FRESH WATER GENERATION SYSTEM AND FRESH WATER GENERATION METHOD

WIPO Patent Application WO/2015/046613

A1

Provided is a bactericide addition method for suppressing increasing biofouling by mixing water to be treated with a different water quality in order to reduce energy required to generate fresh water in a fresh water generation system. A fresh water generation system is provided with: a first bactericide addition unit that adds a bactericide to water to be treated (A1) to thereby obtain water to be treated (A2); a second bactericide addition unit that adds a bactericide to dilution water (B1) the salt concentration of which is lower than that of the water to be treated (A1) and the organic matter concentration and/or nutrient salt concentration of which is higher than that of the water to be treated (A1) to thereby obtain dilution water (B2); a mixing unit that mixes the dilution water (B2) into the water to be treated (A2) to thereby obtain mixed water; a third bactericide addition unit that adds, to the mixed water, a bactericide having an amount shown by the expression of (XA+XB)