Reaction mechanism and stoichiometry of biological sulfide oxidation
- Biological oxidation of sulfide is also a multi step process involving a series of biochemical reactions catalyzed by micro-organisms present in sewer biofilm.
- The reaction product of aerobic biological sulfide oxidation is normally the elemental sulfur and other intermediates such as thiosulfate under oxygen-limited conditions. The intermediate products are subsequently oxidized to sulfate, but the rate of this step is much lower than that of the first step.
- Actual oxygen consumption rate of oxygen for biological sulfide oxidation is reported to be higher than 0.5 g O2 per g of S indicating a range of oxidation products.
- Kinetics of biological sulfide oxidation at a low DO is described by different rate equations as follows: