ABSTRACT

During the last ten years there has been increasing interest in the fate and impact of inhibitory organic compounds in the activated sludge process. Although many such compounds are biodegradable at low concentrations, they may be inhibitory to their own biodegradation or to the biodegrada-tion of normal, biogenic, organic matter when their concentration is high. Nevertheless, as long as their input to the activated sludge process can be held constant, their biodegradation will usually proceed without problems, maintaining their concentration low, and allowing uninhibited process performance. Problems arise, however, during the nonconstant input of inhibitory compounds because large shock loads can result in transient increases in their concentration that are severe enough to disrupt treatment efficiency. Thus, an important question facing the design engineer is how to minimize the impact of shock loads.