Reduction of elemental sulfur was studied in the presence and absence of thermophilic sulfur-reducing bacteria, at temperatures ranging from 65 to 110/sup 0/C, in anoxic artificial seawater media. Above 80/sup 0/C, significant amounts of sulfide were produced abiologically at linear rates, presumably by the ...

Reduction of elemental sulfur was studied in the presence and absenc� of thermophilic sulfur-reducing bacteria, at temperatures ranging from 65 to 110�C, in anoxic artificial seawater media. Above 80�C, significant amounts of sulfide were produced abiologically at linear rates, presumably by the ...

Microscopic sulfides with low 34S/32S ratios in marine sulfate deposits from the 3490-million-year-old Dresser Formation, Australia, have been interpreted as evidence for the presence of early sulfate-reducing organisms on Earth. We show that these microscopic sulfides have a mass-independently fractionated sulfur isotopic anomaly (?33S) that differs from that of their host ...

Sulfur species in pore waters of the Great Marsh, Delaware, were analyzed seasonally by polarographic methods. The species determined (and their concentrations in micromoles per liter) included inorganic sulfides (less than or equal to3360), polysulfides (less than or equal to326), thiosulfate (less than or equal to104), tetrathionate (less than or equal to302), organic thiols ...

Microscopic pyrites with low 34S/32S ratios in ~ 3.47-Gyr-old sedimentary barites from North Pole, Australia have been interpreted as evidence for microbial sulfate reduction and/or sulfur disproportionation in the early Archean. We show that these microscopic sulfides have similar to slightly less negative ?33S and slightly more negative ?36S values ...

Nature reduces dinitrogen under mild conditions using nitrogenases, the most active of which contains molybdenum and iron. The only abiological dinitrogen reduction catalyst that avoids the harsh conditions of the Haber-Bosch process contains just molybdenum.

REDUCTION of the soluble, oxidized form of uranium, U(VI), to insoluble U(IV) is an important mechanism for the immobilization of uranium in aquatic sediments and for the formation of some uranium ores1-10. U(VI) reduction has generally been regarded as an abiological reaction in which sulphide, molecular hydrogen or organic compounds ...

Iron disulfide (FeS/sub 2/) minerals in host rocks for roll-type uranium deposits that contain fossil vegetal (organic) matter differ in abundance, distribution, texture, and sulfur isotopic ratios from FeS/sub 2/ minerals in host rocks for deposits that do not contain fossil vegetal matter. In three south Texas deposits lacking such organic matter, preore FeS/sub 2/ is ...

(gce)/kWh); S is the sulfur content in coal (%); R is the sulfur release rate during combustion; and h is the sulfur removal efficiency of the FGD devices, ...

... Descriptors : (*ORGANIC SULFUR COMPOUNDS, *OXIDATION REDUCTION REACTIONS), CHEMICAL BONDS, DISSOCIATION, CATALYSIS ...