Academic literature on the topic 'Sulphide media'
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Journal articles on the topic "Sulphide media":
1
MENDES-FERREIRA, A., A. MENDES-FAIA, and C. LEÃO. "Survey of Hydrogen Sulphide Production by Wine Yeasts." Journal of Food Protection 65, no. 6 (June 1, 2002): 1033–37. http://dx.doi.org/10.4315/0362-028x-65.6.1033.
Abstract:
Twenty-one strains of commercial wine yeasts and 17 non-Saccharomyces species of different provenance were surveyed for their ability to produce hydrogen sulphide in synthetic grape juice medium indicator agar with different nitrogen sources, as well as in natural grape juice. Bacto Biggy agar, a commercially available bismuth-containing agar, was used to compare our results with others previously reported in the literature. Under identical physiological conditions, the strains used in this study displayed similar growth patterns but varied in colony color intensity in all media, suggesting significant differences in sulphite reductase activity. Sulphite reductase activity was absent for only one strain of Saccharomyces cerevisiae. All other strains produced an off-odor to different extents, depending significantly (P <0.05) on medium composition. Within the same species of some non-Saccharomyces yeasts, strain variation existed as it did for Saccharomyces. In natural musts, strains fell into three major groups: (i) nonproducers, (ii) must-composition-dependent producers, and (iii) invariable producers. In synthetic media, the formation of sulphide by strains of S. cerevisiae results from the reduction of sulphate. Therefore, this rapid screening methodology promises to be a very useful tool for winemakers for determining the risk of hydrogen sulphide formation by a given yeast strain in a specific grape juice.
2
Takahashi, Junichi, Nobuyuki Johchi, and Hiroshi Fujita. "Inhibitory effects of sulphur compounds, copper and tungsten on nitrate reduction by mixed rumen micro-organisms." British Journal of Nutrition 61, no. 3 (May 1989): 741–48. http://dx.doi.org/10.1079/bjn19890159.
Abstract:
1. The inhibitory effects of inorganic and organic sulphur-containing compounds, copper and tungsten on nitrate reduction by mixed rumen micro-organisms were investigated in two in vitro studies.2. Coarsely strained rumen fluid from nitrate-adapted (Expt 1) or non-adapted (Expt 2) Suffolk Down wethers maintained on lucerne (Medicago sativa) cubes was used as an inoculum. In Expt 1, anaerobic incubation was carried out for 24 h for each medium supplemented with 10 mM-sodium nitrate and the following chemicals: 0, 1, 2, 3, 5, 8 and 10 mM-sodium sulphide, 1 and 10 mM-sodium sulphite, 1 and 10 mM-sodium sulphate, 1 and 10 mM-L-cysteine, 1 and 10 mM-DL-methionine, 1 mM-sodium tungstate and I mM-copper sulphate. In Expt 2, 1 and 10 mM-Na2S, 1 and 10 mM-L-cysteine, 1 mM-Na2WO4, and 1 mM-CuSO4were added to incubation media to test for chemical inhibition of microbial reduction of nitrate.3. In Expt 1, the amount of nitrite formed decreased with increasing concentration of sulphide-S added. The additions of L-cysteine, W and Cu suppressed nitrite formation in media from both nitrate-adapted and non-adapted sheep.4. In contrast to the effects of sulphide, L-cysteine and W counteracted, to some degree, nitrate-induced reduction of volatile fatty acid (VFA) production. Addition of Cu to the media resulted in a further depression of VFA production.
3
Jeroschewski, Paul, Karen Haase, Andreas Trommer, and Peter Gr�ndler. "Galvanic sensor for the determination of hydrogen sulphide/sulphide in aqueous media." Fresenius' Journal of Analytical Chemistry 346, no. 10-11 (1993): 930–33. http://dx.doi.org/10.1007/bf00322753.
4
Massacci, P., M. Recinella, and L. Piga. "Factorial experiments for selective leaching of zinc sulphide in ferric sulphate media." International Journal of Mineral Processing 53, no. 4 (May 1998): 213–24. http://dx.doi.org/10.1016/s0301-7516(98)00002-7.
5
Vukovic, Milovan, Nada Strbac, Miroslav Sokic, Vesna Grekulovic, and Vladimir Cvetkovski. "Bioleaching of pollymetallic sulphide concentrate using thermophilic bacteria." Chemical Industry 68, no. 5 (2014): 575–83. http://dx.doi.org/10.2298/hemind130905087v.
Abstract:
An extreme thermophilic, iron-sulphur oxidising bacterial culture was isolated and adapted to tolerate high metal and solids concentrations at 70?C. Following isolation and adaptation, the culture was used in a batch bioleach test employing a 5-l glass standard magnetic agitated and aerated reactor, for the bioleaching of a copper-lead-zinc collective concentrate. The culture exhibited stable leach performance over the period of leach operation and overall copper and zinc extractions higher than 97%. Lead sulphide is transformed into lead sulphate remaining in the bioleach residue due to the low solubility in sulphate media. Brine leaching of bioleach residue yields 95% lead extraction.
6
Wilton, Derek H. C., Gary M. Thompson, and Dawn Evans-Lamswood. "MLA-SEM Characterization of Sulphide Weathering, Erosion, and Transport at the Voisey’s Bay Orthomagmatic Ni-Cu-Co Sulphide Mineralization, Labrador, Canada." Minerals 11, no. 11 (November 4, 2021): 1224. http://dx.doi.org/10.3390/min11111224.
Abstract:
The Voisey’s Bay nickel-copper-cobalt (Ni-Cu-Co) sulphide deposits constitute a significant resource of orthomagmatic mineralization. The deposits are not exposed at the surface except for in a small ferruginous gossan (Discovery Hill). The subsequent geophysical surveys and diamond drilling led to the discovery of the Ovoid ore body, buried beneath 20 m of till, and other deeper deposits in the bedrock. This study was initiated to characterize the sulphide mineralogy of these deposits through various stages of weathering, erosion, and transport. Because the samples ranged from bedrock through to a variety of surficial sediment types, the automated SEM-based identification provided by the MLA-SEM system was the ideal technique to quantitatively evaluate mineral distributions in the different media. The derived MLA-SEM data indicate that, aside from the Discovery Hill gossan, the surface sulphide mineralization at Voisey’s Bay was weathered in a pre-glaciation regolith at the Mini-Ovoid deposit and, on the surface of the Ovoid deposit, the massive sulphide was unoxidized due to a thin calcite-cemented clay cover. Pentlandite is very preferentially oxidized compared to other sulphides in the Voisey’s Bay ore, to depths of up to 10 m in bedrock. Conversely, within the coarse reject samples of crushed drill cores stored in sealed plastic bags, pyrrhotite was altered, whereas pentlandite and chalcopyrite are stable, presumably due to anaerobic reactions. The MLA-SEM detected trace amounts of minute sulphide grains in surficial sediments, but their contents abruptly decreased with distance from the sulphide mineralization. Microtextures such as troilite and pentlandite exsolution or twinning in pyrrhotite, however, could be observed in the fine sulphide grains from till, suggesting a derivation from orthomagmatic sulphide material, such as the Voisey’s Bay mineralization.
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Dutrizac, J. E. "The leaching of sulphide minerals in chloride media." Hydrometallurgy 29, no. 1-3 (June 1992): 1–45. http://dx.doi.org/10.1016/0304-386x(92)90004-j.
