Abstract
A new biological process for the removal of dissolved sulfide is proposed. The prccess is based on the oxidation of sulfide to elemental sulfur and sulfate by sulfur oxidizing bacteria.
Studies on removal charactistics and sulfur balance were conducted in the labofatory scale experiment. Almost of suifide was converted to sulfate or elemental sulfur and higher efficiency of sulfide removal was obtained at low sulfide load.The datk green colour of the suspended solids in the reactor can be attributed to poly sulfide at high sulfide load. The following results were obtained:
1) .Sulfide removal ratios were higher than 90 percent until the sulfide loading of 417 mg-S2·d-1·l-1.
2) .The maximum sulfide removal rates were approximately 10mg-S2⋅g-SS-1⋅d-1 (per unit of biomass) and 0.4 mg-S2⋅cm-2⋅d-1 (per mit of surface aera of the hollow fiber membrane) .
3) .The persents of sulfur in biofilm and prccipitated solids were 11.3%, 6.1% and 7.0%, 7.9%in reactor 1 and 2, respectively.
4) .Sulfur oxidizing bacteria contaminated from the air foamed the biofiim on the hollow fiber membrane and transformed sulfide into sulfate and elemental sulfur. Inoculation ofbeggiatoa is not necessary.
