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Electron energy loss spectra collected from fresh and corroded silver nanoparticles are compared with those from a number of reference materials, focusing on the M4,5 edge. Chemical shifts and changes in the energy loss near edge structure (ELNES) are described and found to be sufficient to distinguish metallic silver from chemically oxidised silver. The measurements, in conjunction with electron energy loss spectrum imaging, are used to assess the mechanisms for atmospheric corrosion of silver nanoparticles. We unambiguously assign the corrosion product under atmospheric conditions to be silver sulphide, but show the reaction process to be distinctly inhomogeneous, producing a variety of types of corroded particles.LAY DESCRIPTION: >Here, we use analytical electron microscopy to track the corrosion of silver nanoparticles and present chemical maps of the corrosion products. We show clear spectroscopic differences between metallic and corroded silver using the M4,5 electron energy loss spectral feature, which is not commonly studied. Our study shows that corrosion is due to interactions with sulphur in the atmosphere; and the corrosion is not uniform, but appears to develop from specific points on the surface of the nanoparticles. [ABSTRACT FROM AUTHOR]

Caulerpa is a genus of green macroalgae that lives in tropical and subtropical coastal waters. It is an intriguing organism because, despite having plant-like structures, it is one giant cell – which, next to multiple nuclei, chloroplasts, and mitochondria, also contains endo- and epiphytic bacteria. The role of these bacteria is unknown, but they might impact the growth and development of the host, adaptation to environmental parameters, and, hence, the ecological success of these algae. We hypothesised that increased sulphide concentrations would trigger a significant shift in the microbial community composition associated with C. prolifera rhizoids, favouring sulphide-oxidizing bacteria. To test this hypothesis, we conducted a mesocosm experiment incubating C. prolifera in sediments with different sulphide concentrations and analysed the algal photosynthesis, growth, and microbiome composition. While photosynthesis was not affected, the Caulerpa weight-based growth rate decreased linearly with increasing sulphide concentration. To analyse the microbiome, we extracted DNA and RNA from the fronds, rhizoids, and the accompanying sediments and performed 16S amplicon sequencing. The microbiome of the fronds was unaffected in both the DNA and RNA samples. However, an increase in sulphide concentration coincided with a decrease in the relative abundance of sulphate-reducing bacteria associated with Caulerpa rhizoids, particularly from the family Desulfocapsaceae. In the RNA samples, potential sulphide oxidisers of the rhizoid-associated members of the Beggiatoaceae were detected. Our results suggest that the rhizobiome of Caulerpa plays a significant role in its adaptation to sulphide-rich environments, offering new insights into the complex interactions within marine holobionts.

With the wastewater treatment project of a taurine production enterprise in Hubei as a case study, this paper analyzed the production process and wastewater quality characteristics of the enterprise, the targeted treatment process of “hydrolysis acidification+pre anoxic+aerobic biochemistry+post anoxic+secondary sedimentation” was adopted. When the average influent COD, ammonia nitrogen, and total nitrogen were 956.8, 50.6, 99.1 mg/L, respectively, the average effluent COD, ammonia nitrogen, and TN were 73.6, 1.6, 12.2 mg/L, respectively, with the average removal rates could reach 92.3%, 96.9%, and 87.7%, respectively. The effluent water quality was stable and meet the limits of water pollutants for newly built enterprises in the Chemical Synthesis Pharmaceutical Industry Water Pollutant Discharge Standard(GB 21904-2008). By adopting tapered aeration and fan frequency conversion control, energy consumption was significantly reduced, and the operating cost was 1.60 CNY/m3.

This study describes the biofilm formation by sulphate-reducing bacteria (SRB) on different materials, which has implications for the biomedical, pharmaceutical, food and chemical process industries. SRB was chosen as a model organism being an anaerobic bacterium. Biofilm formation on different materials and corrosion of titanium by SRB were monitored with time using confocal laser scanning microscopy and fluorescent FISH probes were used to authenticate the SRB strain. The thickness of the mono-culture SRB biofilm has ranged from 4 to 24 µm during thed 12–84 hr; however, the maximum biofilm thickness (24 µm) was recorded after 60 hr of growth. Planktonic growth of the SRB strain showed a log phase up to 48 hr and the sulphide production ranged from 2 to 14 mg l−1. For a comparative account, the SRB biofilm formation on copper was chosen as a positive control. Finally, the putative role of extracellular electron transfer by SRB in the biocorrosion process and the plausible mechanism of pitting corrosion of titanium is described in detail. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Exploration of Mercury will continue in the near future with ESA/JAXA's BepiColombo mission, which will increase the number and the type of datasets, and it will take advantage of the results from NASA's MESSENGER (MErcury Surface, Space ENviroment, GEochemistry and Ranging) mission. One of the main discoveries from MESSENGER was the finding of a relatively high abundance of volatiles, and in particular of sulphur, on the surface. This discovery correlates well with the morphological evidence of pyroclastic activity and with features attributable to degassing processes like the hollows. BepiColombo will return compositional results from different spectral ranges and instruments, and, in particular, among them the first results from the orbit of emissivity in the thermal infrared. Here, we investigate the results from the emissivity spectra of different samples between a binary mixture of a volcanic regolith-like for Mercury and oldhamite (CaS). The acquisitions are taken at different temperatures in order to highlight potential shifts due to both mineral variation and temperature dependence on these materials that potentially could be present in hollows. Different absorption features are present for the two endmembers, making it possible to distinguish the oldhamite with respect to the regolith bulk analogue. We show how, in the mixtures, the Christiansen feature is strongly driven by the oldhamite, whereas the Reststrahlen minima are mainly dominated by mafic composition. The spectral contrast is strongly reduced in the mixtures with respect to the endmembers. The variations of spectral features are strong enough to be measured via MERTIS, and the spectral variations are stronger in relation to the mineralogy with respect to temperature dependence. [ABSTRACT FROM AUTHOR]

In this article, the WC-10Ni coatings were fabricated by HVOF spray, then the ultrasonic cavitation erosion performances of the coatings in distilled water and 3.5 wt% NaCl solution with various Na2S concentrations (0, 20 and 200 ppm) were investigated. The results of the cumulative volume loss of the coating in different mediums showed that the coating exhibited enhanced cavitation erosion resistance with the increase of Na2S concentrations in medium. The reason for the improvement on the cavitation erosion performance was the growth of corrosion product films containing sulphide. In comparison with the coating after cavitation erosion in medium without Na2S, no large craters and deep grooves were observed on the eroded coating surface in medium with Na2S. The ultrasonic cavitation damage of the coating manifests as the spall of the metal binder phase (Ni) and exposure of the hard phase (WC).

