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https://www.readbyqxmd.com/read/30099158/application-of-fuzzy-logic-tools-for-the-biogeochemical-characterisation-of-un-contaminated-waters-from-aljustrel-mining-area-south-portugal
#1
A T Luís, J A Grande, J M Davila, J Aroba, N Durães, S F P Almeida, M L de la Torre, A M Sarmiento, J C Fortes, E Ferreira da Silva, M Santisteban
Aljustrel mining area (South Portugal) belongs to the Iberian Pyrite Belt (IPB). It is classified of high environmental risk due to its large tailings and to the Acid Mine Drainage (AMD) affected waters, generated by sulphides' oxidation. Integrating biological parameters (for the first time) in the input data matrix of the software PreFuRGe, allowed a better discrimination of the diatoms' responses to the stimuli caused by the hydrochemical changes imposed by the processes affecting water quality. Each hydrochemical scenario, was modeled by imposing maximum and minimum limits for each antecedent, according to the conditions imposed by the consequent, which in this case were the number of diatom species and pH...
August 1, 2018: Chemosphere
https://www.readbyqxmd.com/read/30079968/synthesis-of-thin-film-metal-pyrites-by-an-atomic-layer-deposition-approach
#2
Jue Wang, Zheng Guo, Wei Xiong, Xinwei Wang
Late 3d transition-metal disulfides (MS2, M = Fe, Co, Ni, Cu, Zn) can crystallize in an interesting cubic pyrite structure, in which all the metal cations are in a low-spin electronic configuration with progressive increase of the eg electrons for M = Fe ~ Zn. These metal pyrite compounds exhibit very diverse and intriguing electrical and magnetic properties, which have stimulated considerable attention for various applications, especially in the cutting-edge energy conversion and storage technologies. The synthesis of the metal pyrites is certainly very important, because highly controllable, reproducible, and reliable synthesis methods are virtually essential for both fundamental materials research and practical engineering...
August 6, 2018: Chemistry: a European Journal
https://www.readbyqxmd.com/read/30076195/automated-microscopical-analysis-of-metal-sulfide-colonization-by-acidophilic-microorganisms
#3
Sören Bellenberg, Antoine Buetti-Dinh, Vanni Galli, Olga Ilie, Malte Herold, Stephan Christel, Mariia Boretska, Igor V Pivkin, Paul Wilmes, Wolfgang Sand, Mario Vera, Mark Dopson
Industrial biomining processes are currently focused on metal sulfides and their dissolution, which is catalyzed by acidophilic iron(II)-and/or sulfur-oxidizing microorganisms. Cell attachment on metal sulfides is important for this process. Biofilm formation is necessary for seeding and persistence of the active microbial community in industrial biomining heaps and tank reactors and enhances metal release. In this study, we used a method for direct quantification of the mineral-attached cell population on pyrite or chalcopyrite particles in bioleaching experiments by coupling high-throughput, automated epifluorescence microscopy imaging of mineral particles with algorithms for image analysis and cell quantification, avoiding human bias in cell counting...
August 3, 2018: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/30064871/biomarker-responses-of-the-freshwater-clam-corbicula-fluminea-in-acid-mine-drainage-polluted-systems
#4
Estefanía Bonnail, Ricardo Cunha Lima, Esther Bautista-Chamizo, María José Salamanca, Pablo Cruz-Hernández
The environmental quality of an acid mine drainage polluted river (Odiel River) in the Iberian Pyrite Belt (SW Spain) was assessed by combining analyses of biomarkers (DNA strand breaks, LPO, EROD, GST, GR, GPx) in freshwater clams (Corbicula fluminea) exposed during 14 days and correlated with metal(loid) environmental concentrations. Results pointed that enzymatic systems are activated to combat oxidative stress in just 24 h. Along exposure, there were homeostatic regulations with the glutathione activity that influenced in lipid peroxidation oscillations, provoking significant DNA strand damage after 14 exposure days...
July 24, 2018: Environmental Pollution
https://www.readbyqxmd.com/read/30041392/spatial-distribution-of-hydrogen-sulfide-and-sulfur-species-in-coastal-marine-sediments-hiroshima-bay-japan
#5
Satoshi Asaoka, Akira Umehara, Sosuke Otani, Naoki Fujii, Tetsuji Okuda, Satoshi Nakai, Wataru Nishijima, Koji Takeuchi, Hiroshi Shibata, Waqar Azeem Jadoon, Shinjiro Hayakawa
This study aims to reveal spatial distribution of hydrogen sulfide and sulfur species in marine sediments in Hiroshima Bay, Japan, by direct analyses using a combination of detection tubes and X-ray absorption fine structure spectroscopy. In summer and autumn, the hydrogen sulfide concentration ranged from <0.1 to 4 mg-S L-1 . In this study, only hydrogen sulfide was observed in autumn and at two stations in summer. In contrast, some earlier studies reported in all seasons in Hiroshima Bay the presence of acid volatile sulfide, which is used as a proxy of sulfide content...
