Abstract: Dewatering performance of sludge modified by CaO and PAFC combined with surfactant is investigated in this study. Water content of dewatered sludge and specific resistance of filtration (SRF) are used to evaluate the sludge dewaterability, and the change of sludge dewaterability is explained by measuring variation of extracellular polymeric substance (EPS) content and Zeta potential in the conditioning process. The results show that adding surfactant can change EPS content in the filtrate, and reduce SRF and water content of dewatered sludge, and improve dewatering performance of sludge. The effect of CaO and PAFC combined with surfactant is better than individual surfactant. The addition of CaO and PAFC can both improve sludge dewaterability and contribute to reduce the addition of surfactant. The content of EPS and its components in sludge filtrate has a high correlation with the water content of dewatered sludge and SRF, and an important effect on the detwatering performance of sludge. The optimal conditions determined by experiment is that the addition amount of CaO, PAFC, surfactant is 66.67 mg·g^-1, 33.33 mg·g^-1, 56.25 mg·g^-1, and the water content in dewatered sludge and SRF are 69.41%、0.294×10¹³ m·kg^-1, respectively.

Key words: waste treatment, coagulation, surfactant, sludge, extracellular polymeric substance, dewaterability

摘要： 研究了CaO、PAFC联合表面活性剂预处理对污泥脱水性能的影响。以污泥滤饼含水率和比阻（SRF）作为评价污泥脱水性能的指标，通过测定污泥调理过程中胞外聚合物（EPS）含量、Zeta电位的变化来阐明污泥脱水性能的变化。实验结果表明，十二烷基二甲基苄基氯化铵（1227）的加入导致上清液中EPS含量发生变化，有效降低了SRF和滤饼含水率，提高污泥脱水性能。CaO、PAFC和表面活性剂的联合调理污泥比单独使用表面活性剂的效果更好，CaO、PAFC的投加不仅改善污泥脱水性能，并有助于减少表面活性剂的用量。污泥上清液中EPS及其各组分含量与污泥滤饼含水率、SRF均有较高的相关性，对污泥的脱水性能有重要贡献。实验中确定的最佳污泥调理条件是CaO投加量为66.67 mg·（g DS）^-1、PAFC投加量为33.33 mg·（g DS）^-1和表面活性剂投加量为56.25 mg·（g DS）^-1，污泥滤饼含水率和SRF分别降至69.41%、0.294×10¹³ m·kg^-1。

关键词: 废物处理, 混凝, 表面活性剂, 污泥, 胞外聚合物, 脱水性能