Effects of Pressure and Pretreatment by Permanganate/PAC/Coagulant on Algae-Rich Water Treatment with UF (Ultrafiltration) Membrane Process

UF (ultrafiltration) technology has been in progress as an alternative to conventional drinking water treatment of raw water which usually contains algae both in domestic and abroad. But fast decrease of membrane flux and ineffective backwashing are major limitations for application of UF on algae-rich water. Pretreatment by permanganate/PAC (powdered activated carbon)/coagulant and a better range of pressure were chosen to mitigate the limitations. The best range of pressure was about 0.06 Mpa. Membrane fouling was severe when pressure is too high or too low, and the phenomenon became clearer with the increment of algae concentration. Turbidity was less than 0.12 NTU while algae were not detection in effluent of each process. The combination use of coagulant and permanganate was the best pretreatment method for backwashing. The combination use of coagulant and PAC had good removal efficiencies of UV254 and DOC, at 36.36% and 28.28% respectively, it could also remarkably relief the fast decrease of membrane flux.