Utilization of rice bran to prevent bulking in the activated sludge process

Abstract

Rice bran was evaluated for the prevention of bulking in the activated sludge process. After the addition of rice bran to the aeration tank of a food plant, a decrease in the sludge volume index was observed. Both biochemical oxygen demand and chemical oxygen demand showed significant decreases relative to that before the addition of rice bran. Rice bran accelerated the growth of the effective microorganism and thus inhibited the growth of filamentous organisms that cause bulking. The results suggest that phytic acid in rice bran is useful in controlling filamentous bulking in laboratory-scale investigations.