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.