The corrosion of copper in chloride‐ and sulphate‐containing solutions containing sulphide (ranging from 5 × 10−5 M to 10−3 M) was studied by electrochemical impedance spectroscopy and the structure and physical properties of the copper sulphide deposits (Cu2S) were analysed by scanning electron microscopy. At low [SH−], a porous and non‐protective deposit was formed, and the low corrosion rates were limited by sulphide transport, partially within the deposit and partially in the bulk of the solution. At higher [SH−], the corrosion rates were much higher and initially more rapid in chloride‐containing than in sulphate‐containing solutions, suggesting a direct role for chloride in the interfacial corrosion process. When the copper sulphide deposit thickened, the rate became limited by CuI transport within the more compact and more crystalline deposit formed. Changes in the morphology of the deposit suggest that chloride adsorption on the surfaces of the deposit inhibited the incorporation of Cu3S3 clusters, transported from the corroding copper surface, into the growing crystals. [ABSTRACT FROM AUTHOR]

In this study, the corrosion resistances of the HVOF sprayed Cr3C2–NiCr coating and nickel aluminium bronze (NAB) were tested in 3.5 wt.% NaCl solution with different Na2S concentrations, which included 0, 20, 100 and 200 ppm. Their corrosion behaviors were investigated by potentiodynamic polarization, cyclic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and constant potential polarization. The obtained data was used to analyze the effect of sulphide on corrosion mechanisms of the Cr3C2–NiCr coating. The potentiodynamic polarization outcome showed that the corrosion resistances of the Cr3C2–NiCr coating and NAB in the NaCl solution without sulphide were close to each other. However, the Cr3C2–NiCr coating exhibited more stable corrosion resistance in the NaCl solution containing sulphide than the NAB, which is attributed to the formation of passive film as confirmed by the cyclic polarization and EIS tests. The corrosion mechanism of the Cr3C2–NiCr coating and NAB showed different evolution with increasing sulphide in corrosion solution. Even if the NAB exhibited more stable current density than the Cr3C2–NiCr coating during constant potential polarization, the corrosion resistance of the NAB was inferior to that of the Cr3C2–NiCr coating.

The present study emphasizes the role of sulphide on ultrasonic cavitation erosion-corrosion (UCE-C) behaviors of HVOF-sprayed WC-Cr3C2-Ni coating in 3.5 wt% NaCl solution with different sulphide concentrations. The results indicated that the ultrasonic cavitation erosion (UCE) resistance of the coating decreased significantly with increasing sulphide concentration. The coating reacted with oxygen and anion those transferred by UCE, and the cavitation impact force led to the lack of support for tungsten carbide particles, which resulted in the reduction in the mass of the coating. There were two main factors those affected the UCE-C mechanism, in which the passivation film helped to reduce the mass loss of the coating, while the impact force caused by cavitation destroyed the passivation film, led to the accelerated anion diffusion and ultimately accelerated the mass loss of the coating. Mechanical erosion dominated the UCE-C of the coating in all tested solutions.

Acid sulphate soil and sulphide-bearing sediments cause various challenges in construction projects and land use planning, as well as harmful environmental effects. Fine-grained sulphide sediments were mainly formed in coastal areas during the Litorina Sea water phase at approximately 7000 BP in the capital region of Finland, but not all these sediments contain sulphide clay. In this study, environmental and material property variables related to the depositional conditions of sulphide clay were selected for statistical analyses to find their association with the occurrence of sulphide. The datasets consisted of sulphide investigations by the City of Espoo, the City of Helsinki, and the Geological Survey of Finland. Statistically significant associations were found in the study area between the occurrence of sulphide and enumerative variables (i.e., sediment organic content, total clay depth, topographic class in the Litorina Sea phase, and water depth) in the Litorina Sea phase. Locations where sulphide clay is especially likely to occur consist of organic-rich (≥ 2%) thick clay (≥ 15 m) deposits in a topographically narrow depression with deep Litorina water (≥ 30 m), or where there is a moderate depth clay (3–5 m) in a local depression with shallow Litorina water (10–20 m). The best individual predictor for sulphide clay occurrence in the study area was found to be the sediment organic content, and, together with sediment water content, these variables very accurately predicted the occurrence of sulphide clay. In addition, clay depth is a very good predictor and, together with the topographic class narrow depression and the Litorina water depth or current elevation, can be used to predict sulphide occurrence. [ABSTRACT FROM AUTHOR]

Thermophilic cyanobacteria thrive in sulphur-rich thermal springs. Mesophilic cyanobacteria thrive at temperatures between 28℃ and 37 ℃. This research was aimed at determining whether mesophilic cyanobacteria could thrive at high temperatures in the presence of sulphide and what could be the possible role of sulphide play in lessening thermal stress in mesophilic cyanobacterial organisms. The growth of the mesophilic cyanobacterium Nostoc ellipososporum was examined under thermal stress at its optimal growth temperature and in the presence and absence of sulphide. Under the same settings, the amount of enzymatic antioxidant was determined. Out of nine mesophilic cyanobacterial organisms tested, Nostoc ellipososporum was one thatgrew at 42°C, though at a slower rate than at 28°C. This organism's tolerance threshold for Sulphide was determined by growing it in a range of sodium sulphide concentrations (0.5 to 5 mM). The deleterious effect of thermal stress was eliminated by adding 2.5 mM sulphide to the cell cultures at 42℃. Enzymatic antioxidants (SOD, POD, and CAT) in the test organism were estimated under temperature stress and in the presence of sulphide. In the presence of sulphide, the levels of enzymatic antioxidants was evaluated. With an increase in antioxidants such as SOD, POD, and CAT the organism does exhibited growth with a slower rate at high temperature stress conditions. This is the first study to look into the role of sulphide in thermal stress relief by stimulating enzymatic reactions in the mesophilic cyanobacterium Nostoc ellipososporum. This revealed that reactive oxygen species were produced in response to heat stress but these antioxidants scavenged the free radicals that were generated. [ABSTRACT FROM AUTHOR]

