crystal chemistry of fluorannite and its relationships to annite - MINERALOGICAL MAGAZINE - n. volume 71-6 - pp. da 683 a 690 ISSN: 0026-461X [Articolo in rivista (262) - Articolo su rivista]
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.

M.F. Brigatti; D. Malferrari ( 2007 ) - Il mirtillo nero del Frignano: risorsa da conoscere, valorizzare e difendere [Altro (298) - Altro]
Abstract

Convegno tenutosi a Pavullo nel Frignano (Modena, Italy) il 25 maggio 2007.

Brigatti M.F.; Malferrari D.; Poppi M.; Mottana A.; Cibin G.; Marcelli A.; Cinque G. ( 2007 ) - Interlayer potassium and its surrounding in micas: Crystal chemical modeling and XANES spectroscopy ( European Geosciences Union 2007 - Vienna - 15 - 20 April) ( - Geophysical Research Abstracts ) - GEOPHYSICAL RESEARCH ABSTRACTS - n. volume 9 - pp. da 02410 a 02410 ISSN: 1607-7962 [Abstract in rivista (266) - Abstract in Rivista]
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.

Malferrari D.; Brigatti M.F.; Laurora A.; Pini S.; Pistoni R. ( 2007 ) - Polluted sediments from canals for water supplying and drainege: treatment and recycle ( Geoitalia 2007 - Rimini - 12-14 settembre) ( - Epitome ) (FIST Udine ITA ) - EPITOME - n. volume 2 - pp. da 434 a 434 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
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.

Malferrari D.; Brigatti M.F.; Laurora A.; Pini S.; Pistoni R. ( 2007 ) - Pollution of recent sediments from canals for water supplying and drainage ( Euroclay 2007 - Aveiro, Portugal - 22-27 luglio 2007) ( - Book of Abstract ) (AIPEA - ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

nd

Pistoni R.; Malferrari D.; Brigatti M.F.; Pini S.; Tonelli F. ( 2007 ) - Recupero e valorizzazione di sedimenti estratti da canali di bonifica ed approvvigionamento idrico mediante inertizzazione termica. ( La crisi dei sistemi idrici: Approvvigionamento agro-industriale e civile. - Accademia Nazionale dei Lincei, Roma - 22 marzo 2007) ( - La crisi dei sistemi idrici: Approvvigionamento agro-industriale e civile. ) (Accademia Nazionale dei Lincei Roma ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

nd

Malferrari D.; Borghi V.; Brigatti M.F.; Laurora A.; Mantovani E.; Pistoni R. ( 2007 ) - Sedimenti provenienti dai canali di bonifica: valutazione del potenziale impatto ambientale. ( La crisi dei sistemi idrici: Approvvigionamento agro-industriale e civile - Accademia Nazionale dei Lincei, Roma - 22 marzo 2007) ( - La crisi dei sistemi idrici: Approvvigionamento agro-industriale e civile ) (Accademia Nazionale dei Lincei Roma ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

nd

MALFERRARI D; M. BRIGATTI; LAURORA A; PINI S; MEDICI L ( 2007 ) - Sorption kinetics and chemical forms of Cd(II) sorbed by thiol-functionalized 2:1 clay minerals - JOURNAL OF HAZARDOUS MATERIALS - n. volume 143 - pp. da 73 a 81 ISSN: 0304-3894 [Articolo in rivista (262) - Articolo su rivista]
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.

Valdre G; Malferrari D; Marchetti D; Brigatti MF ( 2007 ) - The effect of different plasma gas environments on vermiculite layer - APPLIED CLAY SCIENCE - n. volume 35 - pp. da 76 a 84 ISSN: 0169-1317 [Articolo in rivista (262) - Articolo su rivista]
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.

