WATER PURIFYING METHOD

摘要

A water purification method is provided to extend whole driving time of a film by decreasing operation pressure increasing rate of the film according to the driving time. A water purification method includes a step for supplying raw water into a precise filtering layer or an ultrafiltration membrane with film permeate flux of 25LMH(0.025m^3/m^2.h) or 40LMH(0.04m^3/m^2.h) for initial 30 ~ 120 minutes. And the method includes a steps for supplying the raw water into the precise filtering layer or the ultrafiltration membrane with film permeate flux of 150LMH(0.15m^3/m^2.h) after initial 30 ~ 120 minutes. The water purification method further includes a step for injecting the air and a backwashing process to a reverse direction opposite to a supplying direction.