| 摘要 |
<p>An organic-containing wastewater is treated by a biological treatment as a step preceding an advanced treatment, e.g., membrane separation treatment. The amount of biological metabolites which generate in the biological treatment is reduced to thereby reduce the amount of organic substances flowing into the advanced treatment step as a later step. Thus, the advanced treatment is made stable and efficient and treated water of high quality is efficiently recovered. Water which has undergone an anaerobic biological treatment in anaerobic reaction tanks (11) comprising an acid generation tank (11A) and a UASB reaction tank (11B) is subjected to a coagulation treatment and then to solid-liquid separation in a first sedimentation tank (14). The water separated therefrom is subjected to an aerobic biological treatment in an aeration tank (21). The water which has undergone the aerobic biological treatment is subjected to a coagulation treatment and then to solid-liquid separation in a second sedimentation tank (24). Thereafter, the resultant water is treated by membrane separation with an RO membrane separator (40) as an advanced means of treatment. By conducting the anaerobic biological treatment, aerobic biological treatment, and solid-liquid separation as steps preceding the advanced means of treatment, organic substances are sufficiently removed to make the treatment with the advanced means stable and efficient.</p> |
