DEVICE FOR MEMBRANE SEPARATION TYPE ACTIVATED-SLUDGE TREATMENT AND METHOD THEREFOR

摘要

Provided are a device and method for membrane separation type treatment with activated sludge in which water to be treated is circulated in an aerobic tank at a flow rate necessary for evenly and stably washing the membrane surfaces, without reducing the effective separation area of the membranes. The device for membrane separation type treatment with activated sludge is equipped with: an aerobic tank in which water to be treated is biologically and aerobically treated with activated sludge held within the tank; an air diffusion means which supplies air necessary for the aerobic treatment; and a membrane separation means immersed within the aerobic tank. The device has, formed therein, a partition by which the membrane separation means is vertically separated from the air diffusion means within the aerobic tank. The partition has: an upper opening through which the ascending flow of the water to be treated caused by air diffusion from the air diffusion means moves laterally under the water surface and comes into the membrane separation means side; and a lower opening through which the ascending flow, which has come into through the upper opening and turned to a descending flow, goes out to the air diffusion means side after passing through the membranes of the membrane separation means.