It is important to develop active, stable, and cost-effective electrocatalysts for highly efficient overall water splitting. Metal organic frameworks were considered as efficient precursors for overall water splitting catalysts. In this paper, NC/Ni–Co3O4@Co1−xS with small size is obtained from ZIF-67. NC/Ni–Co3O4@Co1−xS materials exhibit superior overall water splitting properties, with a low overpotential of 170 mV for the hydrogen evolution reaction at 10 mA cm−2 and 210 mV for the oxygen evolution reaction at 10 mA cm−2 and long-term stability. Furthermore, the overall water splitting only requires 1.64 V to drive the current density of 10 mA cm−2, when the NC/ Ni–Co3O4@Co1−xS are used as both anode and cathode. NC/Ni–Co3O4@Co1−xS has excellent electrocatalytic activity due to its nanosheet structure, which greatly increases the electrochemically active surface area and the NC/Ni–Co3O4@Co1−xS has good electrical conductivity and abundant Co3+ sites, so the electrocatalytic activity is significantly enhanced. This study provides a new idea for the design and synthesis of novel composite electrocatalysts. [ABSTRACT FROM AUTHOR]

Exploration of Mercury will continue in the near future with ESA/JAXA’s BepiColombo mission, which will increase the number and the type of datasets, and it will take advantage of the results from NASA’s MESSENGER (MErcury Surface, Space ENviroment, GEochemistry and Ranging) mission. One of the main discoveries from MESSENGER was the finding of a relatively high abundance of volatiles, and in particular of sulphur, on the surface. This discovery correlates well with the morphological evidence of pyroclastic activity and with features attributable to degassing processes like the hollows. BepiColombo will return compositional results from different spectral ranges and instruments, and, in particular, among them the first results from the orbit of emissivity in the thermal infrared. Here, we investigate the results from the emissivity spectra of different samples between a binary mixture of a volcanic regolith-like for Mercury and oldhamite (CaS). The acquisitions are taken at different temperatures in order to highlight potential shifts due to both mineral variation and temperature dependence on these materials that potentially could be present in hollows. Different absorption features are present for the two endmembers, making it possible to distinguish the oldhamite with respect to the regolith bulk analogue. We show how, in the mixtures, the Christiansen feature is strongly driven by the oldhamite, whereas the Reststrahlen minima are mainly dominated by mafic composition. The spectral contrast is strongly reduced in the mixtures with respect to the endmembers. The variations of spectral features are strong enough to be measured via MERTIS, and the spectral variations are stronger in relation to the mineralogy with respect to temperature dependence.

Dilute magnetic semiconductor (DMS) is a trending research topic in material science for its requirements in spintronics technology in recent times. The present work reports the electrical and magnetic properties of different transition metal ions (Ti, V, Cr, Mn, Fe, Co, Ni and Zn)- doped silver copper sulphide. The dilute doping of transition metal ions at the copper site induces significant magnetic moments, which ordered ferromagnetically. The 3d orbital of the transition metal ions and the d orbital of Cu and Ag ions are the source of magnetisation. [ABSTRACT FROM AUTHOR]

The Abiete-Toko Gold District (ATGD), in the Nyong Complex, NW edge of the Congo Craton, is one of the numerous Cameroonian mining districts producing alluvial gold. Although numerous works were focused on the ATGD alluvial gold deposits, their primary source(s) remain(s) unknown. This study combines the chemistry of pyrite and chalcopyrite which were determined by inductively coupled plasma-mass spectrometry (LA-ICP-MS), the chemistry of alluvial gold grains determined by electron probe microanalysis (EPMA), and whole rock composition determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results provide the first evidence of gold in the rocks, and its genesis is subsequently discussed. Gold in the ATGD rocks is essentially invisible and lattice bound in pyrite and chalcopyrite, which intake up to 3.11 ppm and up to 32.6 ppm Au, respectively. The gold-bearing metatexites (garnet migmatite) and ultrabasites (serpentinised peridotites) are here therefore, interpreted as possible sources of the ATGD alluvial gold deposits and occurrences. In metatexite, pyrite and chalcopyrite occur within quartz biotite veins, while in ultrabasites pyrite and chalcopyrite are disseminated grains of millimetric sizes, and ovoid or cubic shapes. Gold mineralisation is shear-hosted and, shows evidence of hydrothermal alteration (sulphidation) induced by circulating magmatic and Co-rich (0.01–1.53 %) fluids. • In-rock gold ore at the Abiete-Toko Gold District shares similarities with orogenic-type gold deposits • pyrite and chalcopyrite in metatexite and ultrabasites are the main gold carriers in the Abiete-Toko Gold District rocks • Trace element scanning of pyrite and chalcopyrite reflect magmatic hydrothermal origin [ABSTRACT FROM AUTHOR]

Twenty silver minerals of the sulphide, arsenide, selenide, telluride, sulphosalt and chloride groups were found in 13 locations in the Variscan Karkonosze granitoid pluton. Previously only one of these minerals was known from this area. The findings include species characterized in publications as rare or exceptionally rare, e.g., muthmannite and tsnigriite. They occur in pegmatites and quartz veins; their parageneses are described. The studies include determination of chemical compositions, formulae calculations and recording of XRD patterns. Inclusion studies in paragenetic quartz indicate that they crystallized from epithermal fluids with a common but low component of CO2. The results suggest that the minerals formed from trace elements (Ag included) in the Karkonosze granitoid due to very local degrees of recrystallization of the host granitoid. [ABSTRACT FROM AUTHOR]