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Tan, J., and R. K. Hailstone. "Gold–sulphide versus sulphide centres on (111) AgBr surfaces: characterization and mechanism." Imaging Science Journal 52, no. 4 (December 2004): 202–11. http://dx.doi.org/10.1179/136821904x6442.
9
Miyamoto, Yasushi, and Chitose Iwanaga. "Effects of sulphide on anoxia-driven mortality and anaerobic metabolism in the ark shell Anadara kagoshimensis." Journal of the Marine Biological Association of the United Kingdom 97, no. 2 (March 21, 2016): 329–36. http://dx.doi.org/10.1017/s0025315416000412.
Abstract:
Reduction in survival under hypoxic conditions in the presence of sulphide has been repeatedly demonstrated in various benthic invertebrates. However, the reason for this reduction has not yet been clearly elucidated. In this study, the effects of sulphide accumulation on anoxic survival and anaerobic metabolism were investigated in the ark shell Anadara kagoshimensis. Ark shells from western Japan were experimentally exposed to 3 sulphide-accumulation levels under sustained anoxic conditions: accumulated H2S treatment (static incubation), decreased H2S treatment (semi-static incubation with daily replacement of incubation media), and inhibited H2S treatment (static incubation with the addition of antibiotics). Moreover, the effect of antibiotics on anoxic survival was examined under sulphide exposure. The decreased H2S and inhibited H2S treatments resulted in 1.5- and 3-fold increase in the anoxic survival time, respectively, when compared with the accumulated H2S treatment. Under anoxic sulphide exposure, the antibiotics addition did not affect survival time, suggesting the shorter survival time in the accumulated H2S incubation was probably due to sulphide toxicity. Glycogen consumption and propionate accumulation, which indicate activation of anaerobic metabolism, were observed in both accumulated and inhibited H2S treatments. However, glycogen consumption was significantly higher in the accumulated H2S treatment after a significant sulphide accumulation was detected in the incubation media. In addition, survival in the accumulated H2S treatment decreased rapidly, whereas no significant mortality was observed in the inhibited H2S throughout the experiment. These results likely suggest that the accelerated anoxic-driven mortality in sulphide-rich environments was partly due to the faster breakdown of glycogen.
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Camarillo, Mary Kay, William T. Stringfellow, Jeremy S. Hanlon, and Elizabeth Basha. "Performance of sanitary sewer collection system odour control devices operating in diverse conditions." Water Science and Technology 68, no. 12 (October 24, 2013): 2527–33. http://dx.doi.org/10.2166/wst.2013.492.
Abstract:
Controlling odours from sanitary sewer systems is challenging as a result of the expansive nature of these systems. Addition of oxidizing chemicals is often practiced as a mitigation strategy. One alternative is to remove odorous compounds in the gases vented from manholes using adsorptive media. In this study, odour control devices located at manholes were observed to determine the ability of these systems to reduce hydrogen sulphide from vented gases. The odour control devices incorporated pressure regulation to control gas flow out of manhole covers and adsorptive media to remove hydrogen sulphide in the vented gases prior to release. Pressure regulation was accomplished using a variable volume bladder and two pressure relief valves that permitted gas flow when pressures exceeded 1.3 to 2.5 cm water column. The reduction in gas flow vented from manholes was intended to extend the service life of the adsorptive media, as compared with odour control devices that do not incorporate pressure modulation. Devices were deployed at four locations and three adsorptive media were tested. Although measured collection system hydrogen sulphide concentrations varied from zero to over 1,000 ppm, the removal rates observed using odour control devices were typically above 90%. The lower removal rates observed at one of the sites (50.5 ± 36.1%) appeared related to high gas flow rates being emitted at this location. Activated carbon was used in most of the tests, although use of iron media resulted in the highest removal observed: 97.8 ± 3.6%. The expected service life of the adsorptive media contained within the odour control devices is a function of site-specific hydrogen sulphide concentrations and gas flow rates. The units used in this study were in service for more than 8 to 12 months prior to requiring media replacement.
Dissertations / Theses on the topic "Sulphide media":
1
Towey, Thomas. "Quantum-sized cadmium sulphide colloids prepared in microemulsion media." Thesis, University of East Anglia, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280029.
2
Warner, Terence Edwin. "An electrochemical study of the oxidative dissolution of synthetic nickel-iron sulphide minerals in aqueous media." Thesis, University of Leeds, 1988. http://etheses.whiterose.ac.uk/1075/.
Abstract:
Pentlandite (Fe4.5Ni4.5S8) and violarite (FeNi2S4) were synthesized by dry in vacuo techniques. The products were analysed by reflected light microscopy, powder X-ray diffraction and electron microprobe analysis. The synthetic pentlandite was found to have an average stoichiometry of Fe4.35Ni4.65S8. A partial phase segregation of pentlandite into heazlewoodite and pyrrhotite was observed. The synthetic violarite grains showed a zonal separation into a Fe1.2Ni1.8S4 core, and a Fe0.5Ni2.5S4 rim. Trace amounts of pyrite and millerite were also detected. From a critical review of the thermodynamic data in the literature, several Eh-pH diagrams were constructed for the Fe-Ni-S aqueous system. These were compared with mineralogical evidence obtained from naturally occuring mineral assemblages. A study of the oxidative dissolution of pentlandite by electrochemical techniques was made to clarify the mechanism by which pentlandite is leached in acid FeCl3 solution. The techniques used included: potentiometry, linear sweep cyclic voltammetry, intermittent galvanostatic polarization, chronopotentiometry and chronoamperometry. The products were analysed using scanning electron microscopy, powder X-ray diffraction, electron microprobe analysis, atomic absorption spectroscopy and gravimetric analysis. The fitting of experimental results to a simple electron transfer model via the Sand equation was tested and found to be inappropriate. A mechanism for the oxidative dissolution of pentlandite is postulated. In acid solution, pentlandite decomposes spontaneously, liberating aqueous metal ions and H2S. Under potentiostatic conditions akin to FeC13 leaching, pentlandite is oxidized directly to elemental sulphur, without the formation of any intermediate phases. The lack of formation of violarite indicates that the system is substantially perturbed from equilibrium due to slow solid state diffusion of metal atoms within the sulphur sublattice. The formation of metastable amorphous sulphur as the alternative product is further evidence of this perturbation. The physical properties of the sulphur product layer cause an impediment to mass transport between the bulk aqueous solution and the mineral surface. However, the oxidation involves an intrinsically slow 'electron transfer for the So, Fe2+, Ni2+ / Fe4.5Ni4.5S8 couple which, within the potential range relevant to FeCl3 leaching, is rate determining for an appreciable part of the reaction. The implication for extractive hydrometallurgy is discussed. The use of a convolution transform of voltammetric currents with a (πt)-1/2 function as applied to simple electron transfer is described. In addition, the derivation of a functional form for the treatment of chronoamperometric data is given. These models were applied in the determination of the heterogeneous electrochemical parameters and diffusion coefficients for the FeC13/FeC12 couple in 1M HC1 solution on platinum at 293K, using computer controlled chronoampermetric techniques. The results show quasi-reversible behaviour (at 293K), which implies that electron transfer for this couple would not be rate determining in the leaching of pentlandite.
3
Parker, Andrew Donald. "Oxidative dissolution of chalcopyrite in ferric media: an x-ray photoelectron spectroscopy study." Thesis, Curtin University, 2008. http://hdl.handle.net/20.500.11937/140.