M. BRIGATTI; GALLI E; MALFERRARI D; ROSSI A ( 2007 ) - Valutazione dello stato ambientale delle ex aree minerarie a solfuri di Boccassuolo (Palagano, Modena) e Cà Marsilio e Cà Gabriele (Montecreto, Modena) - SOTTO TERRA - n. volume 125 - pp. da 1 a 16 ISSN: - [Articolo in rivista (262) - Articolo su rivista]
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)

Brigatti M. F.; Guidotti C.V.; Malferrari D.; Sassi F.P. ( 2006 ) - Crystal chemistry of some trioctahedral and dioctahedral micas coexisting in metamorphic sequences from N.W. Maine ( GSA Annual Meeting and Exposition, - Philadelphia, Pennsylvania, USA - 22-25 Ottobre 2006) ( - Book of Abstract ) (GSA - USA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Malferrari D.; Brigatti M.F.; Z.Y Wu; W.H. Liu; G. Cibin; A. Marcelli ( 2006 ) - High temperature XAS study D. of Hg and Hg-cysteine complexes in montmorillonite and vermiculite ( XI Congresso EMPG - Bristol (Regno Unito) - 11-13 Settembre 2006) ( - Book of Abstract ) (EMPG - ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Cibin G.; Cinque G.; Malferrari D.; Marcelli A.; Mottana A.; Pini S.; Poppi M. ( 2006 ) - Interlayer material and its surrounding in micas: crystal chemical modeling and XANES spectroscopy ( XXXV Congresso Nazionale A.I.C. - Ferrara (Italia) - 18-21 settembre 2006) ( - Book of Abstract ) (Associazione Italiana di Cristallografia Ferrara ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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M.F. BRIGATTI; E. GALLI; A. ROSSI; A. TOMBESI; G. VALDRE; D. MALFERRARI; A. LAURORA ( 2006 ) - Le miche: ordinamento cationico, popolazione anionica e loro controllo da parte dei fattori petrologici. [Altro (298) - Partecipazione a progetti di ricerca]
Abstract

Marchetto P.; Laurora A.; Malferrari D.; Brigatti M.F.; Bosi G. ( 2006 ) - Soils under bilberry in the Frignano area (Modena Apennine) - ATTI DELLA SOCIETÀ DEI NATURALISTI E MATEMATICI DI MODENA - n. volume 138 - pp. da 63 a 93 ISSN: 0365-7027 [Articolo in rivista (262) - Articolo su rivista]
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Malferrari D.; Brigatti M.F.; Cibin G.; Liu W.H.; Marcelli A.; Wu Z.Y. ( 2006 ) - Structure of Hg complexes in layer silicates: XAS and XRDP high temperature investigation ( XXXV Congresso Nazionale A.I.C. - Ferrara (Italia) - 18-21 settembre 2006) ( - Book of Abstract ) (Associazione Italiana di Cristallografia Ferrara ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Valdrè G.; Malferrari D.; Marchetti D.; M.F. Brigatti ( 2006 ) - The effect of different plasma gas environments on vermiculite layer ( XI Congresso EMPG - Bristol (Regno Unito) - 11-13 Settembre 2006) ( - Book of Abstract ) (EMPG - ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Malferrari D; Brigatti MF; Laurora A; Medici L; Pini S ( 2006 ) - Thermal behavior of Cu(II)-, Cd(II)-, and Hg(II)-exchanged montmorillonite complexedwith cysteine - JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY - n. volume 86-2 - pp. da 365 a 370 ISSN: 1388-6150 [Articolo in rivista (262) - Articolo su rivista]
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.

M.F. Brigatti; A. Laurora; D. Malferrari; L. Medici; L. Poppi ( 2005 ) - Adsorption of [Al(Urea)(6)](3+) and [Cr(Urea)(6)](3+) complexes in the vermiculite interlayer - APPLIED CLAY SCIENCE - n. volume 30 - pp. da 21 a 32 ISSN: 0169-1317 [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti M.F.; Guggenheim S.; Laurora A.; Malferrari D.; Poppi M.; Poppi L. ( 2005 ) - Crystal Chemical Models on Trioctahedral and Dioctahedral Micas ( Micas @ Italy - Rimini (Italia) - 09-11 febbraio 2005) ( - Book of Abstract ) (Gruppo Nazionale PRIN 2004 - ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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MF Brigatti; E. Caprilli; D. Malferrari; L. Medici; L. Poppi ( 2005 ) - Crystal Structure and Chemistry of trilithionite-2M2 and polylithionite-2M2 - EUROPEAN JOURNAL OF MINERALOGY - n. volume 17 - pp. da 475 a 481 ISSN: 0935-1221 [Articolo in rivista (262) - Articolo su rivista]
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.

