Inhibition of Nitrification in the Activated Sludge Process of Sewage Disposal

S ummary . A simple method is described for determining the short term effects of sewages, effluents and individual substances on the nitrifying ability of activated sludge and the results of screening many substances are listed. The effects of mixtures of inhibitors and the possibility of formation of complexes between some of those inhibitors were investigated. The long term effects of inhibitors often differ from their immediate effects, one of the most important factors being the ability of activated sludge to become adapted to the inhibitor.