| 摘要 |
<p>PURPOSE: To lower a sludge load on a membrane with a compact structure and to efficiently filter waste water over a long term at the time of treating the waste water with a biological fixed bed by dipping a micro-filtration- membrane module in a contact aeration tank and applying suction filtration. CONSTITUTION: When a waste water is treated with a biological fixed bed, a micro-filtration-membrane module is dipped into a contact aeration tank, and the waste water is suction-filtered with the module. In this case, the micro- filtration-membrane module consists of a hollow-fiber membrane module. Namely, a hollow-fiber membrane module assembly formed by combining plural hollow-fiber membrane elements each consisting of a biological fixed bed 3, a hollow-fiber membrane 4 and a fixing member 5 and an aerator 6 are dipped in the waste water 2 in the aeration tank 1. The waste water is treated to obtain a water for miscellaneous use. Since contact aeration and the micro- filtration-membrane module are combined in this way, the sludge load on the membrane is lowered, and the waste water is efficiently treated. The PE, PP, etc., having high elongation are preferably used as the membrane material.</p> |