Marchetti D.; Brigatti M.F.; Laurora A.; Malferrari D.; Valdré G. ( 2005 ) - Interactions of Mica and Vermiculite Layers with Ionized Gasses ( Micas @ Italy - Rimini (Italia) - 09-11 febbraio 2005) ( - Book of Abstract ) (Gruppo Nazionale PRIN 2004 - ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Colonna S.; Malferrari D.; Medici L.; Poppi L. ( 2005 ) - Mercury adsorption by montmorillonite and vermiculite: a combined XRD, TG-MS, and EXAFS study. - APPLIED CLAY SCIENCE - n. volume 28 - pp. da 1 a 8 ISSN: 0169-1317 [Articolo in rivista (262) - Articolo su rivista]
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

Malferrari D.; Brigatti M.F.; Cibin G.; Marcelli A.; Chu W.S.; Wu Z. ( 2005 ) - Modification of Hg-H2O and Hg-cysteine complexes in layered structure with temperature: an X-ray, thermal and XAS study ( XIII Convegno SILS - Modena (Italia) - 5-8 Luglio 2005) ( - Book of Abstract ) (SILS - ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Laurora A.; Malferrari D.; Marchetti D.; Valdré G. ( 2005 ) - Modification of vermiculite surface by ionized gasses ( CMS 2005 – 42nd Annual Meeting - Burlington (U.S.A) - 10-15 giugno 2005) ( - Book of Abstract ) (CMS - USA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Pini S.; Brigatti M.F.; Laurora A.; Malferrari D.; Medici L. ( 2005 ) - Reactions of Cd Ions and Cysteine in Aqueous Solutions with Vermiculite ( Micas @ Italy - Rimini (Italia) - 09-11 febbraio 2005) ( - Book of Abstract ) (Gruppo Nazionale PRIN 2004 - ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Laurora A.; Malferrari D.; Medici L.; Pini S. ( 2005 ) - Sorption kinetics and chemical forms of Cd(II) sorbed by thiol-functionalized 2:1 clays ( CMS 2005 – 42nd Annual Meeting - Burlington (U.S.A) - 10-15 giugno 2005) ( - Book of Abstract ) (CMS - USA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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M.F. Brigatti; A. Laurora; D. Malferrari; S. Pini ( 2005 ) - Study of natural and ion exchanged montmorillonite by thermal analysis (TGA) and evolved gas mass spectrometry (MSEGA) ( Geoitalia 2005 - V Forum Italiano di Scienze della Terra - Spoleto - 21-23 settembre 2005) ( - Epitome 2005, 1 - Geoitalia 2005 ) (FIST Udine ITA ) - EPITOME - n. volume 1 - pp. da 240 a 240 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
Abstract

Presentazione a poster nella sessione "GEO06- Mineralogia- Mineralogy" tenutasi a Spoleto il 23 settembre 2005 in occasione di Geoitalia 2005

Poppi M.; Brigatti M.F.; Malferrari D. ( 2005 ) - The 2M1 Dioctahedral Mica Polytype: A Crystal Chemical Study ( Micas @ Italy - Rimini (Italia) - 09-11 febbraio 2005) ( - Book of Abstract ) (Gruppo Nazionale PRIN 2004 - ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F; Malferrari D.; Poppi M.; Poppi L. ( 2005 ) - The 2M1 dioctahedral mica polytype: a crystal chemical study - CLAYS AND CLAY MINERALS - n. volume 53 - pp. da 190 a 197 ISSN: 0009-8604 [Articolo in rivista (262) - Articolo su rivista]
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.