The presence of cobalt (Co) in sulphide deposits or sulphide-bearing iron oxide deposits in and around the Palaeoproterozoic Bergslagen ore province, south central Sweden, led to focused mining and extraction of this metal, particularly during the nineteenth century. Today, Co is considered a critical metal in the EU and among the more sought-after raw materials, not least due to its use in batteries for the rapidly increasing production of electric vehicles. Here we report new observations and data on Co concentrations in variably mineralised and not necessarily statistically representative samples from a suite of mainly skarn-hosted, at least locally, sulphide-dominated mineralisations from Bergslagen. While several localities that exhibit substantial Co concentrations represent deposits previously known to carry this metal (generally in a field/district or specifically in a mine), the majority are from mines or prospects in which the presence of Co have been hitherto unknown. Several of them share the enrichment of, e.g., Co and Cu, but the overall picture is one of more complex interrelations between the variable metal endowments in the known occurrences of Co in this province. While representing a modest dataset, our new observations complement previously available information on the occurrence of Co in Bergslagen and highlights both the need for, and potential of, new and more detailed studies on the distribution, mineralogy and origin of Co as well as other critical or near-critical metals in this and other ore provinces in Sweden. [ABSTRACT FROM AUTHOR]

Processed tailings in the Mixed tailings impoundment at the Macraes gold mine built up a sedimentary pile up to 100 m thick between 1990 and 2013. The tailings consist of sand-dominated fluvio-lacustrine sediments with fine (cm scale) bedding and have a mineralogical stratigraphy that reflects changing mine processes. Most of the tailings (>90%) consist of silicate minerals discarded from the flotation system throughout that time. The deepest tailings (1990–1993) have the lowest contents of sulphides as these were extracted and deposited separately. Between 1993 and 1999, tailings with up to 0.5 wt% sulphide sulphur (as pyrite and arsenopyrite) were deposited. Introduction of a pressure oxidation system in 1999 caused a substantial decrease in sulphide minerals and a parallel increase in ferric oxyhydroxide, ferric sulphate, and ferric arsenate compounds in which trace metals are dispersed. Some primary scheelite reacted during pressure oxidation conditions to form ferric tungstate compounds. Processing of auriferous sulphide concentrate from Reefton, western South Island, from 2007 introduced stibnite to the ore stream, and this was readily oxidised to form insoluble As-bearing ferric antimonate. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H 2 S) has traditionally been considered an environmental toxin for animal lineages; yet, it plays a signaling role in various processes at low concentrations. Mechanisms controlling H 2 S in animals, especially in sulfide-rich environments, are not fully understood. The main detoxification pathway involves the conversion of H 2 S into less harmful forms, through a mitochondrial oxidation pathway. The first step of this pathway oxidizes sulfide and reduces ubiquinone (UQ) through sulfide-quinone oxidoreductase (SQRD/SQOR). Because H 2 S inhibits cytochrome oxidase and hence UQ regeneration, this pathway becomes compromised at high H 2 S concentrations. The free-living nematode Caenorhabditis elegans feeds on bacteria and can face high sulfide concentrations in its natural environment. This organism has an alternative ETC that uses rhodoquinone (RQ) as the lipidic electron transporter and fumarate as the final electron acceptor. In this study, we demonstrate that RQ is essential for survival in sulfide. RQ-less animals (kynu-1 and coq-2e KO) cannot survive high H 2 S concentrations, while UQ-less animals (clk-1 and coq-2a KO) exhibit recovery, even when provided with a UQ-deficient diet. Our findings highlight that sqrd-1 uses both benzoquinones and that RQ-dependent ETC confers a key advantage (RQ regeneration) over UQ in sulfide-rich conditions. C. elegans also faces cyanide, another cytochrome oxidase inhibitor, whose detoxification leads to H 2 S production, via cysl-2. Our study reveals that RQ delays killing by the HCN-producing bacteria Pseudomonas aeruginosa PAO1. These results underscore the fundamental role that RQ-dependent ETC serves as a biochemical adaptation to H 2 S environments, and to pathogenic bacteria producing cyanide and H 2 S toxins., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

[Display omitted] • Selective copper hydrogel formation using terpyridine ligand L in dilute acidic medium. • Hydrogel is sensitive to S2− and I− ions. • Anion sensing study confirms the sensitivity of the copper complex towards S2− and I− ions with low LOD values. • DFT calculations were studied for non-covalent interactions and anion sensing study. 2,2′:6′,2″-Terpyridines (tpy) are well known for their ability to form a gel in the presence of transition metals. Due to the strong binding affinities towards transition metal ions aided by non-covalent interactions, tpy tends to form hydrogel with more than one metal ion. Interestingly, a simple chloro substituted 2,2′:6′,2″-terpyridine ligand L selectively forms a gel with only Cu(II) ion in a mild acidic medium. The hydrogel has a fibrous structure and is sensitive to S2− and I− anions, which is confirmed by both morphological analysis and rheological study. The copper complex was characterized using a variety of techniques, including HRMS, ESR, FTIR, elemental analysis, and DFT calculations. Further, DFT calculations were used to study the non-covalent interactions within the complex and to understand why the hydrogel responds to specific anions. The free energies of the CuI and CuS precipitate formation were calculated to get an idea of the feasibility of the process. Notably, UV–visible absorption spectroscopic study shows that the copper(II) complex CuCl 2 L selectively detected S2− and I− anions in aqueous acetonitrile with LOD of 2.63 and 2.08 μM, respectively. [ABSTRACT FROM AUTHOR]

