Laboratory and Pilot Plant Evaluation of Intermittent Loading on Small-Scale Extended Aeration Biological Systems.

摘要

The U. S. Army Corps of Engineers is responsible for designing, constructing, and operating wastewater treatment systems for its recreational areas. The use of these areas by 391 million visitors in 1976 emphasizes the importance and significance of this responsibility. Reducing or eliminating the discharge of organic matter and suspended solids from recreational areas to receiving streams or lakes is of paramount importance in the protection of the environment and the maintenance of acceptable water quality. The importance attached to the production of a stable, high-quality effluent increases the priority to define the performance of a biological treatment system under intermittent loading conditions. The approach used in this study involved development of a mathematical model to predict the performance of a completely mixed activated sludge system under intermittent loading conditions, defined for this study as time-dependent hydraulic and organic loadings. The model was verified first with laboratory data from a bench-scale extended aeration system and then with field data from a prototype extended aeration package treatment plant. Parameters used in developing the study included effluent quality, dissolved oxygen uptake, and other performance indicators related to biomass response to intermittent loading conditions. Results of the laboratory phase of this study indicate that an extended aeration activated sludge system will generally perform satisfactorily under intermittent loading conditions. Biological evaluation of the laboratory systems subjected to intermittent loadings indicated that the animal populations within the reactor were chiefly responsible for the fluctuations in the performance of the system.