Abstract:
The oxidative dissolution of chalcopyrite in ferric media often produces incomplete copper recoveries. The incomplete recoveries have been attributed to inhibition caused by the formation of a metal deficient sulphide and the deposition of elemental sulphur and jarosite. Although these phases have been qualitatively identified on the surface of chalcopyrite, none have been quantitatively identified. The aim of the project was to quantitatively analyse the surface before and after oxidative dissolution, with X-ray photoelectron spectroscopy (XPS), and to use the phases identified as the basis for mechanisms of dissolution and inhibition.XPS analysis was performed on chalcopyrite massive fractured under anaerobic atmosphere and chalcopyrite massive and concentrate oxidised in 0.1 M ferric sulphate (pH 1.9) and 0.2 M ferric chloride (pH 1.6) at 50, 65 and 80ºC. Quantitative XPS analysis of the chalcopyrite surfaces required the development of programs that accounted for the observed XPS spectra. The output of these programs was used to construct profiles of the chalcopyrite surfaces and the deposited phases. These surface profiles were correlated with copper recoveries determined for chalcopyrite concentrate dissolution under the same conditions.The surface of chalcopyrite before oxidative dissolution reconstructs to form a `pyritic' disulphide phase. This phase is oxidised in ferric media to form thiosulphate via the incorporation of oxygen atoms from the hydration sphere. The thiosulphate reacts in the oxidising conditions of low pH to form elemental sulphur, sulphite and sulphate. The sulphate complexes with ferric to produce hydronium jarosite. This reaction occurs at the surface during the initial stages of dissolution and in the bulk solution during the latter stages. This precipitation of hydronium jarosite during the latter stages of dissolution corresponds to inhibition of the dissolution reaction. It is therefore concluded hydronium jarosite is responsible for inhibiting the oxidative dissolution of chalcopyrite in ferric media.The identification of hydronium jarosite as the inhibiting phase is consistent with the industrial practice of removing `excess' iron from the ferric solution before oxidative dissolution. However, additional iron and sulphate are generated at the chalcopyrite surface during oxidative dissolution. These high iron and sulphate concentrations combine with the low pH and high temperatures favoured for the oxidative dissolution of chalcopyrite to produce ideal conditions for jarosite precipitation. Therefore, pH must be lowered further to prevent jarosite precipitation and enhance copper recoveries from chalcopyrite in ferric media.
4
Parker, Andrew Donald. "Oxidative dissolution of chalcopyrite in ferric media: an x-ray photoelectron spectroscopy study." Curtin University of Technology, School of Science and Computing, 2008. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=118673.
Abstract:
The oxidative dissolution of chalcopyrite in ferric media often produces incomplete copper recoveries. The incomplete recoveries have been attributed to inhibition caused by the formation of a metal deficient sulphide and the deposition of elemental sulphur and jarosite. Although these phases have been qualitatively identified on the surface of chalcopyrite, none have been quantitatively identified. The aim of the project was to quantitatively analyse the surface before and after oxidative dissolution, with X-ray photoelectron spectroscopy (XPS), and to use the phases identified as the basis for mechanisms of dissolution and inhibition.XPS analysis was performed on chalcopyrite massive fractured under anaerobic atmosphere and chalcopyrite massive and concentrate oxidised in 0.1 M ferric sulphate (pH 1.9) and 0.2 M ferric chloride (pH 1.6) at 50, 65 and 80ºC. Quantitative XPS analysis of the chalcopyrite surfaces required the development of programs that accounted for the observed XPS spectra. The output of these programs was used to construct profiles of the chalcopyrite surfaces and the deposited phases. These surface profiles were correlated with copper recoveries determined for chalcopyrite concentrate dissolution under the same conditions.
The surface of chalcopyrite before oxidative dissolution reconstructs to form a `pyritic' disulphide phase. This phase is oxidised in ferric media to form thiosulphate via the incorporation of oxygen atoms from the hydration sphere. The thiosulphate reacts in the oxidising conditions of low pH to form elemental sulphur, sulphite and sulphate. The sulphate complexes with ferric to produce hydronium jarosite. This reaction occurs at the surface during the initial stages of dissolution and in the bulk solution during the latter stages. This precipitation of hydronium jarosite during the latter stages of dissolution corresponds to inhibition of the dissolution reaction. It is therefore concluded hydronium jarosite is responsible for inhibiting the oxidative dissolution of chalcopyrite in ferric media.
The identification of hydronium jarosite as the inhibiting phase is consistent with the industrial practice of removing `excess' iron from the ferric solution before oxidative dissolution. However, additional iron and sulphate are generated at the chalcopyrite surface during oxidative dissolution. These high iron and sulphate concentrations combine with the low pH and high temperatures favoured for the oxidative dissolution of chalcopyrite to produce ideal conditions for jarosite precipitation. Therefore, pH must be lowered further to prevent jarosite precipitation and enhance copper recoveries from chalcopyrite in ferric media.
5
Bourdoiseau, Jacques-André. "Rôle des espèces sulfures sur le comportement d’un acier non allié en milieu de stockage des déchets radioactifs de type C : interaction sulfures / produits de corrosion." Thesis, La Rochelle, 2011. http://www.theses.fr/2011LAROS328/document.
Abstract:
Ce travail de doctorat concerne le stockage des déchets radioactifs à vie longue et haute activité en site géologique profond. Dans le concept actuellement retenu par l’Andra (Agence nationale pour la gestion des déchets radioactifs), c’est une enveloppe en acier non allié, appelée « surconteneur », qui sera au contact de l’environnement. Dans les conditions anoxiques où se retrouvera l’acier après une période initiale relativement courte, des vitesses de corrosion très faibles sont attendues, ce qui garantirait l’intégrité du surconteneur pour des millénaires. Cependant, il n’est pas exclu que des bactéries sulfurogènes puissent se développer à proximité ou au contact du surconteneur et modifier localement la cinétique de la corrosion via les espèces sulfures produites par leur métabolisme. L’objectif de cette thèse consistait à améliorer notre compréhension du système de corrosion constitué de l’acier, de sa couche de rouille essentiellement composée de sidérite FeCO3 et d’un électrolyte sulfuré.Pour ce faire, il a été nécessaire dans un premier temps de caractériser par microspectroscopie Raman les sulfures de fer impliqués dans les processus de corrosion et d’étudier les mécanismes de leur formation et de leur transformation dans différentes conditions de concentration en Fe(II) et S(-II), de pH, de température et d’oxygénation. Il a pu être démontré que le spectre Raman de la mackinawite FeS, composé qui précipite à partir de Fe(II) et S(-II) dissous dans toutes les conditions considérées ici, évoluait avec la cristallinité et l’oxydation du composé. Par ailleurs, les mécanismes de l’oxydation à 80°C en milieu acide anoxique de la mackinawite en greigite Fe3S4 ont pu être décrits. Cette étude a permis de démontrer que les sulfures de fer souvent présents sur les objets archéologiques ferreuxissus de milieux anoxiques sont soit de la mackinawite, soit étroitement apparentés à la mackinawite.Dans un deuxième temps, nous avons étudié la formation de produits de corrosion carbonatés par polarisation anodique d’électrodes d’acier à température ambiante dans des électrolytes désaérés à