Kinetics and stoichiometry of sulfide oxidation by sewer biofilms.
Oxidation of sulfide under aerobic conditions by biofilms grown on municipal wastewater in 6 identical pipe reactors was investigated. The biofilms were grown at pH 7.6 and temperatures of 20 and 25 degrees C under aerobic-anaerobic transient conditions with pulse dosing of sulfide in the bulk water. The pulse dosing of sulfide served to simulate conditions in a gravity sewer located downstream of a pressure main. During growth of the biofilms, sulfide was pulse dosed in concentrations of 0, 0.5, 2.0 and 5.0 g Sm(-3) with a frequency of 1h(-1). Based on a series of batch experiments, kinetics and stoichiometry of sulfide oxidation by the sewer biofilms was investigated and a rate equation and a stoichiometric constant proposed. Sulfide oxidation kinetics was significantly faster for biofilms grown at sulfide loadings of 0.5, 2.0 and 5.0 g Sm(-3)h(-1) than for biofilms grown in the absence of sulfide. However, the kinetics of sulfide oxidation was relatively constant for biofilms grown at sulfide loadings above 0.5 g Sm(-3)h(-1). Mass balance calculations of dissolved oxygen and sulfur compounds suggested the oxidation product to be elemental sulfur. Further oxidation of elemental sulfur could not be documented.
Nielsen
Asbjørn Haaning
AH
Section of Environmental Engineering, Department of Life Sciences, Aalborg University, Sohngaardsholmsvej 57, DK-9000 Aalborg, Denmark. ahn@bio.aau.dk
Hvitved-Jacobsen
Thorkild
T
Vollertsen
Jes
J
D018441:Biofilms; D007700:Kinetics; D010084:Oxidation-Reduction; D013440:Sulfides / Q000737:chemistry*
D013440:Sulfides