| 摘要 |
<p>PURPOSE:To prevent raw water from flowing out of a tank, by respectively arranging two anaerobic tanks and two aerobic decomposition tanks so as to allow all of them to communicate with each other in series and recirculating sludge and treatment bacteria to each of the tanks. CONSTITUTION:An inflow pipe 11 is provided so as to be connected to the upper part of a first anaerobic decomposition tank 1 to allow living waste water to flow in said tank 1 and the lower part of the tank 1 is allowed to communicate with the lower part of a second anaerobic decomposition tank 2 by an inverted U-shaped first communication pipe 12. Waste water is contacted with biofilms of anaerobic bacteria formed to a filter material during passage through the first and second anaerobic decomposition tanks 1, 2 and the org. substance in the waste water receives anaerobic decomposition and the solid substance mixed with the waste water is separated. The waste water flows in the intermediate layer part of a first aerobic decomposition tank 3 from the upper part of the second anaerobic tank 2 and further flows in the intermediate layer part of a second aerobic decomposition tank 4. Then, the waste water receives the supply of oxygen by the injection of air from an aeration device and aerobically decomposed by the biofilms of aerobic bacteria adhered to a filter material.</p> |