base de NaHCO3. Les conditions expérimentales permettant d’obtenir la sidérite ont été re précisées et utilisées pour synthétiser des couches modèles de FeCO3 sur acier. Par ailleurs, il a été observé que la rouille verte carbonatée était le principal produit se formant aux faibles concentrations en espèces carbonates (0,003 et 0,1 mol L-1 par exemple),la sidérite se formant aux fortes concentrations (0,5 et 1 mol L-1). Les conditions permettant la formation de la chukanovite, l’hydroxycarbonate de Fe(II) de formule Fe2(OH)2CO3, n’ont pas pu être explicitées, même si cette phase a été obtenue dans un électrolyte contenant à la fois des ions SO42- et HCO3- à la concentration de 0,03 mol L-1.Enfin, les interactions entre sulfures et produits de corrosion ont été étudiées. La sidérite, la lépidocrocite et la goethite sont toutes réactives vis-à-vis des sulfures. Ainsi, il apparaît clairement que les espèces sulfures produites par les BSR devraient interagir avec la couche de produits de corrosion avant d’interagir avec le métal sous-jacent. Les tests effectués sur des analogues archéologiques du 16ème siècle, immergés deux mois dans des solutions sulfurées en conditions anoxiques ont permis de le démontrer. Le principal effet de cette immersion a été la formation de sulfures de fer à l’interface entre la couche dense de produits de corrosion, essentiellement constituée de sidérite, et le milieu transformé, zone où s’entremêlent les minéraux propres au sol et ceux produits par la corrosion du fer. Les espèces sulfures n’ont pas été détectées au voisinage immédiat de la surface du métalThis PhD work deals with the nuclear waste disposal. In France, it is envisaged byAndra (French national radioactive waste management agency) that high-level radioactivewastes will be confined in a glass matrix, stored in a stainless steel canister, it self placed in a carbon steel overpack. The wastes will then be stored at a depth of ~500 m in a deep geological repositery, drilled in a very stiff (indurated) clay (argillite) formation. The kineticsof corrosion expected for the overpack in this disposal concept are low and will stay low if the somehow protective rust layer that will develop initially on the steel surface remains undamaged. Local changes of the physico-chemical conditions may however degrade this layer and induce accelerated kinetics of corrosion. In particular, the growth of sulphate reducing bacteria (SRB) close to the steel overpack cannot be excluded and the sulphid especies these micro-organisms produce may modify the corrosion process. The aim of this work was then to achieve a better understanding of the corrosion system constituted with steel, its rust layer mainly made of siderite FeCO3, and a sulphide-containing electrolyte.First, it proved necessary to characterise the iron sulphides involved in the corrosion processes by Raman micro-spectroscopy so as to study their formation and transformation mechanisms in various conditions of Fe(II) and S(-II) concentration, pH, temperature andaeration. It could be demonstrated that the Raman spectrum of mackinawite FeS, thecompound that precipitated in any case from dissolved Fe(II) and S(-II) species with the experimental conditions considered here, depended on the crystallinity and oxidation state.Moreover, the mechanisms of the oxidation of mackinawite into greigite Fe3S4 in acidicanoxic solutions at 80°C could be described. Finally, iron sulphides, often present on archaeological artefacts, could be identified using Raman micro-spectroscopy. The compounds present were mainly mackinawite and greigite.Secondly, to investigate the nature and properties of carbonated rust layers, carbonsteel electrodes were polarised anodically in NaHCO3 electrolytes continuously de-aerated byan argon flow. The experiments were performed at room temperature. The carbonated greenrust was observed to form at 0.003 and 0.1 mol L-1 NaHCO3 whereas FeCO3 was obtained atthe largest concentrations (0.5 and 1 mol L-1). Additional experiments were performed similarly in solutions of NaHCO3 and Na2SO4. Chukanovite, the Fe(II) hydroxycarbonate with formula Fe2(OH)2CO3, could be obtained in solutions containing 0.03 mol L-1 of eachsalt.Finally, interactions between sulphide species and corrosion products were studied.Siderite, goethite and lepidocrocite proved to be reactive towards sulphide. So, it seems clear that sulphide species produced by SRB should interact with the rust layer before to reach the metal underneath. Tests were performed with ferrous archaeological artefacts immersed 2months in anoxic sulphide-containing electrolytes to demonstrate it. The main effect of theimmersion was the formation of iron sulphide at the interface between the dense corrosion products layer, mainly constitute of siderite, and the transformed medium, where minerals ofthe soil are mixed with corrosion products. Sulphide species were not detected at the vicinityof the iron surface
6
Cheng, Terry Chi-Ming 1968. "Production of hematite in acidic zinc sulphate media." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38169.
Abstract:
In this work, the kinetic and equilibrium profiles of each individual reaction step involved in the production of hematite at 200°C via oxydrolysis of ferrous sulphate in concentrated zinc sulphate media were established. Crystallization of ferrous sulphate was found to play a crucial role in the overall process due to its relatively low solubility and fast crystallization kinetics at elevated temperatures. In fact, the overall kinetics of the oxydrolysis process were found to be limited by the re-dissolution of ferrous sulphate. Pre-crystallization of ferrous sulphate prior to oxidation was found to result in enhanced overall kinetics, cutting down the required retention time from 3 to 2 hours. Enhanced kinetics were also achieved by performing oxydrolysis in two-temperature stages: a low temperature (T = 180°C) first stage with retention time >20 min and an elevated temperature (T = 200°C) second stage with retention time >100 min.The typical composition of the hematite material produced in this work was 64.3% Fe, 1.3% S (as SO4), 0.6% Zn, and 4.6% H2O. The sulphur content was found to be predominantly (0.6--0.8%) due to formation of sodium jarosite with the remaining (0.3--0.5%) attributed to SO4 chemisorption, and (to less extent) basic ferric sulphate formation. In the absence of zinc sulphate, the majority of sulphate contamination was due to basic ferric sulphate formation. Hematite was found to form via a predominantly homogeneous nucleation mechanism with sub-micron crystallites clustered together as aggregates of 5--10 mum size and around 7 m 2/g specific surface area. In contrast, hematite produced by direct hydrolysis of ferric sulphate possessed one order of magnitude higher specific surface area. As for the industrial hematite product, its composition was found to be 52.6% Fe, 4.6% S, 1.0% Zn, and 8.8% H2O. The sulphur contamination in the industrial product was mainly due to co-precipitation of jarosite and basic ferric sulphate compounds. Hydrothermal trans-formation of the industrial hematite product at elevated temperatures (>200°C) and retention time of >60 min with solids loading as high as 16 wt.% proved to be effective in reducing the sulphur content to less than 1%.
7
Quezada, Reyes Víctor Alejandro. "Pretreatment to the leaching of copper sulphides minerals in oxidizing media." Doctoral thesis, Universitat de Barcelona, 2021. http://hdl.handle.net/10803/670663.
Abstract:
La producción chilena de cobre procede de la hidrometalurgia y la concentración; el concentrado de cobre es tratado tradicionalmente mediante pirometalurgia. De acuerdo a Cochilco, el cobre producido en el año 2019, vía hidrometalurgia, fue un 27.3% del cobre chileno producido. Sin embargo, se prevé que esta aporte baje a un 11.6% para el año 2029, debido al agotamiento de los óxidos de cobre y la aparición de los sulfuros, principalmente calcopirita, siendo este mineral refractario a condiciones convencionales de lixiviación.
