WATER TREATMENT METHOD AND WATER TREATMENT APPARATUS EACH USING MEMBRANE

Ozonated washing water is generated by injecting an ozone gas into pressurized washing water that is filtered water obtained by membrane filtration of untreated water and that is to be used at the time of backwashing, and the ozonated washing water is supplied to a membrane from the filtration secondary side to thereby remove a fouling substance inside the membrane, while causing ozone containing bubbles (101) to emerge in the filtration primary side to thereby remove a fouling substance on a membrane surface in the filtration primary side. Figure 1.