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Keyi Chen, Ye Zhang, Chilin Li
Metal-polysulfide batteries are attracting broad attentions as conversion reaction systems of high theoretical energy density and low cost. However, their further applications are hindered by low loading of active species, excess conductive additive and loose (nanostructured) electrode network. Herein, we propose that compact grain stacking and surface fluorination are two crucial factors for achieving high-rate and long-life pyrite (FeS2) cathode enabled by sulfurating ionic liquid wrapped open framework fluorides...
December 5, 2018: ACS Nano
Rodrigo F Embile, Ingar F Walder, Christopher Schuh, Jenna Lee Donatelli
Metal release from the deposition of sulfide-containing tailings in seawater was investigated using a batch reaction experiment inside a temperature and dissolved oxygen-controlled chamber. Two hundred grams of tailings from a porphyry Cu-Au and a sediment-hosted Cu deposit were submerged in 1.8 L synthetic seawater. The sulfides present in the porphyry Cu-Au tailings are pyrite (FeS2 ), chalcopyrite (CuFeS2 ) and bornite (Cu5 FeS4 ) while in the sediment-hosted Cu tailings are bornite, chalcocite (Cu2 S) and covellite (CuS)...
December 2018: Marine Pollution Bulletin
Junhao Qin, Chuxia Lin, Hamad Almebayedh, Meshari Albader
Batch experiments were conducted to examine the effects of ferrous iron source, soil salinity and temperature on degradation of long-chain petroleum hydrocarbons by Fenton-like processes. The results show that over 70%, 50% and 25% of aliphatic C16-C21, C21-C35 and C35-C40, respectively, was eliminated at a H2 O2 dose of 1.5%. The decomposition rate of petroleum hydrocarbons was similar to each other for ferrous sulfate and magnetite while the capacity of pyrite to trigger Fenton-driven decomposition of long-chain aliphatic petroleum hydrocarbons was weaker, as compared to ferrous sulfate and magnetite...
November 28, 2018: Ecotoxicology and Environmental Safety
Zdzisław M Migaszewski, Agnieszka Gałuszka, Sabina Dołęgowska
The Wiśniówka rock strip mining area (south-central Poland) with quartzite quarries, acid water bodies and tailings piles is one of the most unique acid mine drainage (AMD) sites throughout the world. This is due to the occurrence of enormous amounts of pyrite unknown in sedimentary formations worldwide. Of the two mineralization zones, one that is the most abundant in arsenical pyrite occurs in the lowermost Upper Cambrian formation of the Podwiśniówka quarry. The As-rich pyritiferous clastic rocks are exposed as a result of deep quartzite extraction during 2013-2014...
January 2019: Environmental Pollution
Soroush Modabberi
Muteh Gold Deposit is the biggest active gold district in Iran consisting of two mines, Senjedeh and Chah-Khatoun, and seven mineral occurrences. Senjedeh has been mined about 20 years ago and was recently closed because of the depletion of the reserves. Chah-Khatoun went into operation few years ago. During the previous decades, more than 22 Mt of low-grade wastes has been produced from both mines. The wastes are assumed to be a possible source of gold, especially with recent increase in the world gold prices...
November 19, 2018: Environmental Monitoring and Assessment
Dorota Makowska, Andrzej Strugała, Faustyna Wierońska, Martyna Bacior
The aim of the study was to evaluate the content, occurrence, and leachability of arsenic (As), lead (Pb), and thallium (Tl) in wastes from coal cleaning processes with respect to the safe management of this waste. The study focused on wastes resulting from the wet gravitation and flotation processes employed for the purposes of coking coal cleaning in four coal mines situated in the Upper Silesian Coal Basin (Poland). The scope of the study included (i) determination of the content of these elements in the investigated wastes using atomic absorption spectrometry, (ii) evaluation of their mode of occurrence using electron microprobe analysis, and (iii) preliminary assessment of their leachability in deionized water...
November 13, 2018: Environmental Science and Pollution Research International
Henning Prommer, Jing Sun, Lauren Helm, Bhasker Rathi, Adam J Siade, Ryan Morris
Coal seam gas (CSG) extraction generates large volumes of coproduced water. Injection of the excess water into deep aquifers is often the most sustainable management option. However, such injection risks undesired sediment-water interactions that mobilize metal(loid)s in the receiving aquifer. This risk can be mitigated through pretreatment of the injectant. Here, we conducted a sequence of three push-pull tests (PPTs) where the injectant was pretreated using acid amendment and/or deoxygenation to identify the processes controlling the fate of metal(loid)s and to understand the treatment requirements for large-scale CSG water injection...
