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Sulfide

About: Sulfide is a(n) research topic. Over the lifetime, 29998 publication(s) have been published within this topic receiving 555518 citation(s). The topic is also known as: sulphide & sulfanediide.

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Journal ArticleDOI
Abstract: Pore water profiles of total-CO 2 , pH, PO 3− 4 , NO − 3 plus NO − 2 , SO 2− 4 , S 2− , Fe 2+ and Mn 2+ have been obtained in cores from pelagic sediments of the eastern equatorial Atlantic under waters of moderate to high productivity. These profiles reveal that oxidants are consumed in order of decreasing energy production per mole of organic carbon oxidized ( O 2 > manganese oxides ~ nitrate > iron oxides > sulfate). Total CO 2 concentrations reflect organic regeneration and calcite dissolution. Phosphate profiles are consistent with organic regeneration and with the effects of release and uptake during inorganic reactions. Nitrate profiles reflect organic regeneration and nitrate reduction, while dissolved iron and manganese profiles suggest reduction of the solid oxide phases, upward fluxes of dissolved metals and subsequent entrapment in the sediment column. Sulfate values are constant and sulfide is absent, reflecting the absence of strongly anoxic conditions.

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2,865 citations


Journal ArticleDOI
01 Jan 1980-Chemical Geology
Abstract: Three hundred new samples of marine evaporite sulfate, of world-wide distribution, were analyzed for δ34S, and 60 of these also for δ18O in the sulfate ion. Detailed δ34S age curves for Tertiary—Cretaceous, Permian—Pennsylvanian, Devonian, Cambrian and Proterozoic times document large variations in δ34S. A summary curve for δ18O also shows definite variations, some at different times than δ34S, and always smaller. The measured δ34S and δ18O correspond to variations in these isotopes in sulfate of the world ocean surface. The variations of δ18O are controlled by input and output fluxes of sulfur in the ocean, three of which are the same that control δ34S: deposition and erosion of sulfate, and deposition of sulfide. Erosion of sulfide differs in its effect on the S and O systems. δ18O in the sulfate does not seem to be measurably affected by equilibration with either seawater or with subsurface waters after crystallization. In principle, the simultaneous application of both δ34S and δ18O age curves should help reduce the number of assumptions in calculations of the cycles of sulfur and oxygen through geological time, and a new model involving symmetrical fluxes is introduced here to take advantage of the oxygen data. However, all previously published models as well as this one lead to anomalies, such as unreasonable calcium or oxygen depletions in the ocean—atmosphere system. In addition, most models are incapable of reproducing the sharp rises of the δ34S curve in the late Proterozoic, the Devonian and the Triassic which would be the result of unreasonably fast net sulfide deposition. This fast depletion could result from an ocean that has not always been mixed (as previously assumed in all model calculations).

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1,633 citations


Journal ArticleDOI
04 Aug 2000-Science
TL;DR: Mass-independent isotopic signatures in Precambrian rocks indicate that a change occurred in the sulfur cycle between 2090 and 2450 million years ago, implying that atmospheric oxygen partial pressures were low and that the roles of oxidative weathering and of microbial oxidation and reduction of sulfur were minimal.

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Abstract: Mass-independent isotopic signatures for delta(33)S, delta(34)S, and delta(36)S from sulfide and sulfate in Precambrian rocks indicate that a change occurred in the sulfur cycle between 2090 and 2450 million years ago (Ma). Before 2450 Ma, the cycle was influenced by gas-phase atmospheric reactions. These atmospheric reactions also played a role in determining the oxidation state of sulfur, implying that atmospheric oxygen partial pressures were low and that the roles of oxidative weathering and of microbial oxidation and reduction of sulfur were minimal. Atmospheric fractionation processes should be considered in the use of sulfur isotopes to study the onset and consequences of microbial fractionation processes in Earth's early history.

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1,420 citations


Journal ArticleDOI
Abstract: Bioleaching of metal sulfides is caused by astonishingly diverse groups of bacteria. Today, at least 11 putative prokaryotic divisions can be related to this phenomenon. In contrast, the dissolution (bio)chemistry of metal sulfides follows only two pathways, which are determined by the acid-solubility of the sulfides: the thiosulfate and the polysulfide pathway. The bacterial cell can effect this sulfide dissolution by “contact” and “non-contact” mechanisms. The non-contact mechanism assumes that the bacteria oxidize only dissolved iron(II) ions to iron(III) ions. The latter can then attack metal sulfides and be reduced to iron(II) ions. The contact mechanism requires attachment of bacteria to the sulfide surface. The primary mechanism for attachment to pyrite is electrostatic in nature. In the case of Acidithiobacillus ferrooxidans, bacterial exopolymers contain iron(III) ions, each complexed by two uronic acid residues. The resulting positive charge allows attachment to the negatively charged pyrite. Thus, the first function of complexed iron(III) ions in the contact mechanism is mediation of cell attachment, while their second function is oxidative dissolution of the metal sulfide, similar to the role of free iron(III) ions in the non-contact mechanism. In both cases, the electrons extracted from the metal sulfide reduce molecular oxygen via a complex redox chain located below the outer membrane, the periplasmic space, and the cytoplasmic membrane of leaching bacteria. The dominance of either At. ferrooxidans or Leptospirillum ferrooxidans in mesophilic leaching habitats is highly likely to result from differences in their biochemical iron(II) oxidation pathways, especially the involvement of rusticyanin.

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968 citations


Journal ArticleDOI
Mahalingam Ravichandran1Institutions (1)
01 Apr 2004-Chemosphere
TL;DR: The ability of organic matter to enhance the dissolution and inhibit the precipitation of mercuric sulfide, a highly insoluble solid, suggests that DOM competes with sulfide for mercury binding, confirmed by very high conditional stability constants for mercury-organic sulfur (RSHg+) complexes (10(25)-10(32)) recently reported in literature.

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Abstract: Dissolved organic matter (DOM) interacts very strongly with mercury, affecting its speciation, solubility, mobility, and toxicity in the aquatic environment. Strong binding of mercury by DOM is attributed to coordination of mercury at reduced sulfur sites within the organic matter, which are present at concentrations much higher than mercury concentrations found in most natural waters. The ability of organic matter to enhance the dissolution and inhibit the precipitation of mercuric sulfide, a highly insoluble solid, suggests that DOM competes with sulfide for mercury binding. This is confirmed by very high conditional stability constants for mercury-organic sulfur (RSHg+) complexes (10(25)-10(32)) recently reported in literature. DOM appears to play a key role in the photochemical reduction of ionic mercury to elemental mercury and subsequent reoxidation of elemental mercury to ionic mercury, thus affecting volatilization loss and bioavailability of mercury to organisms. DOM affects the production and bioaccumulation of methylmercury, the most bioaccumulative mercury species in fish.

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966 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202245
2021969
20201,228
20191,372
20181,237
20171,219

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Topic's top 5 most impactful authors

Akitoshi Hayashi

45 papers, 1.8K citations

Edward M. Ripley

39 papers, 2K citations

Chusi Li

34 papers, 2K citations

Sarah-Jane Barnes

32 papers, 1.6K citations

George W. Luther

31 papers, 1.8K citations