| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide membrane separation activated sludge treatment equipment where the installation space of membrane modules can be suppressed, and further, the maintenance of membrane faces can be easily performed. <P>SOLUTION: In the outer part of a biological treatment tank 1, membrane modules 4, 5 of circulating and filtering water in the tank are installed in series by a plurality of steps in the upper and lower directions. Each secondary side of the membrane modules 4, 5 in each step is provided with a back washing means in which the flow rate is adjusted in such a manner that the quantity of back washing water in the lower step is made larger than that in the upper step. The adjustment in the flow rate of back washing water is performed by using flow rate control valves or changing the diameter of piping for back washing. The membrane modules 4, 5 installed in series by a plurality of steps preferably lie in the same straight line, and each step can be composed of a plurality of membrane modules connected in parallel. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
