TREATMENT METHOD USING REVERSE OSMOSIS MEMBRANE

摘要

Disclosed is an efficient treatment method using a reverse osmosis membrane, which removes contaminants from water to be processed containing contaminants by means of a simple structure and simple operation, while also rendering the water inert and preventing contamination and degradation of the reverse osmosis membrane. Some cooling water from a cooling water system (1) is drawn into a tank for water to be treated (11) and an aqueous solution of a combined chlorine agent is added thereto. In a pre-processing step (10): water to be processed is supplied to a coagulation tank (12), a filtration tank (13) and an activated carbon treatment tank (14) in the presence of free chlorine; coagulation treatment, solid-liquid separation and activated carbon treatment are carried out; and the total chlorine concentration of the pre-treated water is made to be 3-10mg/L and the free chlorine concentration is made to be 0.2-10g/L. In a membrane separation step (20): before pre-treated water is introduced into a pre-treated water tank (21) a reducing agent such as sodium hydrogensulfite is added thereto; and the total chlorine concentration and free chlorine concentration of the pre-treated water are reduced to zero. Then, a combined chlorine agent is added to the pre-treated water tank (21), the total chlorine concentration of the pre-treated water is adjusted to 1-5mg/L and the free chlorine concentration is adjusted to 0.1mg/L or less, and the pre-treated water is treated using the reverse osmosis filter (24).