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  2. Microbial oxidation of sulfur - Wikipedia

    en.wikipedia.org/wiki/Microbial_oxidation_of_sulfur

    The fractionations of oxygen produced by sulfur disproportionation from elemental sulfur have been found to be higher, with reported values from 8 to 18.4‰, which suggests a kinetic isotope effect in the pathways involved in oxidation of elemental sulfur to sulfate, although more studies are necessary to determine what are the specific steps ...

  3. Hybrid sulfur cycle - Wikipedia

    en.wikipedia.org/wiki/Hybrid_sulfur_cycle

    The hybrid sulfur cycle (HyS) is a two-step water-splitting process intended to be used for hydrogen production. Based on sulfur oxidation and reduction , it is classified as a hybrid thermochemical cycle because it uses an electrochemical (instead of a thermochemical) reaction for one of the two steps.

  4. Sulfur cycle - Wikipedia

    en.wikipedia.org/wiki/Sulfur_cycle

    Sulfur can be found under several oxidation states in nature, mainly −2, −1, 0, +2 (apparent), +2.5 (apparent), +4, and +6. When two sulfur atoms are present in the same polyatomic oxyanion in an asymmetrical situation, i.e, each bound to different groups as in thiosulfate, the oxidation state calculated from the known oxidation state of accompanying atoms (H = +1, and O = −2) can be an ...

  5. Contact process - Wikipedia

    en.wikipedia.org/wiki/Contact_process

    The mechanism for the action of the catalyst comprises two steps: Oxidation of SO 2 into SO 3 by V 5+: 2SO 2 + 4V 5+ + 2O 2− → 2SO 3 + 4V 4+ Oxidation of V 4+ back into V 5+ by dioxygen (catalyst regeneration): 4V 4+ + O 2 → 4V 5+ + 2O 2−; Hot sulfur trioxide passes through the heat exchanger and is dissolved in concentrated H 2 SO 4 in ...

  6. Sulfur metabolism - Wikipedia

    en.wikipedia.org/wiki/Sulfur_metabolism

    Sulfur is metabolized by all organisms, from bacteria and archaea to plants and animals. Sulfur can have an oxidation state from -2 to +6 and is reduced or oxidized by a diverse range of organisms. [1] The element is present in proteins, sulfate esters of polysaccharides, steroids, phenols, and sulfur-containing coenzymes. [2]

  7. Sulfur-reducing bacteria - Wikipedia

    en.wikipedia.org/wiki/Sulfur-reducing_bacteria

    SO 2− 4 + 4H 2 → H 2 S + 2H 2 O + 2OH −. Sulfide Oxidation. Under aerobic conditions, sulfide is oxidized to sulfur and then sulfate by sulfur oxidizing bacteria, such as Thiobacillus, Beggiatoa and many others. Under anaerobic conditions, sulfide can be oxidized to sulfur and then sulfate by Purple and Green sulfur bacteria. H 2 S → S ...

  8. Sulfur compounds - Wikipedia

    en.wikipedia.org/wiki/Sulfur_compounds

    Sulfur polycations, S 8 2+, S 4 2+ and S 16 2+ are produced when sulfur is reacted with oxidising agents in a strongly acidic solution. [1] The colored solutions produced by dissolving sulfur in oleum were first reported as early as 1804 by C.F. Bucholz, but the cause of the color and the structure of the polycations involved was only ...

  9. Disulfurous acid - Wikipedia

    en.wikipedia.org/wiki/Disulfurous_acid

    Disulfurous acid is, like sulfurous acid (H 2 SO 3), a phantom acid, which does not exist in the free state. [2] In contrast to disulfate (S 2 O 2− 7), disulfite has two directly connected sulfur atoms. The oxidation state of the sulfur atom bonded to three oxygen atoms is +5 and its valence is 6, while that of the other sulfur is +3 and 4 ...