WASTEWATER TREATMENT DEVICE USING SEPARATION MEMBRANE WITH WHICH RECOVERY OF GRANULES OF ACTIVE MICROORGANISMS IS POSSIBLE AND METHOD FOR TREATING WASTEWATER USING SAME

摘要

Provided are device and method for treating sewage and wastewater, with which recovery of granules of active microorganisms is maximized and a stable quality of treated water is obtained. In a granule recovery vessel, granules of microorganisms exhibiting high activity and non-active solid substances are rapidly separated, and the granules are returned to a reaction vessel in order to secure a high concentration of granules in the process. Non-precipitated inactive solid substances are made to flow into a separation vessel and subjected to filtration in order to obtain excellent treated water. The organism reaction vessel is constituted by an anoxic vessel, an anaerobic vessel and an aerobic vessel, and removes nitrogen and phosphorous in the sewage. Granules of heterotrophic microorganisms are recovered from inactive solid substances and treated water in a granule recovery vessel (1) and returned to a stage prior to the anoxic vessel. The inactive solid substances separated from the heterotrophic microorganisms and treated water are sent to the aerobic vessel. Granules of autotrophic microorganisms are recovered in a granule recovery vessel (2) which is a post-stage of the aerobic vessel and returned to a stage prior to the aerobic vessel. The separated inactive solid substances and treated water are sent to a separation membrane vessel, and the inactive solid substances and treated water are separated in the separation membrane vessel.