November 14, 2018: Environmental Science & Technology
Behzad Vaziri Hassas, Jiaqi Jin, Liem X Dang, Xuming Wang, Jan D Miller
Recently, it was reported that using CO2 as a flotation gas increases the flotation of auriferous pyrite from high carbonate gold ores of the Carlin Trend. In this regard, the influence of CO2 on bubble attachment at fresh pyrite surfaces was measured in the absence of collector using an induction timer, and it was found that nitrogen bubble attachment time was significantly reduced from 30 ms to less than 10 ms in CO2 saturated solutions. Details of CO2 bubble attachment at a fresh pyrite surface have been examined by atomic force microscopy (AFM) measurements and molecular dynamics (MD) simulations, and the results used to describe the subsequent attachment of a N2 bubble...
November 12, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Qian Li, Thomas Becker, Ruiyong Zhang, Tangfu Xiao, Wolfgang Sand
Bacterial adhesion is a key step to prevent environmental problems called acid mine drainage or to improve leaching efficiency in industry, since it initiates and enhances bioleaching. Thus, to analyze bacterial adhesion and to understand this process is crucial. In this study atomic force microscopy equipped with a pyrite or chalcopyrite tip was applied to study the adhesion of Sulfobacillus thermosulfidooxidans. The results illustrate that planktonic cells of both pyrite- and sulfur-grown cells of S. thermosulfidooxidans show more affinity to pyrite than to chalcopyrite (adhesion forces 2 nN versus 0...
October 19, 2018: Colloids and Surfaces. B, Biointerfaces
Santos Galvez-Martinez, Eva Mateo-Marti
We characterized the adsorption of triglycine molecules on a pyrite surface under several simulated environmental conditions by X-ray photoemission spectroscopy. The triglycine molecular adsorption on a pyrite surface under vacuum conditions (absence of oxygen) shows the presence of two different states for the amine functional group (NH₂ and NH₃⁺), therefore two chemical species (anionic and zwitterionic). On the other hand, molecular adsorption from a solution discriminates the NH₂ as a unique molecular adsorption form, however, the amount adsorbed in this case is higher than under vacuum conditions...
October 25, 2018: Life
Zhibin Ge, Dongyang Wei, Jing Zhang, Junsong Hu, Zhuo Liu, Ruihua Li
The searches for suitable substrates with high capacity for phosphorus (P) removal and promoting denitrification for enhancing nitrogen (N) removal have been a key work in constructed wetlands (CWs) research in the past several decades. But few substrates enhancing simultaneous long-term N and P removal in CWs have been found before. In this study, two subsurface flow pilot-scale wetlands using natural pyrite and limestone as substrates were constructed. After 3 year of operation, we found that pyrite had no negative effects on growth of reeds, removals of chemical oxygen demand (COD) and ammonia nitrogen (NH4 + -N), but enhanced long-term total nitrogen (TN) and total phosphorus (TP) removals in constructed wetland...
October 19, 2018: Water Research
M García-Carmona, H García-Robles, C Turpín Torrano, E Fernández Ondoño, J Lorite Moreno, M Sierra Aragón, F J Martín Peinado
No abstract text is available yet for this article.
February 15, 2019: Science of the Total Environment
Matthew D Fischer, Emmanuel Mgboji, Zhongchi Liu
Background: Insertion of engineered DNA fragments into bacterial vectors is the foundation of recombinant DNA technology, yet existing methods are still laborious, require many steps, depend on specific vector configuration, or require expensive reagents. Results: We have developed a method, called "Pyrite" cloning that combines the traditional restriction enzyme digestion and ligation reaction in a single tube and uses a programmed thermocycler reaction, allowing rapid and flexible cloning in a single tube...
2018: Plant Methods
Youngho Sihn, Sungjun Bae, Woojin Lee
We developed a novel solidification and stabilization process using a nanoscale zerovalent iron (NZVI)-cement system for reductive immobilization of hexavalent uranium (U(VI)) in a soil-cement matrix. The NZVI suspension without cement demonstrated high removal efficiency (100% in 2 h) and fast removal kinetics (53.7 Lm-2 d-1 ), which surpassed those of other Fe-containing minerals (i.e., green rust, mackinawite, magnetite, and pyrite). Significant removal of aqueous U(VI) was observed in NZVI-cement slurries and minimal adsorbed U was desorbed by a bicarbonate/carbonate (CARB) solution...
