ABSTRACT
Predator-prey interactions are quite common in many natural ecosystems as well as in waste treatment bioreactors. The study of predation is therefore important for understanding the dynamics of ecosystems and is also important for the optimization of the biological treatment of wastes. In activated sludge reactors, for instance, protozoa is known to play a valuable role by preying on unflocculated bacteria and thereby clarifying the reactor effluent [41].
