Mechanism of Dual-polymer-flocculated systems and Sludge Dewatering
In order to explore the effect of floc characteristics on the dewaterability of activated sludge conditioned by dual polymer,the floc characteristics and thedewaterability was expressed by the two-dimensional fractal dimensions Df and the filtrating speed and moisture content of sludge cakes, respectively. The image analysis was employed to work out the two-dimensional fractal dimensions Df of different flocculation time. The results indicated the sludge flocculation process could be characterized by the fractal dimensions Df and average diameter daquantitatively. The dual conditioning process was much easier to control and more effective to improve the sludge dewaterability, comparing with the single conditioning process. The floes of sludge pre-conditioned by Fe3+ and followed with CPAM (Fe3+-CPAM) were large and tightly packed within a two-dimensional fractal dimension Df of 1.90 after settling 30mins. The dewaterability of the sludge was the best with the fastest filtrate speed of 3.01ml/s. After pressure filtrating 40mins,the moisture content of sludge cake was only 68.14％. To improve the sludge dewaterability and lower the moisture content of sludge cake, it was significant to obtain large and tightly packed sludge floes by conditioning. In practical operations, this could be reached by sludge dual conditioning which sludge was firstly conditioned by coagulant with rich cations and followed with pol) electrolytes abundant in branched-chain, tail-chain and long-chain. Based on the above results, A physical flocculation model was established to explicit the mechanism of the sludge dual conditioning process. This work may provide theoretical guidance for studyingon mechanisms of sludge flocculation and optimal control of sludge conditioning.
sludge dual conditioning floe characteristics fractal sludge dewaterability flocculation model
Shifu GE Peitao ZHAO Zhenqian CHEN
Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education School of Energy & Environment, Southeast University Nanjing 210096, China
国际会议
三峡
英文
1634-1638
2012-05-18（万方平台首次上网日期，不代表论文的发表时间）