January 2019: Chemosphere
Paula López-Arce, Fernando Garrido, Javier García-Guinea, Andreas Voegelin, Jörg Göttlicher, Jose Miguel Nieto
Samples of an open-air pyrite roasting heap from the 19th century in the Riotinto mine area (SW Spain) and surrounding sediments and soil along a seasonal surface runoff channel were analyzed to study thallium (Tl) phase transformations during historical roasting of Tl-bearing arsenian pyrite, secondary weathering processes, Tl dispersion and current environmental pollution. Results from Electron Probe Microanalyses (EPMA) indicate an even distribution of Tl in pyrite grains of an ore sample (22 mg kg-1 total Tl), suggesting that Tl is incorporated in the pyrite structure rather than in discrete Tl-sulfide microparticles...
January 15, 2019: Science of the Total Environment
Mengtuan Ge, Dengjun Wang, Junwei Yang, Qiang Jin, Zongyuan Chen, Wangsuo Wu, Zhijun Guo
Remediating uranium contamination becomes a worldwide interest because of increasing uranium release from mining activities. Due to ubiquitous presence of pyrite and the application of iron-based technology, colloidal iron oxy-hydroxides such as akaganéite colloid (AKC) extensively exist in uranium polluted water at uranium tailing sites. In this context, we studied individual and co-transport of U(VI) and AKC in water-saturated sand columns at 50 mg/L AKC and environmentally relevant U(VI) concentrations (5...
October 5, 2018: Water Research
M García-Carmona, H García-Robles, C Turpín Torrano, E Fernández Ondoño, J Lorite Moreno, M Sierra Aragón, F J Martín Peinado
The present work assesses the residual pollution in the Guadiamar Green Corridor (SW, Spain) after a long-term aging process (18 years) since the accident of the Aznalcóllar pyrite mine. We have focused on the study of trace elements (Cu, Zn, Cd, As and Pb) in soils, their fractionation and the transference to the surrounding vegetation. The residual polluted areas are characterized by scattered plots with absence of vegetation, presenting high concentrations of trace elements, acidic pH and low organic carbon content...
February 10, 2019: Science of the Total Environment
Rebecca D McAuliffe, Daniel P Shoemaker
Non-stoichiometry is considered to be one of the main problems limiting iron pyrite, FeS2 , as a photovoltaic absorber material. Although some historical diffraction experiments have implied a large solubility range of FeS2-δ with δ up to 0.25, the current consensus based on calculated formation energies of intrinsic defects has lent support to line-compound behavior. Here it is shown that pyrite stoichiometry is relatively inflexible in both reductive conditions and in autogenous sulfur partial pressure, which produces samples with precise stoichiometry of FeS2 even at different Fe/S ratios...
October 1, 2018: Acta Crystallographica Section B, Structural Science, Crystal Engineering and Materials
Alexander J Krause, Benjamin J W Mills, Shuang Zhang, Noah J Planavsky, Timothy M Lenton, Simon W Poulton
Oxygen is essential for animal life, and while geochemical proxies have been instrumental in determining the broad evolutionary history of oxygen on Earth, much of our insight into Phanerozoic oxygen comes from biogeochemical modelling. The GEOCARBSULF model utilizes carbon and sulphur isotope records to produce the most detailed history of Phanerozoic atmospheric O2 currently available. However, its predictions for the Paleozoic disagree with geochemical proxies, and with non-isotope modelling. Here we show that GEOCARBSULF oversimplifies the geochemistry of sulphur isotope fractionation, returning unrealistic values for the O2 sourced from pyrite burial when oxygen is low...
October 4, 2018: Nature Communications
Kazumi Ozaki, Christopher T Reinhard, Eiichi Tajika
The possibility of low but nontrivial atmospheric oxygen (O2 ) levels during the mid-Proterozoic (between 1.8 and 0.8 billion years ago, Ga) has important ramifications for understanding Earth's O2 cycle, the evolution of complex life and evolving climate stability. However, the regulatory mechanisms and redox fluxes required to stabilize these O2 levels in the face of continued biological oxygen production remain uncertain. Here, we develop a biogeochemical model of the C-N-P-O2 -S cycles and use it to constrain global redox balance in the mid-Proterozoic ocean-atmosphere system...
October 3, 2018: Geobiology
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