August 2018: Marine Pollution Bulletin
https://www.readbyqxmd.com/read/30026576/neandertal-fire-making-technology-inferred-from-microwear-analysis
#6
A C Sorensen, E Claud, M Soressi
Fire use appears to have been relatively common among Neandertals in the Middle Palaeolithic. However, the means by which Neandertals procured their fire-either through the collection of natural fire, or by producing it themselves using tools-is still a matter of debate. We present here the first direct artefactual evidence for regular, systematic fire production by Neandertals. From archaeological layers attributed to late Mousterian industries at multiple sites throughout France, primarily to the Mousterian of Acheulean Tradition (MTA) technoculture (ca...
July 19, 2018: Scientific Reports
https://www.readbyqxmd.com/read/30019202/reactive-transport-of-arsenic-enriched-geothermal-spring-water-into-a-sedimentary-aquifer
#7
Chen-Wuing Liu
The movement of high-arsenic (As)-concentration Beitou geothermal spring water up to 4600 μg/L from the upstream area may affect the downstream Guandu plain and Guandu wetland. The major As pathway is via the subsurface flow. The study assesses the fate and transport of As-enriched geothermal spring water in the Beitou-Guandu area. The groundwater head and flow field velocity are first simulated by using HYDROGEOCHEM-fluid flow model. The steady state flow field is well-calibrated with root mean square error 1...
July 17, 2018: Environmental Geochemistry and Health
https://www.readbyqxmd.com/read/30017363/relationships-between-galvanic-interaction-copper-extraction-and-community-dynamics-during-bioleaching-of-chalcopyrite-by-a-moderately-thermophilic-culture
#8
Yuguang Wang, Xinhua Chen, Hongbo Zhou
A moderately thermophilic culture was enriched and adapted to bioleach chalcopyrite at high pulp density. In order to further improve copper extraction, effects of galvanic interaction on bioleaching performance and community dynamics were investigated by adding pyrite. Copper extractions were improved by 2.91 and 1.97 times in the initial and the final stages when pyrite was present, respectively. However, it did not benefit chalcopyrite dissolution in the middle stage. Community dynamics analysis showed that succession of the attached cells was significantly different from community dynamics of the planktonic cells...
October 2018: Bioresource Technology
https://www.readbyqxmd.com/read/29965418/-molecular-research-of-acid-generating-microbial-communities-in-abandoned-ores-in-the-waste-dump-of-an-iron-mine-in-anhui-province
#9
Ze-Rui Du, Chun-Bo Hao, Li-Xin Pei, Peng-Fei Wei, Yi Zhang, Yan-Chun Lu
The waste dump of an iron mine in Anhui Province has been abandoned for several decades. Pyrite in the exposed waste ores is oxidized by acidophiles and large amounts of metal ions and H2 SO4 are released, resulting in the formation of an acid mine drainage (AMD) lake since 1970s. Besides the lake, there are also some small-scale AMD adjacent to the newly deposited waste ore. In order to study the acid generation potential of the waste ore and the related microbial communities, soil samples were taken from beside the AMD lake (1LL) and small-scale AMD (5J, 5Y, 6-1, 6-2, 6-3) and the physicochemical properties and microbial community of these samples were analyzed...
November 8, 2017: Huan Jing Ke Xue= Huanjing Kexue
https://www.readbyqxmd.com/read/29965257/-mechanism-of-photochemical-degradation-of-mc-lr-by-pyrite
#10
Wei Zhou, Yan-Fen Fang, Yu Zhang, Chun-Hong Wu, Ying-Ping Huang
Pyrite was used as catalyst to degrade Microcystin-LR (MC-LR) at pH 6.8 under visible light irradiation ( λ >420 nm). X-ray diffraction (XRD) and scanning electron microscope (SEM) characterization showed that pyrite had the layered structure. The ion state of pyrite before and after the reaction was identified using X-Ray Photoelectron Spectroscopy (XPS), confirming the conversion process of Fe(Ⅱ) to Fe(Ⅲ) on the sulfur defect sites. Electron Spin Resonance (ESR) test showed that pyrite photochemical reaction produced hydroxyl radical (·OH)...
