The Effect of Coagulation on Preventing UF Membrane from Fouling

摘要

In this experiment,the effects on improve of flux and prevention of membrane from fouling was studied.The results demonstrated that after backwashing,the flux was completely recovered by addition of 4mg/L and 10mg/L (as Al) ,while the flux was only 40% of initial flux without coagulation pretreatment.It was also found that whether or not prevention of fouling by coagulation was depended on the characteristics of cake layer formed on membrane surface during membrane filtration.In the presence of filtration of coagulation floc suspension,coagulation could form cake layer on membrane surface,thus prevent membrane from fouling effectively,while in the presence of filtration of supernatant,fouling was occurred due to cake layer comprising small,neutral,hydrophilic compounds,which can not removed by backwash.