陈化污泥理化特性对泥饼渗透性的影响研究

开展陈化污泥渗透特性研究对于填埋库污泥脱水减量作业具有重要指导意义。选取了8种不同陈化条件下的污泥,开展了压缩排水试验,测定了陈化污泥上清液中可溶性有机物含量和类型,以及陈化污泥聚合体粒径分布与滤液的Zeta电位,并通过皮尔逊相关性分析研究了陈化污泥各物理化学特性间的相互作用。结果表明,随着上清液中可溶性有机物含量的减少、相对腐质化程度的增高与滤液Zeta电位绝对值的增大,陈化污泥的可渗透性增大。同时,当陈化污泥聚合体趋于稳定和粒径增大时,包裹在聚合体中的有机物不易释放到上清液中,陈化污泥可渗透性增大。另外,由于陈化环境的影响,陈化污泥总有机含量变化与上清液中有机物含量变化缺乏一致性,依据陈化污泥有机质含量判断渗透性会造成错误。最后,建立了陈化污泥比阻的影响模型,对于预处理过程中如何改善陈化污泥渗透性具有参考意义。

Influence of physicochemical properties of aged sludge on the permeability of filter cake

Study of the permeability of aged sludge is important for the drainage reduction of sludge in landfills. Eight kinds of sludge under different aging conditions were taken as samples in the present work. Compression drainage tests were carried out, and the content and type of soluble organic matter in the supernatant were determined. The aggregate size distribution and Zeta potential were also measured. The interactions between the physicochemical properties of aged sludge were analyzed by conducting a Pearson correlation. The results show that the permeability of aged sludge increases with the decrease of soluble organic matter content in the supernatant, the increase of the relative degree of humification and the absolute value of filtrate Zeta potential. Simultaneously, when the aggregate tends to be stable and the particle size increases, the organic matter wrapped in the aggregate is not easy to release into the supernatant, and the permeability of aged sludge increases. In addition, due to the aging environment variations, the change in total organic content of aged sludge lacks of consistency with the change in organic matter content in the supernatant. Judging permeability based on the organic matter content of aged sludge would cause errors. Finally, the influence models of specific resistance of aged sludge were established, which were the reference for improving the permeability of aged sludge in the pre-treatment process.