超声处理对系统剩余污泥减量效果的研究

Study on Factors of Sludge Reduction in Continuous Flow System by Ultrasonic Waves

在运行稳定的连续流活性污泥系统中采用超声处理剩余污泥并将其返回系统,考察声能密度、超声作用时间和超声污泥回流比对系统剩余污泥减量效果的影响。结果表明,当超声污泥回流比为1∶24、声能密度为0.4 W/mL、超声时间为5 min时,系统污泥日平均产量为13.6 mg/(L.d),减量效果达到95.81%,此时出水COD为73 mg/L、NH4+-N为7.99 mg/L、TN为18.67mg/L,达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)的二级排放标准。此外,系统中污泥的沉降性能及其有机质含量并没有受到显著影响。

The excess sludge produced in the continuous flow activated sludge system operated stably was treated by ultrasonic waves and recycled back to the system. The influence of energy density, ultrasonic time and recycled ratio of ultrasonic sludge on sludge reduction was investigated. The results show that when the recycled ratio of ultrasonic sludge is 1 ： 24, ultrasonic intensity is 0.4 W/mL and ultrasonic time is 5 min, the average sludge production is 13. 6 mg/（ L · d）, the reduction rate is 95.81%, and the effluent COD, NH4 -N and TN are 73 rag/L, 7.99 mg/L and 18.67 mg/L respectively. The effluent quality meets the second level criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant （ GB 18918 - 2002）. In addition, the sludge settleability and organic content in it are not affected obviously.