Una opción para mejorar la eficiencia de lixiviación es el pretratamiento, especialmente el efecto del tiempo de curado. Esta variable mejora la cinética de disolución, principalmente en minerales sulfurados de cobre, sin embargo, existe escasa investigación al respecto. Estudios sobre el pretratamiento evalúan el efecto en la eficiencia de lixiviación pero no antes. Además, las reacciones que gobiernan estos fenómenos no han sido identificadas. Así, el objetivo de esta tesis es la evaluación del efecto del curado ácido en la extracción de cobre desde minerales sulfurados en condiciones oxidantes y en la presencia de cloruro.
Muestras puras de calcopirita, calcosina y un mineral industrial de mina han sido utilizadas. Se desarrollaron pruebas evaluando el efecto del tiempo de curado y la concentración de KNO3, NaCl y H2SO4 y analizadas por ANOVA (calcopirita). Los productos formados en el pretratamiento (aglomerados) se caracterizaron utilizando diversas técnicas, tales como: Difracción de rayos X, Microscopio electrónico de barrido y Microscopia de luz reflejada. Además, el efecto del pretratamiento ha sido evaluado en la eficiencia de lixiviación a varias temperaturas, los residuos de lixiviación también han sido caracterizados.
En el pretratamiento, el mineral de calcopirita y de mina, bajo las condiciones utilizadas en este estudio (15 kg/t of H2SO4, 25 kg/t of NaCl y 15 días de tiempo de curado), los siguientes productos fueron identificados: CuSO4, NaFe3(SO4)2(OH)6, Cu2Cl(OH) y S. Sobre la calcosina, bajo las condiciones utilizadas en este estudio, con 30 kg/t of H2SO4, 40 kg/t of NaCl y 7 días de tiempo de curado, los productos identificados fueron: Cu1.75S, Cu(OH)Cl, Na2SO4 and CuSO4. Finalmente, el pretratamiento mejora la eficiencia de lixiviación, entre 4 y 6%, alcanzando una extracción de cobre de 94% desde la calcopirita a 90 °C, fortaleciendo la hidrometalurgia como alternativa de tratamiento para minerales sulfurados de cobre.Copper production in Chile is developed by hydrometallurgical and concentration; copper concentrates are traditionally treated by the pyrometallurgical route. According to Cochilco, copper produced in 2019 by hydrometallurgical process represent a 27.3% of Chilean total copper production. However, this contribution is estimated to decrease to 11.6% by 2029, due to the depletion of copper oxides and the appearance of copper sulphides, mainly chalcopyrite, being this mineral refractory to conventional leaching conditions. An alternative to improve leaching efficiency is pretreatment prior to leaching, especially the effect of curing time. This variable can increases the kinetics of copper extraction, especially in sulphides ores, however, there is limited research about it. Studies on pretreatment evaluate the effect on leaching efficiency but not previous leaching. Furthermore, the reactions that govern this phenomenon have not been clearly identified. Therefore, the objective of this thesis is the evaluation of the effect of acid curing on the copper extraction from sulphides minerals in oxidizing media and in presence of chloride. A pure sample of chalcopyrite, chalcocite and a mine ore were used. Tests evaluating the effect of curing time, KNO3, NaCl and H2SO4 concentration have been carried out. The chalcopyrite sample effect was evaluated by ANOVA. The product generated in the pretreatment (agglomerates) has been characterized using different characterization techniques, such as: X-Ray diffraction, Scanning Electron Microscopy and Reflection Optical Microscopy. Furthermore, the effect of pretreatment has been evaluated on the leaching efficiency at different temperatures, leaching residues have also been characterized. In the pretreatment of the chalcopyrite sample and mine ore, under the conditions of 15 kg/t of H2SO4, 25 kg/t of NaCl and 15 days of curing time, the following products were identified: CuSO4, NaFe3(SO4)2(OH)6, Cu2Cl(OH) and S0. Regarding the chalcocite sample, under the conditions of with 30 kg/t of H2SO4, 40 kg/t of NaCl and 7 days of curing time, the following products were identified: Cu1.75S, Cu(OH)Cl, Na2SO4 and CuSO4. Finally, copper sulphides ore pretreatment improved leaching efficiency, between 4 and 6%, reaching a copper dissolution of 94% from chalcopyrite at 90 °C, strengthening the hydrometallurgy as an alternative treatment for copper sulphides ores.
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Guida, Manrique Leydy Carolina. "Mécanismes contrôlant la séquestration du gadolinium, du rhénium et du sélénium dans des conditions de faible teneur en oxygène." Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALU015.
Abstract:
Les éléments traces, malgré leur rareté (moins de 100 parties par million) sur Terre, remplissent diverses fonctions : certains agissent comme des micronutriments, tandis que d'autres, appelés métaux critiques, possèdent des applications industrielles et médicales uniques. Dans les systèmes aquatiques naturels dépourvus d'oxygène, les transferts d'électrons impliquent des réactions biogéochimiques catalysées par le fer, le soufre et les éléments traces. Comprendre leur réactivité dans ces environnements reste un défi. Ma recherche de doctorat se concentre sur combler cette lacune de connaissance concernant trois éléments spécifiques (rhénium (Re), sélénium (Se) et gadolinium (Gd)). Ils existent sous diverses formes chimiques aqueuses dans l'eau : anion monovalent (perrhénate, ReO4—), anion divalent (sélénate, SeO42— et sélénite, SeO32—) ou cation (gadolinium, Gd3+). Le rhénium est un métal critique, tandis que le sélénium est un élément bioessentiel à faibles niveaux et devient toxique à des concentrations plus élevées. Le gadolinium est un élément des terres rares et un métal critique également, en raison de son utilisation étendue comme agent de contraste dans l'imagerie par résonance magnétique (IRM).Ces éléments sont les plus concentrés dans les sédiments marins formés dans des environnements dépourvus d'oxygène. Les phases minérales courantes comprennent la pyrite (FeS2) et la magnétite (Fe3O4), selon la teneur en sulfure dans ces environnements et l'origine (autogène vs détritique, par exemple, à partir de roches volcaniques) des particules. Ma recherche, présentée sur quatre chapitres, étudie les processus de réduction de surface (Re(VII), Se(VI) et Se(IV)) et la sorption (Gd(III)) sur/dans les particules de magnétite et de pyrite. En utilisant diverses méthodes analytiques telles que la spectroscopie XAFS, la spectroscopie STEM-EELS et le MC-ICP-MS, notre étude révèle des voies réactives distinctes. Re(VII) réagit avec l'eau sulfurée pour former des nanoparticules de Re(III, IV, V)2S7, tandis qu'à des concentrations plus faibles, le Re est réduit et incorporé dans les particules, selon des voies caractérisées par une fraction isotopique moindre avec la pyrite qu'avec la magnétite. Nous montrons également que les nanoparticules de pyrite réduisent le Se(VI) et le Se(IV), jusqu'à obtenir du Se(0) en surface ou du Se(-I) en structure, selon que l'adsorption ou la co-précipitation se produit. Enfin, le Gd se substitue au Fe(III) dans les nanoparticules de magnétite jusqu'à une substitution de 5% de Fe par Gd. Nous tentons d'unifier le comportement d'affinité de ces éléments traces et d'autres avec les sédiments riches en Fe anoxiques à la lumière du principe des acides et des bases durs et mous.L'étude apporte de nouvelles perspectives sur les mécanismes qui régissent la séquestration des métaux et métalloïdes dans les environnements sédimentaires. La signification de cette recherche réside dans sa pertinence pour les entreprises scientifiques et technologiques contemporaines, en particulier pour comprendre comment les processus dans les systèmes riches en Fe et en sulfures fonctionnent, tels que les éléments traces, la mobilité du Fe et du S, l'équilibre des masses dans les cycles sédimentaires mondiaux, jusqu'à l'exploration, l'exploitation minière et le recyclage des gisements potentiels de métaux. De plus, elle améliore notre compréhension actuelle de l'utilisation des proxies paléoenvironnementaux pour reconstruire la formation de la Terre. Enfin, cette étude a également des implications pour le traitement des déchets nucléaires et de la pollution, en particulier dans la gestion de la contamination par le sélénium (Se) et le gadolinium (Gd)Trace elements, despite their scarcity (less than 100 parts per million) on Earth, serve diverse purposes: some act as micronutrients, while others, known as critical metals, possess unique industrial and medical applications. In oxygen-deprived natural aquatic systems electron transfers involve biogeochemical reactions catalyzed by