Microbial self‐purification in an experimental continuous‐flow system

Abstract

The decomposition of heterogeneous organic substrate by a. mixed community of bacteria and protozoa was studied· in a cascade with three stages and continuous flow (dilution rate 0.246 day-1 for each stage). Emphasis was put on the development of the community during the first seven days after dosing the substrate. During this period (20°C) no steady state or regular oscillations were achieved in the community structure. The substrate decrease in the whole system was around 70% of the inflow from the third day and the total net production of biomass fluctuated around 30% of the inflowing substrate. The grazing effect of protozoa was most pronounced on attached bacteria and on suspended single bacterial cells.