Simultaneous biological removal of p-cresol, sulfide and nitrate by denitrification

Biological removal of sulfide, nitrate, and p-cresol at a loading rate of 340 gS/(m(3).d), 340 gN/(m(3).d) and 600 gC/(m(3).d), respectively, was achieved in an upflow anaerobic sludge blanket (UASB) reactor. The ratio of C/S could affect the elemental sulfur (S-0) accumulation, and the C/S ratio of 1.75:1 was optimal for S-0 accumulation. Strains Pseudomonas sp., Simplicispira sp., and Rhizobium sp. could likely yield heterotrophs. Strains Arcobacter sp., Sulfurimonas sp., Sulfurovum sp., and Sulfurospirillum sp. are the autotrophics required for the proposed UASB system. At high loading rate, the autotrophic denitrification pathway declined faster than the heterotrophic pathway.