The obtained CoNiV-X (X = P, S, Se) has been successfully prepared for HER in alkaline environment with high efficiency. [Display omitted] • Designed a CoNiV-X (X = P, S, Se) catalyst for alkaline environment HER. • The optimized CoNiV-P electrocatalyst exhibits a low overpotential (η 10 = 39 mV). • Research on DFT has unveiled the pivotal role of cobalt sites in the electron transfer process. • The electrocatalyst proposed by this study holds tremendous potential in hydrogen production. Exploring low-cost and high-efficient electrocatalysts to accelerate the sluggish kinetics of the hydrogen evolution reaction (HER) has attracted increasing research interest. The incorporation of nonmetallic elements (such as P, S, Se) into double hydroxides exhibits great potential to achieve high activity, increased stability, and reduced cost. In this study, a series of vanadium-doped cobalt–nickel sulfide/phosphide/selenide (CoNiV-X, X = P, S, Se) electrocatalysts were synthesized via a hydrothermal method and low-temperature phosphating, vulcanization, or selenization processes. These self-supported catalysts exhibited excellent HER performances and remarkable stability over a period of 96 h in the alkaline media (1.0 M KOH). Specifically, the optimized CoNiV-P electrocatalyst demonstrated a low overpotential (η 10 = 39 mV). The density functional theory studies revealed the crucial role of Co sites in the electron transfer process, contributing to the excellent performance of CoNiV-P electrocatalysts. This work proposes the electrocatalysts which may hold great potential for hydrogen production as a clean and sustainable alternative to polluting and finite fossil fuels. [ABSTRACT FROM AUTHOR]

The heterogenous mineralogy of ultramafic mine waste rocks make their carbonation rate hard to evaluate. This study investigated the effect of mineral composition on direct aqueous carbonation, through quantitative X-ray diffraction. The results show that magnesite was the main carbonated product, which was a stoichiometric conversion of forsterite. Diopside acted as a seed for quick crystallisation of magnesite. Lizardite could enhance the carbonation conversion, which reaches the optimum value when the weight ratio of lizardite to forsterite is 0.3–0.4. Sulphide in the reactant samples has a positive influence on carbonation. Brucite, magnetite and maghemite show little influence on carbonated products. [ABSTRACT FROM AUTHOR]

To strengthen students' concept of "Carbon neutrality" and the capability of the research and innovation, a comprehensive teaching experiment is designed to prepare transition metal sulfide-based photosensitizers, and the teaching content was carried out in the form of college students' innovative experiments. Through the design of multiple practical links, such as the preparation of near-infrared photosensitizer, characterization of the structure and photochemical properties, and evaluation catalysis performance, students can directly feel the charm of light energy. By exploring the mechanism of selective oxidation in the photocatalytic process, it can improve students' understanding of the theoretical knowledge of photocatalysis, stimulate their interest in scientific research and promote their innovation ability. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mine tailings resulting from orogenic gold processing commonly form arsenic (As)-enriched environments. A result of this is that they draw environmental attention in modern gold mining settings and significant effort in long-term rehabilitation. The Alexander River mine processing site in the Reefton area of Westland provides an opportunity to examine the natural rehabilitation of As-enriched tailings that have been left undisturbed for >70 years in a humid environment. These tailings comprise a ∼1 m thick package of finely laminated (mm-scale) sediments that were manually accumulated on a terrace downstream of the gold extraction plant. The tailings sediments are As-rich (up to 5000 mg/kg) due to relict arsenopyrite and As-bearing pyrite. Diagenetic Ca–Fe–arsenate (tentatively identified as yukonite) and As-bearing iron oxyhydroxide have formed during localised oxidation. There was sufficient calcite in the tailings to maintain circumneutral pH in the tailings despite sulphide oxidation. The historical tailing impoundment is now covered by grass, ferns and shrubs, with beech and rimu forest covering several metres at the margins. Leaf analyses indicate that the vegetation is absorbing only minor As. Therefore, the tailings substrate has not halted natural vegetation re-colonisation of this As-rich historical site. [ABSTRACT FROM AUTHOR]

Wild rice (WR; Zizania palustris L.) growth response to sediment obtained from Rat River Bay (RRB; control site), Cleaver Lake (CL; legacy zinc-copper mine influenced), and Unnamed Lake (UL; active gold mine influenced) was evaluated by two bioassay systems: (1) a mesocosm-scale bioassay and (2) an accelerated-growth microcosm-scale bioassay. Following an entire growing season of 7 weeks, WR developed to near reproductive maturity, with similar observations using both systems. WR height (HT), dry weight biomass (DWB), and seed production (SP) were statistically higher in RRB than both CL and UL sediment-grown plants. Significant differences were not identified between mesocosm:microcosm ratios for DWB or SP; HT ratios were significant. Wild rice HT, DWB, and SP were statistically lower for CL and UL sediment-grown plants; however, visual differences in growth between sediments were documented mid-season. By the end of the season, ammonia–nitrogen (N) was below detection in CL and UL sediment and decreased by 93% in RRB sediment. Responses of WR to these sediment exposures appeared to be more influenced by ammonia-N concentration than other sediment constituents. Based on data obtained during this study, the microcosm-scale bioassay accurately represented the mesocosm-scale bioassay in terms of WR DWB and SP, both of which were visually recognized. Use of this microcosm-scale bioassay to obtain accurate representations of WR responses to site-specific sediment, or water, exposures can save industry and critical water resource managers time, money, and overall resources. [ABSTRACT FROM AUTHOR]

The article presents the possibility of recovering nickel from waste produced as a result of wastewater neutralization during the electrochemical surface treatment of metals. Leaching the sludge with concentrated hydrochloric acid enabled the metals contained in the sludge from precipitate to the solution with the efficiency of 74.4% (Se) to 100% (Zn). The content of elements was determined using the ICP-OES method. The next step was the precipitation of metals from the obtained solution using various reagents. The precipitating reagents used were 0.5 M sodium hydroxide solution, 0.5 M sodium sulphide solution and 1% dimethylglyoxime solution. Selective precipitation made it possible to obtain nickel concentrates with the content of nickel ranging from 15.3 to 98.2% for the first two methods, whereas in the case of the third method based on a dimethylglyoxime solution, the obtained nickel concentrate purity was 94.3%. The process of leaching nickel-dimethylglyoxime complex (Ni-DMG) with sulphuric acid and crystallization enabled obtaining 99.4% purity nickel sulphate, which can be reused in the nickel plating of selected metals. The research shows that waste generated in the process of neutralization of wastewater from electroplating plants is a potentially important source of recycled nickel concentrates. [ABSTRACT FROM AUTHOR]