September 8, 2017: Huan Jing Ke Xue= Huanjing Kexue
https://www.readbyqxmd.com/read/29949367/restricted-open-shell-configuration-interaction-singles-study-on-m-and-l-edge-x-ray-absorption-spectroscopy-of-solid-chemical-systems
#11
Adam Kubas, Max Verkamp, Josh Vura-Weis, Frank Neese, Dimitrios Maganas
In this study the M- and L-edge X-ray absorption spectra of a series of open- and closed-shell solids (TiO2 rutile, α-Fe2 O3 hematite, FeS2 pyrite, and the spinel Co3 O4 ) are investigated with the restricted open-shell configuration interaction singles methods (ROCIS/DFT and PNO-ROCIS/DFT) using the embedded cluster approach. ROCIS/DFT type of methods are grounded in wave function-based ab initio electronic structure theory and have shown great performance in the field of X-ray spectroscopy in particular in the field of transition metal L-edge spectroscopy...
July 16, 2018: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/29947123/unprecedented-34-s-enrichment-of-pyrite-formed-following-microbial-sulfate-reduction-in-fractured-crystalline-rocks
#12
Henrik Drake, Martin J Whitehouse, Christine Heim, Peter W Reiners, Mikael Tillberg, K Johan Hogmalm, Mark Dopson, Curt Broman, Mats E Åström
In the deep biosphere, microbial sulfate reduction (MSR) is exploited for energy. Here, we show that, in fractured continental crystalline bedrock in three areas in Sweden, this process produced sulfide that reacted with iron to form pyrite extremely enriched in 34 S relative to 32 S. As documented by secondary ion mass spectrometry (SIMS) microanalyses, the δ34 Spyrite values are up to +132‰V-CDT and with a total range of 186‰. The lightest δ34 Spyrite values (-54‰) suggest very large fractionation during MSR from an initial sulfate with δ34 S values (δ34 Ssulfate,0 ) of +14 to +28‰...
June 27, 2018: Geobiology
https://www.readbyqxmd.com/read/29934829/mobility-and-natural-attenuation-of-metals-and-arsenic-in-acidic-waters-of-the-drainage-system-of-timok-river-from-bor-copper-mines-serbia-to-danube-river
#13
Stefan Đorđievski, Daizo Ishiyama, Yasumasa Ogawa, Zoran Stevanović
Bor, Krivelj, and Bela Rivers belong to the watershed of Timok River, which is a tributary of transboundary Danube River. These rivers receive metal-rich acidic wastewater from metallurgical facilities and acid mine drainage (AMD) from mine wastes around Bor copper mines. The aim of this study was to determine the mobility and natural attenuation of metals and arsenic in rivers from Bor copper mines to Danube River during the year 2015. The results showed that metallurgical facilities had the largest impact on Bor River by discharging about 400 t of Cu per year through highly acidic wastewater (pH = 2...
June 22, 2018: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/29934531/sulfidation-mechanism-of-zno-roasted-with-pyrite
#14
Wei Liu, Lin Zhu, Junwei Han, Fen Jiao, Wenqing Qin
Sulfidation is a widely used technology to improve the floatability of oxidized metal minerals or to stabilize the heavy metals in various wastes. The sulfidation mechanism of ZnO with pyrite was detailedly studied by thermodynamic calculation and roasting experiments. The sulfidation behaviors, phase transformations, microscopic morphology and surface properties were investigated by TG-DSC, ICP, XRD, SEM-EDS, and XPS analysis. The results indicate that the nature of the sulfidation is the reaction of ZnO with the gaseous sulfur generated by the decomposition of pyrite...
June 22, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29933164/composition-and-risk-assessment-of-roasted-pyrite-ash-from-fertiliser-production
#15
M Gabarrón, O Babur, J M Soriano-Disla, A Faz, J A Acosta
Pyrite ash is a residue from the roasting of pyrite ores to obtain sulphuric acid used in the fertiliser industry and its production is widely extended worldwide. The mismanagement of this waste may result in environmental and health damages due to its physico-chemical characteristics. The main objective of this study was to examine the physico-chemical and mineralogical composition of roasted pyrite ash from an abandoned fertiliser company, and to evaluate the environmental risk caused by the wind and water dispersion of metals posed by this waste...