iron, sulfur and trace elements. Understanding their reactivity in these environments remains a challenge. My Ph.D. research focus on filling this knowledge gap concerning three specific elements (rhenium (Re), selenium (Se), and gadolinium (Gd)). They exist in various chemical aqueous species in water: monovalent anion (perrhenate, ReO4—), divalent anion (selenate, SeO42—and selenite, SeO32—) or cation (Gadolinium, Gd3+). Rhenium is a critical metal, while selenium is a bioessential element at low levels, and becomes toxic in higher concentrations. Gadolinium is a rare earth element and a critical metal as well, due to its wide use as a contrast agent in magnetic resonance imaging (MRI).These elements are most concentrated in marine sediments formed in oxygen-deprived environments. Common mineral phases include pyrite (FeS2) and magnetite (Fe3O4) depending on sulfide content in those environments, and origin (autogenic vs. detritic, e.g., from volcanic rocks) of the particles. My research, presented across four chapters, investigates surface reduction (Re(VII), Se(VI) and Se(IV)) and the sorption (Gd(III)) processes on/into magnetite and pyrite particles. Employing various analytical methods such as XAFS spectroscopy, STEM-EELS spectro microscopie and MC-ICP-MS, our study reveals distinct reactive pathways. Re(VII) reacts with sulfidic water to form Re(III, IV, V)2S7 nanoparticles, while at lower concentrations Re is reduced and incorporated into particles, in different pathways characterized by less isotopic fractionation with pyrite than with magnetite. We also show that pyrite nanoparticles reduce Se(VI) and Se(IV), down to surface Se(0) or structure Se(-I) depending on whether adsorption or co-precipitation occurs. Lastly, Gd substitutes for Fe(III) in magnetite nanoparticles up to 5% Fe substitution by Gd. We attempt to unify the affinity behaviour of these and other trace elements with anoxic Fe-bearing sediments in the light of the hard and soft acids and bases principle.The study provides new insights into the mechanisms that govern the sequestration of metals and metalloids in sedimentary settings. The significance of this research lies in its relevance to contemporary scientific and technological endeavours, particularly in understanding how processes in Fe and sulfidic systems work like trace elements, Fe and S mobility, mass balance in the global sedimentary cycles to the exploration, mining and recycling of potential repositories of metals. Furthermore, it enhances our current understanding of the use of palaeoenvironmental proxies to reconstruct the Earth's formation. Finally, this study also has implications for the treatment of nuclear waste and pollution, particularly in the management of selenium (Se) and gadolinium (Gd) contamination
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Singhania, Shalabh. "On the precipitation and stability of scorodite produced from sulphate media at 950C." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33345.
Abstract:
Arsenic is a major contaminant in the non-ferrous extractive metallurgical industry and its disposal poses a serious environmental threat. Precipitation of arsenic from aqueous acidic solutions in the form of crystalline scorodite (FeAsO4.2H2O), which is a naturally-occurring mineral, is proposed as an arsenic fixation method. The production of scorodite is usually done in autoclave at high temperature and pressure. However, in a breakthrough at McGill University, a step-wise neutralization procedure has been developed where scorodite can be formed at ambient pressure (95°C). This work investigates the relation between precipitation conditions in sulphate media with the crystallinity, yield, and above all, solubility of scorodite produced. This work has investigated the effect of (1) type of seed, (2) type of base, (3) cationic and anionic additives, (4) Fe/As ratio, and (5) presence of Fe(II) in the precipitation media. It was found that crystalline scorodite can be produced via the use of various types of seed such as hematite and gypsum in addition to scorodite. The stability of the product was not found to be affected measurably upon change of base from MgO to CaO and in the presence of various cations (Cu, Zn, Ni, Co, and Mn) and anions (sulphate, nitrate and phosphate). Most solubilities measured were between 1 and 3 mg/L at pH 5. Solubilities as low as 0.5 mg/L were found when Fe(III):As(V) was 3:1 but the yield was low. Following these results, Fe(II) was added to the system and solubilities as low as 0.2 ppm were observed with yields of over 80% in a single precipitation step.
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De, Klerk Richard. "Investigating the continuous circuit coprecipitation of arsenic(V) with ferric iron in sulphate media." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21969.
Abstract:
This thesis presents the results of an investigation on the impact of continuous circuit and solution parameters on coprecipitation of arsenic with ferric iron from acidic sulphate solution. The techniques employed were selected, or developed, to emulate industrial practice. The concept behind the work was to better understand the link between the process of precipitation and the stability of arsenic in the resultant coprecipitates. This was performed by examining the role of circuit design and co-ions on both arsenic removal during coprecipitation and arsenic retention during ageing. The parameters/factors investigated included continuous versus batch operation, number of stages (pH profile), recycling and Ca2+, Ni2+ and Al3+ as co-ions. Arsenic removal was found to be greatly improved by continuous rather than batch coprecipitation. In addition, the presence of calcium (introduced as slaked lime) was found to be instrumental in the removal and retention of arsenic. Arsenic retention during ageing (up to 300 days) at various temperatures (3, 22, 40 and 70°C) was observed to reach an "equilibrium" that was strongly affected by the continuous circuit design, as well as the co-ions present during coprecipitation. Evidence is presented of the partitioning of arsenic within the coprecipitates in two principal phases, namely ferric arsenate (FeAsO4•xH2O) and arsenic adsorbed ferrihydrite. Continuous circuit design parameters, such as staging, that resulted in enhanced stability appear to yield coprecipitates with higher ferric arsenate content. Analysis of the kinetic and "equilibrium" arsenic retention data yielded activation energy (~ 60 kJ/mol) and enthalpy (~ -38.5 kJ/mol) values that suggest a reaction controlled exothermic dissolution mechanism.Ce mémoire de maîtrise présente les résultats d'une étude portée sur la co-précipitation de l'arsenic et des ions ferriques en solution aqueuse sulfatée. L'utilisation d'un procédé continu et les paramètres de la solution ont été considérés comme cibles d'étude. Les techniques employées ont été sélectionnées ou développées afin de simuler les méthodes opératoires industrielles. L'idée directrice de ce travail était d'aboutir à une meilleure compréhension sur les liens entre les mécanismes de précipitation et la stabilité de l'arsenic dans les co-précipités formés. Aussi, le rôle du design du procédé ainsi que celui des co-ions sur l'extraction, respectivement la stabilisation de l'arsenic ont fait l'objet d'un examen approfondi à court terme soit au stade de co-precipitation, respectivement à long terme durant le vieillissement de la solution. Les paramètres/facteurs étudiés incluaient le caractère continu du procédé (en comparaison avec un procédé discontinu), le nombre d'étapes (le profile pH), le recyclage des produits solides et la nature (Ca2+, Ni2+ et Al3+) des co-ions introduits dans le système. Cette étude a montré que l'utilisation d'un procédé continu (en comparaison avec un procédé discontinu) améliorait considérablement l'extraction de l'arsenic à partir de solutions aqueuses sulfatées. Aussi, la présence de calcium (introduit sous forme de chaux hydratée) s'est avérée profitable à l'extraction de l'arsenic à court et à long terme. Il a été observé que la stabilisation de l'arsenic dans le cas des expériences de vieillissement (d'une durée de 300 jours) performées à différentes températures (3, 22, 40 et 70°C) atteignait un état d'équilibre fortement influencé par le design du procédé continu ainsi que par les co-ions présents lors de la co-précipitation. Il a été mis en évidence que lors de la phase de co-précipitation, l'arsenic était réparti sous forme de de
Books on the topic "Sulphide media":
1
Towey, Thomas. Quantum-sized cadmium sulphide colloids prepared in microemulsion media. Norwich: University of East Anglia, 1991.