This review presents last decade and some past especially relevant studies in the field of (+)-3-carene synthetic transformations. This paper discusses exclusively the transformations of (+)-3-carene, proceeding with the retention of the native bicyclic carbon skeleton. The data concerning the features of epoxidation and oxidation reactions of (+)-3-carene, the synthesis of sulphur- and selenium-containing derivatives and their use in asymmetric synthesis are given. It also describes methods for producing amino derivatives of (+)-3-carene, substituted heterocycles based on it, reactions for the preparation of aziridines, azido-alcohols and azidoamines, as well as chiral phosphites as bidentate ligands.

The nature of the chemical environment in oil and gas fluids such as produced water (PW) and soured oil or low‐oxygen environments plays a vital role in microbiologically influenced corrosion (MIC). H2S and/or other forms of sulphur species in soured oils and PW are key factors in the corrosion and growth of microorganisms. To mitigate reservoir souring and subsequent corrosion, nitrate is injected to displace sulphate‐reducing bacteria with nitrate reducers. However, nitrates and the associated nitrogen species (eg, nitrite) impact the chemistry and microbial activity, and hence the corrosion potential in the system. This study investigates the PW chemical environment in light of sulphide and nitrite chemistry, and provides information towards understanding the chemical transformations and microbial relationships. The sulphide‐nitrite environment was studied as a function of temperature, pressure, nitrite level, oxygen‐using equilibrium, and kinetic model approaches. Equilibrium simulation predicted the formation of FeS, FeO(OH), and Fe2O3 as the key corrosion products, the amount of which varied depending on the chemistry and operating conditions. In experiments where nitrite was very low or absent, S0 was favoured over SO42− as the inlet H2S concentration increased and FeS dominated with an increase in temperature. In the presence of nitrite, Fe2O3 was formed instead of FeO(OH) at temperatures above 50°C. The trend of the kinetic simulation of the sulphide‐oxygen reaction in seawater was in good agreement with the wet‐lab experiment in PW. The models can serve as tools to better understand and describe the chemical environment in PW systems. [ABSTRACT FROM AUTHOR]

Exploration of precious metals in contact with sulphide ores has gained popularity with the exhaustion of the minerals in high grade ore regions. The processing of the sulphide ores via convectional metallurgical practices come with challenges in stages demanding high settling rates of solid suspensions, and hence the research on the production of novel ionic polyacrylamide to facilitate higher settling rates of the sulphide solid suspensions during flocculation and disposal of tailings. This involves the synthesis of aluminium hydroxide colloids with novel ionic properties through the dissolutionprecipitation route of Al(OH) microagglomerates. Subsequent polymerization of acrylamide monomer was then done in 3 the presence of the colloidal suspension to produce novel ionic Al-PAM. The molecular weight of the synthesized polymer 6-1 was determined using intrinsic viscosity, with a peak of 16.19 ×10 gmol obtained at a concentration of 30%. The Degree - of Anionicity (DA) was found to be 56.86% determined using peak values of the -COO and -CO groups from the Fourier Transform Infrared Spectrum (FTIR). Samples of sulphide tailings were then used to evaluate the suitability of the novel Al-PAM in increasing the settling rates during flocculation. [ABSTRACT FROM AUTHOR]

Small lead sulphide films (PbS) are applied to the parts of the glass slide using a chemical bath processor (CBD) at room temperature for 60 minutes. The visual characteristics of the thin films were measured with a spectrophotometer and some solid state structures were determined by comparing the absorption data at a distance of 300-900 nm using software. The software used three types of simulation. SEM micrograph, Band gap (Eg), Absorbance (A), and Raman shift were tested as a function of wavelength and photonenergy. Further analysis has shown that the band gap of PbS films increases as Lead concentration increases. [ABSTRACT FROM AUTHOR]