Medici L.; Brigatti M.F.; Caprilli E.; Malferrari D. ( 2005 ) - Trilithionite-2M2 and Polylithionite-2M2: a Crystal Chemical Study ( Micas @ Italy - Rimini (Italia) - 09-11 febbraio 2005) ( - Book of Abstract ) (Gruppo Nazionale PRIN 2004 - ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Malferrari D.; Benincasa E.; Brigatti M.F.; Guidotti C.V. ( 2005 ) - Trioctahedral and Dioctahedral Micas Coexisting in Metamorphic Sequences from Maine ( Micas @ Italy - Rimini (Italia) - 09-11 febbraio 2005) ( - Book of Abstract ) (Gruppo Nazionale PRIN 2004 - ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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M.F. Brigatti; E. Caprilli; A. Laurora; D. Malferrari; L. Medici; A. Mottana ( 2005 ) - Trioctahedral micas in volcanic rocks from Mt. Sassetto (Tolfa area, Central Italy) ( Geoitalia2005 - V Forum Italiano di Scienze della Terra - Spoleto - 21-23 settembre 2005) ( - Epitome 2005, 1 - Geoitalia2005 ) (FIST Udine ITA ) - EPITOME - n. volume 1 - pp. da 232 a 233 ISSN: 1972-1552 [Abstract in rivista (266) - Abstract in Rivista]
Abstract

Presentazione a poster nella sessione "GEO06- Mineralogia- Mineralogy" tenutasi a Spoleto il 23 settembre 2005 in occasione di Geoitalia 2005

Chu W.S.; Wu Z.Y.; Liu W.H.; Malferrari D.; Brigatti M.F.; Cibin G.; Marcelli A. ( 2005 ) - XANES study of Hg sorption products on montmorillonite at high temperatures - HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION - n. volume 29 - pp. da 84 a 88 ISSN: 0254-3052 [Articolo in rivista (262) - Articolo su rivista]
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.

M.F. Brigatti; D. Malferrari; A. Laurora ( 2004 ) - Controllo dei fattori petrologici sulla cristallochimica delle miche. [Altro (298) - Partecipazione a progetti di ricerca]
Abstract

Brigatti M.F.; Malferrari D.; Medici L.; Ottolini L.; Poppi L. ( 2004 ) - Crystal Chemistry of Apatite Coexisting With Phlogopite and Tetra-Ferryphlogopite ( Tenth International Symposium on Experimental Mineralogy, Petrology and Geochemistry - Frankfurt - 4-7 aprile) ( - Lithos, Supplement to volume 73 ) (Elsevier - NLD ) - LITHOS - n. volume 73 [Abstract in rivista (266) - Abstract in Rivista]
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Brigatti M.F.; Malferrari D.; Medici L.; Ottolini L.; Poppi L. ( 2004 ) - Crystal Chemistry of Apatites from the Tapira carbonatite complex, Brazil - EUROPEAN JOURNAL OF MINERALOGY - n. volume 16 - pp. da 677 a 685 ISSN: 0935-1221 [Articolo in rivista (262) - Articolo su rivista]
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

M. BRIGATTI; MALFERRARI D.; MEDICI L.; POPPI L. ( 2004 ) - “Cu, Cd, Hg and Cu-, Cd-, Hg-cysteine treated montmorillonite and vermiculite crystals: an EXAFS study. ( XII Convegno SILS - Camerino (Italia) - 5-8 luglio 2004) ( - Book of Abstract ) (Società Italiana Luce di Sincrotrone - ITA ) - pp. da 18 a 19 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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M. BRIGATTI; DILILLO M.; MALFERRARI D.; MEDICI L.; POPPI L. ( 2003 ) - Al(urea)63+ and Cr(urea)63+ interactions with vermiculite ( “Euroclay2003” - Modena (Italy) - June 22-26) ( - Book of Abstract ) (Clay Mineral Society Chantilly, Virginia USA ) - pp. da 44 a 45 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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M. BRIGATTI; MALFERRARI D.; MEDICI L.; POPPI L. ( 2003 ) - An EXAFS study on smectites exchanged with organo-metallic complexes ( Euroclay 2003 - Modena (Italy) - June 22-26) ( - Book of Abstract ) (Clay Mineral Society Chantilly, Virginia USA ) - pp. da 45 a 46 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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M.F. BRIGATTI; COLONNA S.; MALFERRARI D.; MEDICI L. ( 2003 ) - Different organo-metallic species following to Hg, Cu and cysteine treatment on montmorillonite ( Joint Congress A.I.C. – S.I.L.S., - Trieste (Italy) - 21-25 luglio 2003) ( - Book of Abstract ) (Associazione Italiana di Cristallografia Ferrara ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Malferrari D.; Medici L.; Poppi L. ( 2003 ) - Effect of amino acids on the retention of copper by beidellite - ENVIRONMENTAL ENGINEERING SCIENCE - n. volume 20(6) - pp. da 601 a 606 ISSN: 1092-8758 [Articolo in rivista (262) - Articolo su rivista]
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.

