Abstract
Effect of synthetic or commercial detergents on purification process for activated sludge was investigated, and the following results were obtained. Considerable obstacle was obstacle on the purification of artificial sewage by the presence of linear alkylbenzene sulfonate (LAS) and it appeared remarkably in alkaline range (pH 8.2). Although 10 ppm of LAS did not effect the sewage purification by activated sludge, addition of more than 50 ppm markedly inhibited the removal rate of protein and LAS. It was found that biodegradation of LAS was inhibited by nutrients added in the sewage but, in spite of the presence of nutrients, higher fatty acid sulfate showed a considerabl high removal of detergent in the sewage. On the other hand about 90% of commercial synthetic detergents was degraded and, in the same manner, the presence of nutrients increased the amount of residual detergent in the supernatant after air-blowing. It was observed that TTC reduction of substrates with activated sludge was slightly inhibited by the addition of LAS in the reaction medium.
