Surfactant Improving Activated Sludge Dewaterability and Its Mechanism
表面活性剂改进活性污泥的脱水性能及其作用机理

Effects of surfactant used separately or together with ferric chloride and lime water on activated sludge dewaterability and its mechanism were investigated in this paper Results showed that the centrifugal dewatering efficiency could be increased no matter surfactant used solely or plus ferric chloride and calcium oxide.It was observed that when surfactant,ferric chloride and calcium oxide were applied to condition sludge,and vacuum filtrtion was employed to dewater,the water content of dewatered sludge was decreased significantly compared with only ferric chloride and calcium oxide used.To a centrifugal dewatering,the sludge volume,compared with absence of surfactant,was reduced by almost 11% in the case of a 0 109 ratio of surfactant to dry sludge weight.when sludge was preconditioned with surfactant,ferric chloride and lime ahead of filtration,a water content of 78 92% was obtained as the ratio of surfactant to dry sludge was 0 08,which was declined by about 6% compared with just ferric cholride and calcium oxide utilized.Further studies indicated that the mechanisms of surfactant increasing sludge dewaterability were it could improve the sedimentation rate,promote the release of protein and DNA from sludge surface and reduce the amound of interstitial water bounded in the sludge.