| 摘要 |
PROBLEM TO BE SOLVED: To provide a wastewater treatment method with use of a combination system of continuous biological treatment and semibatch biological treatment, capable of suppressing increase in the SS concentration of the treated water by continuous biological treatment.SOLUTION: The wastewater treatment method includes: a continuous biological treatment process for biologically treating objects to be processed in wastewater with microorganism sludge while wastewater continuously flowing into a continuous-type tank 24, and separating the microorganism sludge from the treated water discharged from the continuous tank 24 in a settling tank 26; a semibatch biological treatment process in a semibatch-type tank 14 for repeating an inflowing step for flowing the waste water in, a biological treatment step for biologically treating objects to be processed in wastewater with microorganism sludge, a settlement step for settling the microorganism sludge, and a discharge step for discharging the treated water; and a sludge supply process for supplying the microorganism sludge settled in the semibatch type tank 14 into the continuous-type tank 24. In the discharge step, the treated water is discharged from the semibatch-type tank 14 to the outside of the continuous tank 24 and the settlement tank 26. |