M. BRIGATTI; MALFERRARI D.; MEDICI L.; POPPI L. ( 2003 ) - EXAFS analysis of montmorillonite and beidellite intercalated with Cu-amino acid complexes: modelling and experiments ( GEOITALIA 2003, 4° Forum Italiano di Scienze della Terra - Bellaria (Italy) - September 16-18) ( - Book of Abstract ) (FIST Udine ITA ) - pp. da 612 a 612 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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M. BRIGATTI; MALFERRARI D.; MEDICI L.; POPPI L. ( 2003 ) - Hg - cysteine complex sorbed by smectites - a combined XRD, TG-MS, and EXAFS study ( "Euroclay2003" - Modena (Italy) - June 22-26) ( - Book of Abstract ) (Clay Mineral Society Chantilly, Virginia USA ) - pp. da 45 a 45 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Malferrari D. ( 2003 ) - Organo-Metallic Complexes and Phyllosilicate - PLINIUS - n. volume 29 - pp. da 47 a 52 ISSN: 1120-317X [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti M.F.; Malferrari D.; Medici L.; Poppi L. ( 2003 ) - Structural and chemical modification induced in rectorite treated with Hg(II), Cd(II) and cysteine ( "Euroclay2003” - Modena (Italy) - June 22-26) ( - Book of Abstract ) (Clay Mineral Society Chantilly, Virginia USA ) - pp. da 46 a 46 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Dilillo M.; Malferrari D.; Medici L.; Poppi L. ( 2003 ) - Structural and chemical modifications of natural vermiculite samples induced by the treatment with Al(urea)63+ and Cr(urea)63+ complexes ( GEOITALIA 2003, 4° Forum Italiano di Scienze della Terra - Bellaria - 16-18 settembre 2003) ( - Book of Abstract ) (Federazione Italiana di Sciende della Terra Udine ITA ) - pp. da 611 a 611 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Malferrari D.; Medici L.; Poppi L. ( 2002 ) - Characterization of Cu-complexes in smectite with different layer charge location: chemical, thermal and EXAFS study ( Clay meeting of France Clay Group - Orleans (France) - 22 marzo 2002) ( - Book of abstract ) (France Clay Group Paris FRA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Malferrari D.; Medici L.; Poppi L. ( 2002 ) - Hg-Cysteine complexes in montmorillonite interlayer ( 18 th General Meeting of the International Mineralogical Association - Edinburgh, Scotland - 1-6 settembre 2002) ( - Book of Abstract ) (IMA - ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Saccardo D.; Benincasa E.; Malferrari D.; Medici L. ( 2002 ) - I minerali di Monte Cengio - RIVISTA MINERALOGICA ITALIANA - n. volume 1 - pp. da 42 a 47 ISSN: 0391-9641 [Articolo in rivista (262) - Articolo su rivista]
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.