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Isaacson, A. E. Effect of sulfide minerals on ferrous alloy grinding media corrosion. Washington, D.C: U.S. Dept. of the Interior, Bureau of Mines, 1989.
3
Isaacson, A. E. Effect of sulfide minerals on ferrous alloy grinding media corrosion. Washington, DC: Dept. of the Interior, 1989.
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Redfield, Harry Westfall. Study of Hydrogen Sulphide Production by Bacteria and Its Significance in the Sanitary Examination of Water. Creative Media Partners, LLC, 2018.
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Redfield, Harry Westfall. A Study of Hydrogen Sulphide Production by Bacteria and Its Significance in the Sanitary Examination of Water. Franklin Classics Trade Press, 2018.
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Redfield, Harry Westfall. A Study of Hydrogen Sulphide Production by Bacteria and Its Significance in the Sanitary Examination of Water. Franklin Classics, 2018.
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Covic, Adrian, Mugurel Apetrii, Luminita Voroneanu, and David J. Goldsmith. Vascular calcification. Edited by David J. Goldsmith. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199592548.003.0120_update_001.
Abstract:
Vascular calcification (VC) is a common feature of patients with advanced CKD and it could be, at least in part, the cause of increased cardiovascular mortality in these patients. From a morphologic point of view, there are at least two types of pathologic calcium phosphate deposition in the arterial wall—namely, intima calcification (mostly associated with atherosclerotic plaques) and media calcification (associated with stiffening of the vasculature, resulting in significantly adverse cardiovascular outcomes). Although VC was viewed initially as a passive phenomenon, it appears to be a cell-mediated, dynamic, and actively regulated process that closely resembles the formation of normal bone tissue, as discovered recently. VC seems to be the result of the dysregulation of the equilibrium between promoters and inhibitors. The determinants are mostly represented by altered calcium and phosphorus metabolism, secondary hyperparathyroidism, vitamin D excess, high fibroblast growth factor 23, and high levels of indoxyl sulphate or leptin; meanwhile, the inhibitors are vitamin K, fetuin A, matrix G1a protein, osteoprotegerin, and pyrophosphate. A number of non-invasive imaging techniques are available to investigate cardiac and vascular calcification: plain X-rays, to identify macroscopic calcifications of the aorta and peripheral arteries; two-dimensional ultrasound for investigating the calcification of carotid arteries, femoral arteries, and aorta; echocardiography, for assessment of valvular calcification; and, of course, computed tomography technologies, which constitute the gold standard for quantification of coronary artery and aorta calcification. All these methods have a series of advantages and limitations. The treatment/ prevention of VC is currently mostly around calcium-mineral bone disease interventions, and unproven. There are interesting hypotheses around vitamin K, Magnesium, sodium thiosulphate and other potential agents.
Book chapters on the topic "Sulphide media":
1
Guocai, Zhu, Fang Zhaoheng, and Chen Jiayong. "Leaching of gold from sulphide concentrates with thiosulphate/polysulphide produced by disproportionation of elemental sulphur in ammoniacal media." In Hydrometallurgy ’94, 541–46. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-1214-7_34.
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Dutrizac, J. E., and T. T. Chen. "Reaction of galena in ferric sulphate—sulphuric acid media." In Hydrometallurgy ’94, 125–38. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-1214-7_7.
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Loto, Roland Tolulope, Richard Leramo, and Babatunde Oyebade. "Inhibition Effect of Essential Oil Extracts on the Corrosion Inhibition of Mild Steel in Chloride–Sulphate Media." In TMS 2019 148th Annual Meeting & Exhibition Supplemental Proceedings, 939–48. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-05861-6_92.
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Loto, Roland Tolulope, Cleophas Akintoye Loto, Akanji Olaitan, and Olufunmilola Joseph. "Effect of Heat Treatment on the Localized Corrosion Resistance of S32101 Duplex Stainless Steel in Chloride/Sulphate Media." In TMS 2019 148th Annual Meeting & Exhibition Supplemental Proceedings, 959–66. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-05861-6_94.
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Coleman, G. S. "Anaerobic protozoa and fungi." In Anaerobic Microbiology, 279–96. Oxford University PressOxford, 1991. http://dx.doi.org/10.1093/oso/9780199632046.003.0014.
Abstract:
Abstract There are many different species of’anaerobic’ amoebae, flagellates, and ciliates although they differ considerably in their degree of aerotolerance. For example. Entamoeba histolytica grows in semi-solid media containing a reducing agent such as cysteine or ascorbic acid but without any other anaerobic precautions, whereas the rumen ciliates (e.g. Enwdinium caudmum) will only grow in media from which all dissolved oxygen has been removed, which contain a reducing agent, and which have O2-frcc gases in the headspace above the medium. Anaerobic protozoa are found in a variety of habitats such as the sapropel (the ecosystem at the bottom of fresh or marine waters that contains decomposing organic material and which is rich in sulphide), the hind gut of termites and other xylophagous insects, the reticulorumen of ruminants such as sheep, cows, deer, antelope, giraffe, etc., the hind gut and caecum of many herbivorous animals, and the intestines and genitourinary tract of many animals.
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"Bismuth sulphite agar." In Culture Media for Food Microbiology, 266–68. Elsevier, 1995. http://dx.doi.org/10.1016/s0079-6352(05)80024-4.
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"Iron sulphite agar." In Culture Media for Food Microbiology, 332–34. Elsevier, 1995. http://dx.doi.org/10.1016/s0079-6352(05)80045-1.
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"Bismuth sulphite agar." In Handbook of Culture Media for Food Microbiology, 413–15. Elsevier, 2003. http://dx.doi.org/10.1016/s0079-6352(03)80034-6.
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"Iron sulphite agar." In Handbook of Culture Media for Food Microbiology, 487–89. Elsevier, 2003. http://dx.doi.org/10.1016/s0079-6352(03)80058-9.
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"Sulphite Cycloserine Azide (SCA) agar." In Culture Media for Food Microbiology, 445–47. Elsevier, 1995. http://dx.doi.org/10.1016/s0079-6352(05)80084-0.
Conference papers on the topic "Sulphide media":
1
Baghapour, Shaghayegh, Jasmine Nehema, Wen Q. Zhang, Stephen C. Warren-Smith, Shane M. Hickey, Sally E. Plush, and Sharaam Afshar. "Hydrogen Sulphide Detection Using a Fibre Optic Platform." In Optical Fiber Sensors. Washington, D.C.: Optica Publishing Group, 2023. http://dx.doi.org/10.1364/ofs.2023.th6.5.
