| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain membrane surface cleaning effects equivalent to seed sludge without adding seed sludge by charging cleaning granules which flow in a tank by the bubble flow of aerating air or a liquid flow caused by the bubble flow and clean the membrane surface of a membrane separator at the start of operation of an aerator for receiving sewage. SOLUTION: A diffusing device 1 in a treatment tank 2 has diffusing holes 4 and communicates with a blower 5 outside the tank 2. As a membrane separator 3, plate-shaped membrane cartridges 7 are arranged at intervals of about 8 mm in the upper part of the case 6. Organic membranes 9 are formed on both sides of a filter plate 8, and a filtrate discharging pipe 10 communicating with a filter channel is installed through a valve device 11. At the start of the operation of the tank 2, with the valve device closed, organic sewage 12 is introduced into the tank 2, and cleaning granules 13 for cleaning the membrane surface of the cartridge 7 are charged. The granules 13, whose specific gravity in water 3 is 1-1.05 and whose particle size is 25-75% of the membrane interval, are charged in an amount of 0.1-5 kg per 1 m<3> of an aerator volume.</p> |
