System and method for preventing ammonia rebound in a cold-weather bioreactor

摘要

A wastewater treatment system and method are provided for preventing or reducing ammonia rebound during periods of warming weather. The system may be operated in first and second modes of operation. During the first mode of operation, wastewater may pass directly from a reactor to a partial mix cell and then to a polishing cell. During the second mode of operation, which typically occurs during a springtime warmup period, wastewater is retained within the partial mix cell until sludge and biosolids therein are substantially digested, while wastewater exiting the reactor is temporarily directed to the polishing cell, thereby bypassing the partial mix cell. Upon digestion and stabilization of the sludge and biosolids in the partial mix cell, the system may return to the first mode of operation. Sludge and biosolids may optionally be removed from the reactor during the first and second modes of operation.