Stability of Activated Sludge Agents Under Conditions of Model Sulfur-Containing Wastewater

The results of the study of stability of activated sludge agents to periodically increasing influence of sulfide-ion concentration are presented, the toxic effect of which on flocculus-forming microorganisms causes the effect of biocenosis swelling and, as a consequence, failures in the operation modes of treatment facilities, accompanied by the removal of toxic and nutrients into the hydrographic network. The structure of the community under conditions of sulfur-containing wastewater was studied and succession of dominant agents of activated sludge — predators and protozoa — was established. It was noted that the sanitary functions of activated sludge were preserved in all experiments, which indicates the adaptation of the biocenosis to new ecological conditions.