Microbiological Process Report Activity of Microorganisms in Organic Waste Disposal

Principles of aerobic and anaerobic treatment of organic wastes were developed in the previous papers of this symposium. The application of these principles to engineering design is discussed in this paper. Although the discussion is restricted to the aerobic treatments, the concepts are equally applicable to anaerobic treatments. Laboratory or pilot plant studies are employed to develop engineering design criteria. Laboratory studies are usually batch treatment operations in which various concentrations of acclimatized sludge are aerated with known quantities of waste. Changes in pertinent characteristics such as BOD, COD, oxygen utilization, and sludge accumulation are noted with time. Relationships between time and concentration can be developed from such data. A pilot plant treats waste continuously, simulating anticipated plant scale operation. Variables such as organic matter loading, air rate, and microbial sludge content are changed under conditions of steady state operation. Pilot plant data statistically analyzed provide a sound basis for scaling up to process design.