| 摘要 |
Provided is a water treatment method in which impurities such as suspended substances in raw water are efficiently removed using a separation membrane, and in particular clarified water with sufficiently high water quality is stably produced as supplied water of a reverse osmosis membrane unit using a microfiltration membrane or an ultrafiltration membrane. The water treatment method, includes dosing a cationic coagulant to raw water a to form primary coagulated water, using the primary coagulated water as it is as final coagulated water when the zeta potential of the primary coagulated water b is less than 0 mV, or using final coagulated water obtained by dosing an anionic substance so that the zeta potential is less than 0 mV when the zeta potential of the primary coagulated water b is 0 mV or more, and treating the final coagulated water with a separation membrane of which the surface zeta potential is less than 0 mV, to obtain treated water d. |
