活性污泥中的水分测定及其脱水性能

Moisture distribution and dewaterability of activated sludge

活性污泥通常都难于脱水,造成其处理处置上的困难.对于日益增长的污泥排放量而言,改善其脱水性能是目前亟待解决的一个重要课题.从了解污泥的结构与水分的分布特征出发,进而开发新型的预处理工艺来提高污泥的脱水率是解决污泥处理问题的一条正确途径.在参考大量文献的基础上汇总了活性污泥中水分分布的测定方法,并对污泥脱水性能的评价指标及其意义进行了系统介绍.最后,详细讨论了污泥脱水性能的影响因素及作用机理,包括胞外聚合物的影响,以及酸处理、阳离子絮凝、超声处理、热处理等预处理工艺对污泥脱水性能的影响.

Activated sludge is generally difficult to be dewatered,which poses problems for the subsequent treatment and disposal of activated sludge.Due to the ever-increasing production of this waste,improving the dewaterability of activated sludge becomes an important issue to be concerned.To achieve better dewatering of activated sludge,it is necessary to understand the characteristics of sludge structure and moisture distribution,thus develop effective pre-treatment processes.This paper summarizes the commonly used measurement methods for the moisture distribution in activated sludge.The main indexes uses for evaluating the dewaterability of activated sludge and their implications are also systematically introduced.The influences of various factors on the dewaterability of activated sludge and corresponding mechanisms are discussed in detail,including the influence of extracellular polymeric substances of activated sludge,and the influences of pre-treatments such as acid treatment,flocculation by cations,ultrasonic treatment and thermal treatment.