Study on optimization of technical conditions of waste sludge reduction
剩余污泥减量化工艺条件优化研究

Different kinds of sludge produced in the activated sludge system of continuous flow running stably was processed with ultrasound and made back to the system, and the reduction effect of waste sludge was studied. An orthogonal experimental program was designed and carried out to determine the optimal operation conditions. The results of this study shows that the reduction effect of sludge is the best when the mixed sludge processed by energy density of 0.6 W/mL, ultrasonic time of 5 min, and the recycling ratio of ultrasonic sludge of 7/120. And operating the system for one period under the above conditions, the rate of reduction is 96.24%, COD declines to 44 mg/L from 830 mg/L initially, the effluent NH+4-N and TN drop from 62.43 to 2.31 mg/L and 103.19 to 6.52 mg/L, respectively, which have achieved first-degree discharge standard based on discharge standard of pollutants for municipal wastewater treatment plant (GB18918-2002).