Experimental Study on Minimization of Sludge Production by Ozonation Process

Based on the hypothesis of reducing sludge production under cryptic growth conditions, ozone was used as cell lysis agent to treat excess sludge,and then the ozonated supernatant was returned to the aeration tank. The results show that COD and NH+4-N removal efficiencies in ozonation process were 87.96% and 84.42%, respectively. Meanwhile, a low excess sludge yield coefficient of 0. 113 ( g SS/g COD removed) was obtained. Compared with that of the control test, the process configuration decreased the excess sludge production by 51.3%.