Different ratios of solid binary mixtures of quartz, calcite, kaolinite, and illite were prepared by analytical balance: 5/95, 25/75, 50/50, 75/25, 95/5. These powder mixtures were analyzed using a Rigaku Rint 2200 instrument with a... more
Different ratios of solid binary mixtures of quartz, calcite, kaolinite, and illite were prepared by analytical balance: 5/95, 25/75, 50/50, 75/25, 95/5. These powder mixtures were analyzed using a Rigaku Rint 2200 instrument with a conventional Bragg-Brentano geometry equipped with a copper tube and a graphite crystal monochromator. The data were collected in the angular range 3-100 2θ with steps of 0.02 and 5 s/step. The data collections were converted into GSAS files for EXPGUI software and quantitatively refined by Rietveld method. These refinements and weight amounts were used as references for the following data collections.
Research Interests:
Research Interests:
This paper presents a microbeam (electron microprobe, Raman spectroscopic and X-ray microdiffraction) study of cancrinite-group minerals of relevance to alkaline igneous rocks. A solid solution is known to exist between cancrinite and... more
This paper presents a microbeam (electron microprobe, Raman spectroscopic and X-ray microdiffraction) study of cancrinite-group minerals of relevance to alkaline igneous rocks. A solid solution is known to exist between cancrinite and vishnevite with the principal substitutions being CO3 2- by SO4 2- and Ca for Na. In the present study, several intermediate members of the cancrinite–vishnevite series from a syenitic intrusion at Cinder Lake (Manitoba, Canada), were used to examine how chemical variations in this series affect their spectroscopic and structural characteristics. The Cinder Lake samples deviate from the ideal cancrinite-vishnevite binary owing to the presence of cation vacancies. The only substituent elements detectable by electron microprobe are K, Sr and Fe (0.03-0.70, 0-0.85 and 0-0.45 wt.% respective oxides). The following Raman bands are present in the spectra of these minerals: ∼631 cm-1 and ∼984-986 cm-1 [SO4 2- vibration modes]; ∼720-774 cm -1 and ∼1045-1060 cm...
Research Interests: Geology()
()
Research Interests:
Research Interests:
... crystal chemistry and XANES spectroscopy Maria Franca BRIGATTI 1 ,* , Ermanno GALLI 1 , Luca MEDICI 1 , Luciano POPPI 1 ... A sample occurs within biotite schist at Campbell Creek, whereas the other sample occurs in mica layers of a... more
... crystal chemistry and XANES spectroscopy Maria Franca BRIGATTI 1 ,* , Ermanno GALLI 1 , Luca MEDICI 1 , Luciano POPPI 1 ... A sample occurs within biotite schist at Campbell Creek, whereas the other sample occurs in mica layers of a quartz-schist at Anatoki River Go ...
Research Interests:
ABSTRACT Combinations of different molecules usually co-exuded by plant roots in soil can significantly affect the mobilization of mineral elements from soil. The flavonoids rutin and quercetin appeared to be highly efficient in Fe and Mn... more
ABSTRACT Combinations of different molecules usually co-exuded by plant roots in soil can significantly affect the mobilization of mineral elements from soil. The flavonoids rutin and quercetin appeared to be highly efficient in Fe and Mn mobilization from soil, being rutin about 25 times more effective than citrate in extracting Fe from an alkaline calcareous soil, and 15 times in mobilizing Mn from a slight acidic agricultural soil. Quercetin was particularly effective in mobilizing Mn from the acidic soil and 50 times more efficient than citrate. A significant synergistic effect was detected when either quercetin or rutin was combined with citrate, extracting, respectively, 1.7 and 1.5 times more Mn than what is expected by a simple combination of the two. Sorption processes on soil particles were more relevant for flavonoids than for organic acids for which microbial degradation often prevails, with the only exception of oxalate. Citrate was usually the most efficient organic acid in mobilizing major and trace elements from soil even if oxalate was a better extractant for Cu, Zn, and Ni from the alkaline soil. In the acid soil, a synergistic effect among organic acids was observed only for Mn while in alkaline soil it was observed for Si. The mechanism by which Fe is extracted by rutin in the alkaline soil is a reductive one, with one molecule of rutin being capable of mobilizing two atoms of Fe. Also for Mn in the acid soil, quercetin and rutin solubilize this element by a reductive process. However, when quercetin and rutin are combined with citrate, a complex-forming dissolution mechanism also occurs which increases the mobilization of Mn over the expected rates.
