| 摘要 |
The present invention relates to an operation method for a water treatment device comprising a pretreatment unit (X) which changes first water to be treated (A) into treated water (A0) by pretreatment, a membrane separation unit (Y) which separates the treated water (A0) into permeated water (A2) and concentrated water (A3),and a membrane separation unit (Z) which separates mixed water (B1) containing the concentrated water (A3) and/or treated water (A4) of the concentrated water (A3), and second water to be treated (B) and/or treated water (B0) of the water to be treated (B) into permeated water (B2) and concentrated water (B3), the operation method for the water treatment device being characterized by performing at least one method selected from predetermined eight methods when a water quality index (CB3) of the concentrated water (B3) or a water quality index (CB4) of treated water (B4) of the concentrated water (B3) exceeds a predetermined reference value. |