• Synthesis of mercury complex HgCl 2 L of terpyridine ligand l. • HgCl 2 L characterised with 1HNMR , HRMS, IR, and SC-XRD. • In-situ prepared HgCl 2 L selective detects S2− anion in aqueous CH 3 CN medium. • The LOD value for sulphide detection is 1.01 μM. A novel mercury complex HgCl 2 L of 4′-(4-N,N´-dimethylaminophenyl)-2,2´:6′,2´´-terpyridine ligand L has been synthesized and characterised using 1H NMR, HRMS, FT-IR spectroscopy and CHN analysis. The crystal structure of HgCl 2 L exhibits distorted square pyramidal geometry. Further, the complex HgCl 2 L is utilised for selectively detecting sulphide (S2−) anion with other competitive anions in aqueous acetonitrile (4:1 v/v) medium. UV–visible absorption spectral studies and colorimetric approach confirmed the selectivity of the complex towards S2- and the limit of detection has been determined to be 1.01 μM. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • An exceptional sulfide zonation in gold orebodies. • Gold enrichment by two routes: recrystallization and sequestration. • The pyrrhotite-arsenopyrite domains are potentially targets for more gold resources. The Middle–Lower Yangtze River Valley metallogenetic belt (MLYRB) is a large and economically valuable porphyry–skarn Cu–Au ore belt in China with a total reserve of >600 tonnes of gold. Orebodies in the MLYRB are commonly stratabound and extend for several tens of metres in length and locally for more than 1000 m. However, the origin of the stratabound orebodies is uncertain, with proposals including a magmatic or sedimentary genesis, and the specific processes by which these gold deposits were formed are also unclear. Here we report a study of the representative stratabound Jiaochong Au deposit in the Tongling ore district, where stratified gold orebodies are hosted at the Triassic -Permian strata boundary. A detailed field survey, petrologic observations, in situ sulfur isotopic analysis, and major and trace element compositional analysis of gold and sulfide grains were carried out to determine how the gold was enriched. Field survey shows that precipitated sulphides exhibit obvious mineral and textural zonation from wall-rock to orebody centres as follows: Zone 1, colloform pyrite (Py 1) ± sphalerite ± chalcopyrite → Zone 2, euhedral pyrite (Py 2) ± pyrrhotite + arsenopyrite ± colloform pyrite (Py 1) → Zone 3, pyrrhotite + arsenopyrite. From zone 1 to zone 3, the sulphides were progressively phase-transformed, with the earlier Py 1 being gradually consumed and converted into Py 2 , which finally became pyrrhotite. The gold deposition occurs in Zones 2 and 3 and forms two generations of gold grains, one group being completely enclosed within euhedral Py 2 with low As contents (<0.1 wt%) and another group infilling fractures between arsenopyrite and pyrrhotite or occurring as inclusions within arsenopyrite with high As contents (0.4 to 1.4 wt%). The comparable S-isotope compositions of the ore sulfides to those of Mesozoic intermediate-felsic intrusions and the veining characteristics of colloform pyrite in the Tongling ore district suggest that Mesozoic magmatic-hydrothermal fluids, rather than Carboniferous sedimentary rocks as usually thought, provided the principal ore-forming materials. The gold precipitation in this study followed two continuous processes: recrystallisation and arsenopyrite sequestration; in the first process, Au is remobilised from the pyrite structure at higher temperatures up to recrystallisation of fine-grained, colloform morphologies into euhedral crystals and formation of Au-bearing metallic particles (Au 1); with the ongoing recrystallisation more As is released and accumulated into the equilibrated fluids, forming As-rich pyrite or arsenopyrite and a second period of gold deposition (Au 2). The continuous sulphide zonation texture and phase transformation, similar to Jiaochong, have been observed in other gold deposits in the MLYRB, and our gold enrichment processes may also give an explanation for the formation of these stratabound gold deposits. [ABSTRACT FROM AUTHOR]

The data presented in this article are related to the measurements in the contribution titled: ‘Tarnished silver-copper surfaces reduction using remote helium plasma at atmospheric pressure studied by means of high-resolution synchrotron x-ray photoelectron microscopy’ published in Corrosion Science. X-ray photoelectron spectra were collected from pure silver, sterling silver (92.5 w% Ag and 7.5 w% Cu) alloy and pure copper. These metals were artificially sulphidised. A remote helium plasma at atmospheric pressure was applied on the metallic and sulphidised state. Then the top layer of the 4 surface states were analysed at the NanoESCA beamline (Electron Spectroscopy for Chemical Analysis at the Nanoscale) at Elettra Sincrotrone Trieste. The instrument installed as an end station at the NanoESCA beamline of the Elettra storage ring combines an electrostatic Photo Electron Emission Microscope (PEEM) with a double-hemispherical (‘IDEA’) analyser, allowing the collection of photoemission electron microscopy (PEEM) images, X-ray photo electron-energy-filtered images and XPS spectra. The NanoESCA beamline provides electromagnetic radiation with variable polarization (linear, circular) and energies up to 1000 eV. Information for Cu3p, Cl2p, S2p, C1s and Ag3d were obtained by collecting spectra at 450 eV. The goal of the analyses was to determine how the plasma treatment changed the top layer of the metallic and sulphidised surface of pure silver, sterling silver and pure copper. This contribution focuses on the calibration of the collected XPS spectra, as well as the impact of the plasma treatment on the surface states.

The Snowy River processing site was used to extract gold for the large historic Blackwater mine, Westland, between 1906 and 1938, and then abandoned. The site is now one of the best-preserved historic gold-processing localities, and access has been enhanced for visitors. The site has some high arsenic (As) concentrations on the surface, with some spots exceeding 40 wt% As. A variety of As-bearing minerals occurs along the former processing stream, from primary sulphides (arsenopyrite, pyrite) at the upstream end to arsenolite (As2O3) and scorodite (FeAsO4.2H2O) formed by the roasting of ore materials at the downstream end. Weathering over the past century of sulphide residues and some of the arsenolite has yielded more scorodite and some Ca arsenates. Minor authigenic As sulphide precipitates have formed on rotting wood. Arsenolite is principally distributed near to the roaster site, and this is the most soluble and potentially toxic mineral on site. Despite the locally abundant arsenolite, only minor As is mobilised into nearby waters. [ABSTRACT FROM AUTHOR]

Posiva Oy is preparing to submit an operating licence application for a spent nuclear fuel geologic repository located at Olkiluoto, Finland. The construction licence for the underground disposal facility and encapsulation plant was granted in 2015 and construction of the disposal facility began in December 2016. Safe disposal is achieved by the KBS‐3 concept, developed in collaboration with Posiva's Swedish counterpart, the Swedish Nuclear Fuel and Waste Management Co, (SKB). The KBS‐3 concept consists of disposal canisters (a cast iron insert and a copper overpack), surrounded by swelling bentonite and disposed in crystalline bedrock. The copper overpack ensures containment of radioactive materials and its performance against corrosion is a key driver for the design of the engineered barrier system and the repository overall. This paper describes the current status of the Posiva programme, recent learnings from the construction of the repository, and the implications for the long‐term performance of the canister. [ABSTRACT FROM AUTHOR]