Research Interests:
Research Interests:
Research Interests:
ABSTRACT
ABSTRACT
... Spagnuolo 1 , Bart Vekemans 2 , Laszlo Vincze 3 , Luca Medici 4 , Koen Janssens 2 , Fabio Tateo 5 , and Pacifico Ruggiero 1 ... By using different spectroscopic techniques such as Electron Spin Resonance (ESR), Fourier-Transformed... more
... Spagnuolo 1 , Bart Vekemans 2 , Laszlo Vincze 3 , Luca Medici 4 , Koen Janssens 2 , Fabio Tateo 5 , and Pacifico Ruggiero 1 ... By using different spectroscopic techniques such as Electron Spin Resonance (ESR), Fourier-Transformed Infra-Red (FT-IR) spectroscopy, and micro X ...
ABSTRACT
Research Interests: Geology()
()
Research Interests:
ABSTRACT Poster
An extremely severe aspect, both from environmental and economic viewpoint, is the management of polluted sediments removed from drainage and irrigation canals. Canals, in order to retain their functionality over the time, need to have... more
An extremely severe aspect, both from environmental and economic viewpoint, is the management of polluted sediments 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 removed sediments is extremely demanding, also from an economical perspective, if these latter needs to be treated as dangerous waste materials, as stated in numerous international standards. Furthermore the disposal of such a large amount of material may introduce a significant environmental impact as well. An appealing alternative is the recovery or reuse of these materials, for example in brick and tile industry, after obviously the application of appropriate techniques and protocols that could render these latter no longer a threat for human health. The assessment of the effective potential danger for human health and ecosystem of sediments before and after treat...
The qualitative and quantitative analyses of crystalluria have clinical significance in the diagnosis and prognosis of urolithiasis. The aim of this paper is to provide a new accurate methodology to get qualitative and quantitative data... more
The qualitative and quantitative analyses of crystalluria have clinical significance in the diagnosis and prognosis of urolithiasis. The aim of this paper is to provide a new accurate methodology to get qualitative and quantitative data on urine particulate in patients with renal stone disease.The procedure involves a urine collection, the separation of the solid residual by centrifugation, and its analysis by X-ray diffraction, utilizing a micro-diffractometer in order to analyze very low amounts of residual. The spectrum obtained was converted into 2 θ -I profiles and quantitatively refined by Rietveld method. The proposed methodology has the advantage to accurately quantify all crystalline phases and the amorphous component of the urine; anyway urine samples have to be centrifuged and analysed as soon as possible, because the quantitative results obtained by the X-ray microdiffraction showed that after some days and at room temperature urine increased significantly both amorphous...
Research Interests:
ABSTRACT A clean and cheap procedure for the synthesis of zeolites is presented, using glass and aluminum wastes as starting materials. The products are aluminosilicate materials with a high cation exchange capacity (CEC: 259–389.5... more
ABSTRACT A clean and cheap procedure for the synthesis of zeolites is presented, using glass and aluminum wastes as starting materials. The products are aluminosilicate materials with a high cation exchange capacity (CEC: 259–389.5 meq/100 g) containing 25–30% of crystalline zeolites. Since the synthesized materials are free of potentially toxic elements, they could be safely used for environmental and agricultural applications. More specifically, a material containing 30% of zeolite A has been synthesized at 60 °C in one week, using NaOH as mineralizing agent. About 15% of zeolite A has been obtained at room temperature in 6 months. When KOH was employed, 25% of edingtonite has been produced in the final material after 1 week at 90 °C. All the materials have been characterized for crystallinity, crystal morphology, particle size, pore size, surface area, and CEC. The whole process has been designed with the aim to recycle useful waste materials and reduce at minimum energy consumption and the production of harmful greenhouse gases.
Research Interests:
In this research, mercury speciation was assessed for soil samples collected inside and outside an industrial polluted area of National environmental interest located in "Val Basento"... more
In this research, mercury speciation was assessed for soil samples collected inside and outside an industrial polluted area of National environmental interest located in "Val Basento" (Basilicata, Italy). Hg concentration in these soil samples ranged from 12 up to 240 mg/kg. Mercury chemical forms in these samples were identified by a combination of sequential extraction procedures, thermal desorption analyses, and
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
ABSTRACT
Research Interests:
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... more
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.
