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PILOT PLANT EVALUATION OF ALTERNATIVE ACTIVATED SLUDGE SYSTEMS
Citation:
Heidman, J. PILOT PLANT EVALUATION OF ALTERNATIVE ACTIVATED SLUDGE SYSTEMS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-77/108.
Description:
Step feed, plug flow and complete mix activated sludge systems were compared on a pilot plant scale under similar operating conditions with the same municipal wastewater. The process loading to each system was varied over a wide range during the course of the investigation. Extended periods of steady state operation at constant flow provided extensive data on effluent quality, sludge yield, settling characteristics, etc. at several fixed F/M loadings for each of the system configurations. All systems demonstrated that the variability in carbonaceous effluent quality was mostly influenced by the suspended solids concentrations in the effluent over a wide range of process loadings. Sludge production was the same within experimental error in all systems at comparable SRT's. Analysis of the aggregate data from all systems produced a yield coefficient of 0.79 g VSS/g BOD5 applied and a decay coefficient of 0.064/day. The sludge from the complete mix system exhibited the poorest settling characteristics. A step feed system was found to offer the best physical arrangement for secondary treatment of District of Columbia wastewater.