城市污水处理过程中污泥的理化特性研究

Study on Physicochemical Properties of Sludge during Municipal Wastewater Treatment Process

为研究城市污水处理过程中污泥理化特性的变化情况,采集了南京市江心洲污水处理厂各处理单元的污泥,分析了各种污泥的含水率、pH、EC、CEC、LOI、TN和TP的含量。结果表明,不同污泥的pH、EC、CEC、LOI、TN和TP含量存在明显差异,且随污水处理流程呈规律性变化。初沉池污泥、脱水前混合污泥和脱水污泥的pH、CEC略高于生化污泥和二沉池污泥的;而EC、LOI、TN和TP则低于生化污泥和二沉池污泥的。二沉池污泥和脱水前混合污泥的理化特性对比结果表明,该污水处理厂最终处理污泥(脱水污泥)的理化特性主要由初沉池污泥的理化特性决定。脱水处理会导致污泥中TP、CEC、pH的下降及EC的升高。

The water contents, pH, EC, CEC, LOI, TN, and TP in sludge sampled from different treatment units of Jiangxinzhou WWTP of Nanjing were analyzed to investigate the variation of physico- chemical properties of sludge along the wastewater treatment process. The results show that significant differences of the pH, EC, CEC, LOI, TN, and TP in sludge can be found among different kinds of sludge, and noticeable change trends can be identified for these properties along the wastewater treatment process. The pH and CEC of primary sludge, mixed sludge, and dewatered sludge are higher than those of biochemical sludge and secondary sludge, while the EC. LOI, TN. and TP show the contrary trends. The comparative results of physicochemical properties between secondary sludge and mixed sludge indicate that the physicochemical properties of the final treated sludge, that is the dewatered sludge, are mainly determined by those of the primary sludge. The dewatering treatment can cause decrease in TP. CEC, and pH and increase in EC of sludge.