Ref ID : 927
Colin R. Curds; A theoretical study of factors influencing the microbial population dynamics of the activated-sludge process-I. The effects of diurnal variations of sewage and carnivorous ciliated protozoa. Water Research 7:1269-1284, 1973
Reprint
In File
Notes
Mathematical models and computer simulations have been used in examining the theoretical implications of diurnal variations in sewage flow, bacterial content of the sewage, and sewage substrate concentration on the microbial population dynamics and effluent quality of a completely-mixed activated-sludge plant. Variations in sewage substrate resulted in variations in the concentrations of substrate in the effluent and bacteria in the sludge. Variations in the bacterial content of sewage affected only the bacteria-consuming ciliate populations whereas variations in the flow of sewage affected all populations. When all three sewage parameters were varied simultaneously the effect was cumulative. The effects of carnivorous ciliates preying on bacteria-consuming ciliates have been considered for the first time. At least four types of ciliate predator/prey situations could arise since both carnivore and prey can be either free-swimming or attached forms. In general, when the carnivore was a free-swimming form, oscillations, which may or may not dampen, were obtained; when the carnivore was an attached form, the ciliate prey was washed out of the reactor. However, the predictions of the population dynamics of the organisms also depend to a large extent on the values of the various growth constants used.