June 18, 2018: Chemosphere
https://www.readbyqxmd.com/read/29932156/flash-smelting-copper-concentrates-spectral-emission-measurements
#16
Luis Arias, Sergio Torres, Carlos Toro, Eduardo Balladares, Roberto Parra, Claudia Loeza, Camilo Villagrán, Pablo Coelho
In this paper, we report on spectral features emitted by a reaction shaft occurring in flash smelting of copper concentrates containing sulfide copper minerals such as chalcopyrite (CuFeS₂), bornite (Cu₅FeS₄) and pyrite (FeS₂). Different combustion conditions are addressed, such as sulfur-copper ratio and oxygen excess. Temperature and spectral emissivity features are estimated for each case by using the two wavelength method and radiometric models. The most relevant results have shown an increasing intensity behavior for higher sulfur-copper ratios and oxygen contents, where emissivity is almost constant along the visible spectrum range for all cases, which validates the gray body assumption...
June 22, 2018: Sensors
https://www.readbyqxmd.com/read/29929220/unraveling-the-impact-of-chronic-exposure-to-metal-pollution-through-human-gallstones
#17
Annika Parviainen, Claudio Marchesi, Juan Manuel Suárez-Grau, Carlos J Garrido, Rafael Pérez-López, José Miguel Nieto, Gema Cobo-Cárdenas
This study aims to explore the impact of chronic metal exposure derived from persistent pollution from mining activity using human gallstones as proxies. The samples were obtained from patients residing in geologically and environmentally contrasting areas in the Province of Huelva, SW Spain, allowing for the evaluation of the regional effect of metal pollution. The study group resides in the Iberian Pyrite Belt characterized by natural and anthropogenic metal pollution from mining activities, whereas the control group resides in the Ossa Morena Zone famous for its natural parks...
May 15, 2018: Science of the Total Environment
https://www.readbyqxmd.com/read/29929075/optical-microscopy-as-a-new-approach-for-characterising-dust-particulates-in-urban-environment
#18
Silvie Koval, Gregoire Krahenbuhl, Karryn Warren, Graham O'Brien
In urban environments airborne particulates (dust) must be managed to ensure that industry and community coexist in a mutually beneficial and sustainable manner. The composition of the dust is a function of the local environment and industry. In general, there is a view by many community members that a significant proportion of inhalable (PM10 ) and respirable (PM2.5 ) dust in these environments could be coal. Thus there is a need to have an analytical method that provides a quantitative analysis of the amount and size distribution of the different particulates that can be present in air samples...
June 18, 2018: Journal of Environmental Management
https://www.readbyqxmd.com/read/29923673/unusual-microbial-mat-related-structural-diversity-2-1-billion-years-ago-and-implications-for-the-francevillian-biota
#19
Jérémie Aubineau, Abderrazak El Albani, Ernest Chi Fru, Murray Gingras, Yann Batonneau, Luis A Buatois, Claude Geffroy, Jérôme Labanowski, Claude Laforest, Laurent Lemée, Maria G Mángano, Alain Meunier, Anne-Catherine Pierson-Wickmann, Philippe Recourt, Armelle Riboulleau, Alain Trentesaux, Kurt O Konhauser
The 2.1-billion-year-old (Ga) Francevillian series in Gabon hosts some of the oldest reported macroscopic fossils of various sizes and shapes, stimulating new debates on the origin, evolution and organization of early complex life. Here, we document ten representative types of exceptionally well-preserved mat-related structures, comprising "elephant-skin" textures, putative macro-tufted microbial mats, domal buildups, flat pyritized structures, discoidal microbial colonies, horizontal mat growth patterns, wrinkle structures, "kinneyia" structures, linear patterns and nodule-like structures...
June 20, 2018: Geobiology
https://www.readbyqxmd.com/read/29904798/the-impact-of-preload-on-the-mobilisation-of-multivalent-trace-metals-in-pyrite-rich-sediment
#20
O Karikari-Yeboah, W Skinner, J Addai-Mensah
Trace metals occur at various concentrations in all wetlands. Their proliferation, chemical speciation, mobility and bioavailability are dependent on the redox potential (Eh), pH and the presence of organic and inorganic adsorption surfaces and co-precipitating metals. Consequently, changes in these key parameters have the potential to alter the fate of the dominant trace metal species in the sediment. An imposition of preload surcharge is a technique use in geotechnical engineering to improve in the strength and load carrying capacity of waterlogged sediments...
June 14, 2018: Environmental Monitoring and Assessment
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