| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for treating sulfate ion-contg. waste water by which even waste water having the low content of a sulfate ion is stably and safely treated in high sulfate ion removing efficiency and moreover, the generation amt. of sludge ids decreased. SOLUTION: A calcium component in sulfate ion-contg. waste water is removed in a hardness reducing device 1 and after the waste water is treated by a flocculator 2 and a filter 3, the sulfate ion is concentrated in a membrane separator 4. Then, the filtered water is discharged and after the concd. waste liq. is coagulated by a calcium agent in a coagulator 5, separated into the calcium sulfate-contg. coagulated sludge and the water in a solid-liq. separator 6. The separated water, a liq. separating the coagulated studge generated in accompany with the coagulated sludge treatment, etc., are preferably returned to the hardness reducing device 1 through a return means 7. |