M.F. Brigatti; L. Poppi; D. Malferrari ( 2002 ) - LE PROPRIETA' CRISTALLOCHIMICHE DELLE MICHE COME PARAMETRI CONDIZIONANTI L'INTERPRETAZIONE PETROLOGICA [Altro (298) - Partecipazione a progetti di ricerca]
Abstract

Questo progetto di ricerca, pur nella sua durata forzatamente breve, intende dimostrare che:1) I processi naturali che coinvolgono miche sono più comprensibili, meglio interpretabili e più chiaramente modellizzabili se sono considerati in modo congiunto tutti i comportamenti termodinamici che sono collegati con gli aspetti cristallochimici delle miche stesse;2) Lo studio cristallochimico di campioni di miche scelti secondo criteri petrologici consente di dedurre informazioni più compiutamente interpretabili di uno studio che sia basato su campioni scelti secondo altri criteri;3) Su basi cristallochimiche e petrologiche congiunte è possibile prevedere relazioni di stabilità delle miche che possono essere utili anche per il controllo della stabilità di manufatti di valore culturale e per il recupero di situazioni d'inquinamento ambientale.

Brigatti M.F.; Colonna S.; Malferrari D.; Medici L. ( 2002 ) - Metal-organic Cu complexes in smectites with different layer charge location: chemical, thermal and EXAFS study ( 18 th General Meeting of the International Mineralogical Association - Edinburgh, Scotland - 1-6 settembre 2002) ( - Book of Abstracts ) (IMA - ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Benincasa E.; Brigatti M.F.; Franchini G.; Malferrari D.; Medici L.; Poppi L.; Tonelli M. ( 2002 ) - Reactions between Cr(VI) solutions and pyrite: chemical and surface studies - GEOLOGICA CARPATHICA - n. volume 53 (2) - pp. da 1 a 7 ISSN: 1335-0552 [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti M.F.; Benincasa E.; Malferrari D.; Medici L.; Poppi L. ( 2002 ) - Reactions of Zn2+ aqueous solutions with fluor-hydroxyapatite: a crystallographic evidence - NEUES JAHRBUCH FUR MINERALOGIE MONATSHEFTE - n. volume 3 - pp. da 129 a 137 ISSN: 0028-3649 [Articolo in rivista (262) - Articolo su rivista]
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.

E. Benincasa; M.F. Brigatti; D. Malferrari; L. Medici; L. Poppi ( 2002 ) - Sorption of Cd-cysteine complexes by kaolinite - APPLIED CLAY SCIENCE - n. volume 21 - pp. da 191 a 201 ISSN: 0169-1317 [Articolo in rivista (262) - Articolo su rivista]
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.

