FRESH WATER GENERATION SYSTEM

摘要

To lessen the number of operations for cleaning a second semipermeable membrane with a chemical or the frequency of replacement of the membrane in a fresh water generation system in which biotreaetd water obtained by biotreating an organic wastewater is filtered with a first semipermeable membrane and the concentrate is mixed with seawater and then filtered with the second semipermeable membrane. [Solution] The present invention is a fresh water generation system (1) equipped with: a first semipermeable membrane device (9) in which biotreated water obtained by biotreating an organic wastewater is filtered with a first semipermeable membrane (8) to thereby separate the biotreated water into a filtrate and a concentrate; and a second semipermeable membrane device (13) in which the concentrate from the first semipermeable membrane device (9) is mixed with seawater and the mixture is filtered with a second semipermeable membrane (14). The first semipermeable membrane (8) is equal to the second semipermeable membrane (14) in the tendency of the water treating microorganism to adhere thereto or the water treating microorganism more readily adheres to the first semipermeable membrane (8) than to the second semipermeable membrane (14).