Effect of aggregated floc circulation on Membrane fouling in contact circulated coagulation-membrane filtration hybrid process for treatment of surface water

摘要

The effect of aggregated floc circulation on membrane fouling in contact circulated coagulation-membrane filtration hybrid process for treatment of surface water was investigated in this study. In order to understand the floc characteristics, the floc formation, breakage and re-growth were monitored by Mastersizer 2000 under the coagulation dosage of 5, 10, 15 and 20mg/l.A contact circulated coagulation tests were carried out and the effluentwas filtered by a dead-end micro-filtration with the hollow fibre membrane. The coagulation effluentquality and the relative permeability J/Joof membrane was determined at the circulated floc dosage of 22, 44 and 66mg/l. The experiment results indicated that the addition of circulated floc obviously improved the flux decline and the degree of improvement was closely related to the dosage of circulated floc. Compared to traditional coagulation, the contact circulated coagulation was an economic and efficient method to retard the membrane fouling.