WATER PURIFYING METHOD

摘要

A water purification method is provided to extend whole operating time of a membrane by decreasing a pressure increasing rate of a membrane according to driving time of a device. A water purification method includes a step for backwashing of a filter membrane by injecting water and the air to a direction opposite to a supply direction. A filtration step is performed by an external pressure-typed whole filtering mode filtering whole raw water from the outside of a precise filtering layer or an ultrafiltration membrane to a vertical direction of a surface of the membrane. In a first or a second step, only the filtration step is performed for 60 minutes to 90 minutes consecutively.