Nickel and cadmium inhibition of activated sludge at extreme substrate levels

Traditionally, mathematical models defining the inhibition of the activated sludge use modified enzyme kinetics. For experimental support, some methods such as the BOD test itself, involve very low substrate concentrations. Others, such as the bacterial growth inhibition test which measures an inhibition potential blocking activity by 50%, use very high substrate concentrations. This paper outlines a series of inhibition experiments with BOD and bacterial growth inhibition tests, using nickel and cadmium as inhibitors. The results are comparatively evaluated by means of appropriate mathematical interpretation.