Research Interests:
ABSTRACT
Research Interests:
Research Interests: Engineering, Kinetics, Mass Spectrometry, X ray absorption spectroscopy, Clay Minerals, and 19 moreAdsorption, Temperature, Hazardous Materials, Data Collection, Chemical Analysis, Powder X-Ray Diffraction, Bentonite, Cadmium, Thermal Analysis, X ray diffraction, Hazardous, Spectrum analysis, Thermal Decomposition, Atomic Absorption Spectrophotometry, Amino Acid Profile, Atomic Absorption, Cysteine, X ray Absorption, and Aqueous Solution(Adsorption, Temperature, Hazardous Materials, Data Collection, Chemical Analysis, Powder X-Ray Diffraction, Bentonite, Cadmium, Thermal Analysis, X ray diffraction, Hazardous, Spectrum analysis, Thermal Decomposition, Atomic Absorption Spectrophotometry, Amino Acid Profile, Atomic Absorption, Cysteine, X ray Absorption, and Aqueous Solution)
(Adsorption, Temperature, Hazardous Materials, Data Collection, Chemical Analysis, Powder X-Ray Diffraction, Bentonite, Cadmium, Thermal Analysis, X ray diffraction, Hazardous, Spectrum analysis, Thermal Decomposition, Atomic Absorption Spectrophotometry, Amino Acid Profile, Atomic Absorption, Cysteine, X ray Absorption, and Aqueous Solution)
Diverse analytical techniques are available to determine the particle size distribution of potentially toxic elements in matrices of environmental interest such as soil, sediments, freshwater and groundwater. However, a single technique... more
Diverse analytical techniques are available to determine the particle size distribution of potentially toxic elements in matrices of environmental interest such as soil, sediments, freshwater and groundwater. However, a single technique is often not exhaustive enough to determine both particle size distribution and element concentration. In the present work, the investigation of mercury in soil samples collected from a polluted industrial site was performed by using a new analytical approach which makes use of sedimentation field-flow fractionation (SdFFF) coupled to cold vapour generation electrothermal atomic absorption spectroscopy (CV-ETAAS). The Hg concentration in the SdFFF fractions revealed a broad distribution from about 0.1 to 1 μm, roughly following the particle size distributions, presenting a maximum at about 400-700 nm in diameter. A correlation between the concentration of Hg in the colloidal fraction and organic matter (O.M.) content in the soil samples was also found. However, this correlation is less likely to be related to Hg sorption to soil O.M. but rather to the presence of colloidal mercuric sulfide particles whose size is probably controlled by the occurrence of dissolved O.M. The presence of O.M. could have prevented the aggregation of smaller particles, leading to an accumulation of mercuric sulfides in the colloidal fraction. In this respect, particle size distribution of soil samples can help to understand the role played by colloidal particles in mobilising mercury (also as insoluble compounds) and provide a significant contribution in determining the environmental impact of this toxic element.
Research Interests:
Research Interests:
Research Interests:
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... more
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.
Research Interests:
Research Interests:
Research Interests: Environmental Science, Carbon, Agriculture, Coal, Multidisciplinary, and 18 moreSynchrotron Radiation, Environmental science and technology, Zeolites, X Rays, New Technology, Copper, Heavy Metal, Temperature, Sequential Extraction, Fly Ash, Spatial Distribution, Particulate Matter, Coal Fly Ash, X ray Fluorescence, Environmental, Soil Pollutants, Coal ash, and Agricultural Soil(Synchrotron Radiation, Environmental science and technology, Zeolites, X Rays, New Technology, Copper, Heavy Metal, Temperature, Sequential Extraction, Fly Ash, Spatial Distribution, Particulate Matter, Coal Fly Ash, X ray Fluorescence, Environmental, Soil Pollutants, Coal ash, and Agricultural Soil)
(Synchrotron Radiation, Environmental science and technology, Zeolites, X Rays, New Technology, Copper, Heavy Metal, Temperature, Sequential Extraction, Fly Ash, Spatial Distribution, Particulate Matter, Coal Fly Ash, X ray Fluorescence, Environmental, Soil Pollutants, Coal ash, and Agricultural Soil)
Research Interests:
Research Interests:
Research Interests:
Page 1. 980 V. Summa et al. Copyright © 2006 John Wiley & Sons, Ltd. Earth Surf. Process. Landforms 32, 980–997 (2007) DOI: 10.1002/esp Earth Surface Processes and Landforms Earth Surf. Process. Landforms 32, 980–997 ...