Stuy On Operating Parameters Optimizing Of A~2/O Process For Domestic Wastewater Treatment

In recent years, sewage treatment rate is rising, but it failed to solve the problem of eutrophication caused by the nitrogen and phosphorus pollution of waste water, therefore, current research in mechanism of biological nutrient removal, influencing factors and process characteristics are hotspots in waste water treatment. A2/O process with simultaneous nitrogen and phosphorus removal function, relative to other processes has the characteristic of simple structure, short hydraulic retention time, low operating costs, small control complexity and difficult to produce sludge bulking, is the best alternative technology in the conventional activated sludge wastewater treatment with nitrogen and phosphorus removal function. The Experiment using a52.15L anaerobic-anoxic-aerobic (A2O) reactor with simulate synthetic wastewater, Culture and Acclimated sludge to start the system, by adjusting the aeration of aerobic units, observing the performance of nitrogen and phosphorus removal under different dissolved oxygen(DO). Experiments show the optimal mixed reflux ratio of200%, the optimal sludge return ratio of80%, the best sludge age of15d, the optimum pH of6.5-7.0. The result of the whole operation show that the system can not keep a high TN removal efficiency under high aeration, and the low aeration made the system a significant decline in pH, nitrogen and phosphorus removal. The removal efficiency was56.52%for TN and71.01%for the TP under the aeration of0.2m3/h, and only24.48%,14%of TN, TP removal under the aeration of0.1m3/h.