WASTEWATER TREATMENT METHOD

摘要

PROBLEM TO BE SOLVED: To provide a wastewater treatment method that can reduce the clogging of an MF membrane with a hypochlorite and suppresses a hypochlorite wastewater from being generated.SOLUTION: The wastewater treatment method including the steps of a flocculation settlement process that performs flocculation settlement process on wastewater discharged from an incineration plant with a flocculant to obtain a supernatant water, a microfiltration membrane separation process that separates and removes the supernatant water with a microfiltration membrane, and a microfiltration washing process that washes the upstream side of the microfiltration membrane with a hypochlorite aqueous solution where the hypochlorite is contained so as to lower the inter-membrane differential pressure of the microfiltration membrane increased by performing the microfiltration membrane separation process, wherein the microfiltration membrane washing process is performed so as to satisfy B≤1.47×A+59.2 at the time of starting the steps if it is assumed that the inter-membrane differential pressure of the microfiltration membrane is A (kPa) and the hypochlorite concentration of the hypochlorite aqueous solution is B (mg/L).