Sulphur is of particular importance in the subduction zone system, as it is thought to be intimately related to the arc redox state and metallogenesis above the slab. Knowing the sulphur isotope compositions of the subducted slab, and identifying the δ34S variations between the pre-subduction oceanic lithosphere and its high-pressure (HP) equivalents is of great importance for understanding the sulphur behaviour in subduction zones and the long-term sulphur recycling of the Earth. In this study, we undertook secondary ion mass spectroscopy (SIMS) in-situ δ34S analyses of sulphides from metasediments, mafic blueschists/eclogites, and ultramafic slab serpentinites from the Southwestern Tianshan HP–UHP metamorphic belt, which represents one of the deepest fossil subduction zones on Earth. By integrating the in-situ δ34S compositions of sulphides studied here and those reported from worldwide HP–UHP metamorphic terranes, we found that prograde to peak metamorphic sulphides of metasediments, metabasites/metagabbros, and slab HP serpentinites have δ34S values ranging from –33 to –6‰, –4 to +4‰, and +2 to +18‰, respectively. However, retrograde metasomatism of HP rocks during exhumation may alter the δ34S compositions of sulphides. The integrated dataset proposes that sulphides in subducting slab sequences retain their protolith's δ34S signatures during HP metamorphism. The δ34S inheritance indicates that no large isotope fractionation is expected to occur in subduction zones. It further suggests that evaluations of slab subduction effects on the δ34S signature of arc magmatism and the deep mantle should consider pre-subduction processes such as ridge geodynamic setting and hydrothermal alteration. [ABSTRACT FROM AUTHOR]

A temporal framework for mineral deposits is essential when addressing the history of their formation and conceptualizing genetic models of their origin. This knowledge is critical to understand how crust-forming processes are related to metal accumulations at specific time and conditions of Earth evolution. To this end, high-precision absolute geochronology utilising the rhenium-osmium (Re-Os) radiometric system in specific sulphide minerals is becoming a method of choice. Here, we present a procedure to obtain mineral separates of individual sulphide species that may coexist within specific mineralized horizons in ore deposits. This protocol is based on preliminary petrographic and paragenetic investigations of sulphide and gangue minerals using reflected and transmitted light microscopy. Our approach emphasizes the key role of a stepwise use of a Frantz isodynamic separator to produce mineral separates of individual sulphide species that are subsequently processed for Re-Os and sulphur isotope geochemistry. • Detailed method and its graphical illustration modified from an original procedure introduced by Saintilan et al. (2017, 2018). • Quality control and validation of monophasic mineral separates made by microscopic investigations and qualitative analysis of aliquots embedded in epoxy mounts. • The present method, which contributed to the successful results presented in the co-publication by Saintilan et al. (2020), demonstrates why other studies reporting Re-Os isotope data for mixtures of sulphide minerals should be considered with caution.

Pyrite is the most common mineral in polymetallic sulphides ores. In order to apply the combustion group theory to the pyrometallurgical processes that occur in the reaction shaft, it is necessary to know the kinetic processes that happen in pyrite. In this study, thermogravimetric analysis was carried out under oxidative atmospheric conditions with 100% O2 and a heating ramp of 5, 10, 15 and 20 °C min−1. The material used was pyrite with a grain size of 63–125 μm. From the thermogravimetric data, we got the kinetic parameters of the oxidative reactions of pyrite. The different kinetic methods used in this study have been E1641-16 ASTM, Ozawa–Flynn–Wall, Kissinger–Akahira–Sunose and Friedman. These methods were used for obtaining the kinetic parameters through regression analysis, sum of squares, mean residuals between experimental and calculated values and Student coefficient (95%) and to determine which kinetic method is the most suitable to describe the kinetics of pyrite oxidation. [ABSTRACT FROM AUTHOR]

Sulphide is one of the known environmental stressors, which potentially binds to cytochrome C oxidase (COX), a key enzyme in the electron transport chain, thereby blocking oxygen transport and ATP production. To ascertain the toxic effects of sulphide on Pacific white shrimp, Penaeus vannamei, two distinct exposure experiments were carried out with varying concentration of sulphide (0–1 mg/L), dissolved oxygen (normoxia and hypoxia) and pH values (8.2, 6 and 5). The activity of enzymes viz COX, superoxide dismutase (SOD), phenoloxidase and lactate accumulation was investigated. Outer membrane integrity and COX monomer separation were also done with the isolated crude mitochondrial preparations. Results indicated a significant reduction (p ≤.05) in COX enzyme activity in sulphide exposed treatments when compared to control. The reduction was more intense when pH levels were reduced under hypoxia condition. Lactate accumulation as a result of anaerobic metabolism was found to be higher in hypoxic treatments. No significant difference (p ≥.05) was observed in superoxide dismutase activity between the treatments, whereas phenoloxidase activity significantly decreased at higher concentration sulphide. Separation of mitochondrial proteins resulted in the identification of ~205 kDa of COX monomer, and significant damage was found in outer membrane integrity under hypoxia and pH treatments. From this study, it is evident that at a given concentration, sulphide is toxic to P. vannamei, and in association with hypoxia and low pH, they further intensify sulphide toxicity. Our results indicated that sulphide toxicity should not be considered as a single factor, rather it should be a considered as combination of factors. [ABSTRACT FROM AUTHOR]

Modulation of the ageing process by dietary restriction (DR) across multiple taxa is well established. While the exact mechanism through which DR acts remains elusive, the gasotransmitter hydrogen sulphide (H2S) may play an important role. We employed a comparative-type approach using females from three ILSXISS recombinant inbred mouse strains previously reported to show differential lifespan responses following 40% DR. Following long-term (10 months) 40% DR, strain TejJ89—reported to show lifespan extension under DR—exhibited elevated hepatic H2S production relative to its strain-specific ad libitum (AL) control. Strain TejJ48 (no reported lifespan effect following 40% DR) exhibited significantly reduced hepatic H2S production, while H2S production was unaffected by DR in strain TejJ114 (shortened lifespan reported following 40% DR). These differences in H2S production were reflected in highly divergent gene and protein expression profiles of the major H2S production and disposal enzymes across strains. Increased hepatic H2S production in TejJ89 mice was associated with elevation of the mitochondrial H2S-producing enzyme 3-mercaptopyruvate sulfurtransferase (MPST). Our findings further support the potential role of H2S in DR-induced longevity and indicate the presence of genotypic-specificity in the production and disposal of hepatic H2S in response to 40% DR in mice. [ABSTRACT FROM AUTHOR]