Brigatti M.F.; Colonna S.; Malferrari D.; Medici L. ( 2002 ) - Structural modifications induced by metal complexation with organic matter in smectites: a multi-analytical approach ( Decimo Convegno S.I.L.S. - Roma - 11-13 luglio 2002) ( - Book of Abstracts ) (SILS - ITA ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Benincasa E.; Brigatti M.F.; Malferrari D.; Medici L.; Poppi L. ( 2001 ) - Kinetics of Cd sorption by kaolinite in presence of sulphur-bearing amino acids ( GEOITALIA 2001, 3° Forum Italiano di Scienze della Terra - Chieti - 5-8 settembre 2001) ( - Book of Abstracts ) (FIST Udine ITA ) - pp. da 650 a 651 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M. F.; Benincasa E.; Malferrari D.; Medici L.; Poppi L. ( 2001 ) - Kinetics of Cr(VI) reduction by Fe(II)-bearing minerals: chemical treatments, X-ray absorption spectroscopy and surface studies. ( MECC ’01 - Starà Lasnà, Slovakia - 9-14 settembre 2001) ( - Abstract volume ) (Mid-European Clay Conference (MECC) - ) - pp. da 21 a 21 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Malferrari D.; Poppi L. ( 2001 ) - Reactions of Hg ions in aqueous solutions with smectite in presence of the amino acid cysteine ( MECC ’01 - Starà Lasnà, Slovakia - 9-14 settembre 2001) ( - Abstract volume ) (Mid-European Clay Conference - ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Benincasa E.; Malferrari D.; Medici L.; Poppi L. ( 2001 ) - Reactions of Pb2+ and Zn2+ aqueous solutions with fluorapatite crystals ( GEOITALIA 2001, 3° Forum Italiano di Scienze della Terra - Chieti - 5-8 settembre 2001) ( - Book of Abstracts ) (FIST Udine ITA ) - pp. da 777 a 777 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Benincasa E.; Malferrari D.; Medici L.; Poppi L. ( 2001 ) - Structural and chemical modifications of natural vermiculite samples induced by the treatment with Cd-ethylenediamine complex ( MECC ’01 - Starà Lasnà, Slovakia - 9-14 settembre 2001) ( - Book of Abstracts ) (Mid-European Clay Conference - ) [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Benincasa E.; Malferrari D.; Medici L.; Poppi L. ( 2001 ) - Structural and chemical modifications of vermiculite crystals induced by Cd-ethylenediamine complex treatment ( GEOITALIA 2001, 3° Forum Italiano di Scienze della Terra - Chieti - 5-8 settembre 2001) ( - Book of Abstract ) (FIST Udine ITA ) - pp. da 653 a 654 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Benincasa E.; Malferrari D.; Medici L.; Poppi L. ( 2001 ) - X-ray absorption spectroscopy of Cu-rich smectites treated with alpha-amino acids ( MECC ’01 - Starà Lasnà, Slovakia - 9-14 settembre 2001) ( - Abstract Volume ) (Mid-European Clay Conference (MECC) - ) - pp. da 23 a 23 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Benincasa E.;Brigatti M.F.; Malferrari D.; Medici. L.; Poppi L. ( 2000 ) - A regular interstratified mica-smectite mineral from micaschist levels of Sesia Lanzo Zone (Italy) ( ADVANCES ON MICAS - CNR & Accademia Nazionale Lincei, Roma - 2-3 novembre) ( - ADVANCES ON MICAS. (Problems, methods, applications in Geodynamics) ) (Accademia Nazionale dei Lincei Roma ITA ) - pp. da 191 a 194 ISBN: 0000000000 ISSN: - [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
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Brigatti M.F.; Malferrari D.; Medici L.; Poppi L. ( 2000 ) - Experimental evidence of Hg and Cu retention by montmorillonite: a combined chemical and XAS study ( - - - - -) ( - Plinius ) (Schweizerbart science publishers Stuttgart DEU ) - PLINIUS - n. volume 24 - pp. da 56 a 57 ISSN: 1120-317X [Abstract in rivista (266) - Abstract in Rivista]
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Benincasa E.; Brigatti M.F.; Malferrari D.; Medici L.; Poppi L.; Vendrame F. ( 2000 ) - Interaction of pyrite surface with Cr(VI) aqueous solutions ( - - - - -) ( - Plinius ) (Schweizerbart Science Publishers Stuttgard DEU ) - PLINIUS - n. volume 24 - pp. da 29 a 31 ISSN: 1120-317X [Abstract in rivista (266) - Abstract in Rivista]
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Benincasa E.; Brigatti M.F.; Malferrari D.; Medici L.; Poppi L. ( 2000 ) - K-rich rectorite from kaolinized micaschists of Sesia-Lanzo zone (Italy) ( - - - - -) ( - Plinius ) (Schweizerbart Science Publishers Stuttgard DEU ) - PLINIUS - n. volume 24 - pp. da 28 a 29 ISSN: 1120-317X [Abstract in rivista (266) - Abstract in Rivista]
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Benincasa E.; Brigatti M.F.; Malferrari D.; Poppi L. ( 2000 ) - XAFS study of Cu sorption products on smectites treated with alpha-amino acids ( Proceedings of the International Congress on Applied Mineralogy - Goettingen, Germany - 17-19 LUGLIO 2000) ( - Applied Mineralogy: In Research, Economy, Technology, Ecology and Culture, Proceedings of the International Congress on Applied Mineralogy ) (Rammlmair, Dieter Goettinge ) - n. volume 2 - pp. da 723 a 726 ISSN: - [Abstract in Atti di convegno (274) - Abstract in Atti di Convegno]
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.