Flocculation Mitigation for Ultrafiltration Membrane Fouling Based on Floc Structure Regulation
The self-made PAC-PDMDAAC composite flocculant was used to treat polluted river water.The optimum flocculation reaction conditions such as inorganic-organic component composite ratio,initial pH and slow stirring were studied.The variation of fractal dimension and flocculation index during flocculation process and the mechanism of flocculation pretreatment to alleviate ultrafiltration membrane fouling were systematically analyzed.The experimental results showed that under the optimum reaction conditions of PAC and PDMDAAC mass ratio of 5∶1,initial pH value of 5.0 and slow stirring rate of 80 r/min,the removal rates of turbidity and CODMn were 94.6％and 45.8％,respectively.The composite flocculant can effectively remove humic acid and protein organic matter,and reduce the load of subsequent ultrafiltration treatment.By regulating the structure of flocs,large-sized,dense and shear-resistant flocs can be generated,which can effectively improve the permeability of the filter cake layer,so that the decay rate of the normalized membrane specific flux is significantly slowed down,and the purpose of delaying membrane fouling is achieved.
万方数据
维普