Abstract:
In this study a fibre-optic platform for detecting hydrogen sulphide in aqueous media was developed. The fibre tip was coated with a synthesised fluorescent probe which showed a fluorescence intensity enhancement upon H2S exposure. XPS confirmed coating uniformity and presence.
2
Al-Mithin, Abdul Wahab, Abdul Wahab Al-Ahmad, Vinayak Sardesai, and G. Santhosh Kumar. "Integrity Management of Aged Equipment in Sour Oil and Gas Service: Kuwait Oil Company Approach." In ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25115.
Abstract:
The professionals across the Oil & Gas industry have strived to combat the adverse effects of Hydrogen Sulphide and maintain the integrity of vital facilities. The detrimental effects of Hydrogen Sulphide on process equipment has remained as one of the prime subject of research in Oil & Gas Industry, fostering the advancement of inspection philosophies and necessitating adoption of appropriate mitigating measures. The challenge of Integrity Management increases with the ageing of equipment and increased influx of sour media. This paper discusses: • The change in operating environment — from non sour to sour. • The actions taken to protect the equipment in the changed operating environment. • Consequent changes in the inspection strategies and techniques to detect material degradation. • Material protection methodologies deployed to manage the age old facilities for safe operation. This paper gives an insight into the various methodologies adopted in KOC to address asset/plant life extension issues of an operating company to tackle the challenges caused by the changed composition of fluids handled. The paper illustrates adoption of appropriate inspection strategies, application of effective internal coating systems, periodic online monitoring of the pressure vessels to improve confidence level with respect to integrity of the vessels without necessitating major changes in the facilities.
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Schmidt, Tanja, Thomas Haase, and Christoph Bosch. "Non-Standard HIC and SSC Testing Under More Severe Test Conditions." In 2012 9th International Pipeline Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ipc2012-90171.
Abstract:
The challenging environment appearing in recent and moreover future deep offshore explorations promoted the development of linepipe steel grades with reliable sour service resistance. Severe sour conditions such as the combination of elevated production temperature, increasing pipeline pressures and high stress loads initiated by modern laying methods or introduced during service are leading to increasing corrosion demands. Steel pipelines used for the transport of media containing wet Hydrogen Sulphide (H2S) are faced with the danger of the cracking phenomena HIC (Hydrogen Induced Cracking) and SSC (Sulphide Stress Cracking). To prove resistance to HIC and SSC, test specimens are typically tested according standardised test methods. The exposure of test specimens in a sour test solution to a H2S pressure of 1 bar for 96 h, as described in NACE TM0284 is used to prove HIC resistance. Commonly four-point bend testing as described in EFC publication no. 16 is performed for SSC resistance testing with the appliance of a specific load, typically 80% of the actual yield strength. Within this work HIC testing at test conditions representing higher H2S partial pressures (up to 5 bar) and longer test durations (up to 6 months) have been performed on seamless quenched and tempered line pipe steel of grade X65 and X70 produced by VALLOUREC & MANNESMANN TUBES by plug and continuous mandrel mill process. Beside material in as delivered condition also pre-strained material was tested. SSC four-point bend testing has been performed on specimens which were strained up to 10% of plastic strain in longitudinal direction.
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Bahaj, A. S. "The effect of concentration and valency of iron sulphate media on the bio-magnetic iron sulphides produced through continuous culture." In IEEE International Magnetics Conference. IEEE, 1999. http://dx.doi.org/10.1109/intmag.1999.837700.
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Chirica, Lazăr. "Starea actuală a geosistemelor din zona de litoral a mării Negre și unele tendinţe." In Starea actuală a componentelor de mediu. Institute of Ecology and Geography, Republic of Moldova, 2019. http://dx.doi.org/10.53380/9789975315593.32.
Abstract:
The Black Sea is a unique basin with a complicated geological history, a hidrobiological regime that has changed much in time and has significant level variation throughout it’s evolution. Is the most important development basin of chemolitoatotrophic bacteria that influences the unprecedented development of hydrogen sulphide (𝐻2S) an anaeropic processes are present, which express the basin’s meromic character.
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Mindubaev, A. Z., E. V. Babynin, E. K. Badeeva, and Y. A. Akosah. "Strain Aspergillus niger AM1 – a living organism resistant to white phosphorus." In 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.172.
Abstract:
Copper sulphate has no effect on the growth of aspergill in a media with white phosphorus. We compared the white phosphorus resistance of A. niger AM1 with three strains from the All-Russian Collection of Microorganisms. Highest resistance was observed in AM1.
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"The Kinetic Dissolution of Copper from Chalcopyrite-containing Carbonatite Tailings Samples in Sulphate Media." In Nov. 18-19, 2019 Johannesburg (South Africa). Eminent Association of Pioneers, 2019. http://dx.doi.org/10.17758/eares8.eap1119256.
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Mellbring, G., J. Chotai, and T. K. Nilsson. "PLASMA DEHYDROEPIANDROSTERONE SULPHATE CONCENTRATIONS AND DEEP VEIN THROMBOSIS AFTER MAJOR ABDOMINAL SURGERY." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644208.
Abstract:
Dehydroepiandrosterone sulphate (DHEAS) is a major secretory product of the human adrenal gland. Its precise functions are uncertain, but it has been postulated as a discriminator of life expectancy and aging. We have previously reported significantly lower plasma levels of DHEAS pre- and postoperatively in men developing DVT after major abdominal surgery, as compared to patients who remained free of DVT. Recent data suggest that the DHEAS concentration is also independently and inversely related to death from cardiovascular disease in men over 50 years of age. We here report data on preoperative plasma concentrations of DHEAS (measured with RIA) in 96 patients over 40 years of age, who underwent major abdominal surgery, and correlated the result to the development of postoperative DVT as diagnosed by the 125I-fibrinogen uptake test.Thirty patients (31%) developed postoperative DVT during the first ten postoperative days. The plasma levels of DHEAS were significantly lower in the patients with postoperative DVT compared to those without (median 1.95 umol/1; Q1−Q3, 1.30−3.00 vs. median 3.35 umol/1; Q1−Q3 1.60−4.70; p < 0.02). Ninety per cent of the patients who developed postoperative DVT had a DHEAS value lower than 3.9 umol/1, while 45 % of the patients who remained free of DVT had a DHEAS value higher than 3.9 umol/1.In conclusion, the data suggest that a low preoperative value of DHEAS predisposes the development of postoperative DVT in patients undergoing major abdominal surgery. It seems like the DHEAS concentration in plasma can be a valuable factor in a predictive index for postoperative DVT in those patients.
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Ortega, José Marcos, María Dolores Esteban, Mark Williams, Isidro Sánchez, and Miguel Ángel Climent. "Effects of Silica Fume on the Pore Structure and Properties of Mortars Exposed to Sulphate Aggressive Media." In The 3rd International Electronic Conference on Materials Sciences. Basel, Switzerland: MDPI, 2018. http://dx.doi.org/10.3390/ecms2018-05231.
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"Mineralogical Observation Made During the Kinetic Dissolution Study of Chalcopyrite Mineral in Sulphate Media under Free pH at Room Temperature." In Nov. 19-20 2018 Cape Town (South Africa). Eminent Association of Pioneers, 2018. http://dx.doi.org/10.17758/eares4.eap1118240.