METHOD AND APPARATUS FOR BIOLOGICAL TREATMENT OF ORGANIC WASTE WATER

摘要

PURPOSE:To obtain a good treatment result with good operation efficiency by a method wherein high concn. org. waste water is subjected to acid fermentation treatment and the treated water due to fermentation and a part of low concn. org. waste water are mixed to be subjected to methane fermentation treatment and the treated water due to methane fermentation and the residual low concn. org. waste water are biologically treated. CONSTITUTION:The high concn. waste water from a high concn. waste water supply pipe 1 is subjected to acid fermentation treatment in an acid fermentation treatment tank 4 and the treated water is sent to an ascending current anaerobic sludge bed (VASB) fermentation tank 5 but diluted with the low concn. waste water of a low concn. waste water supply pipe 2 on the way of a liquid feed pipe 8 to be injected as VASB raw water. Generated malodorous gas is blown in an activated sludge treatment tank 3 to be treated. The VASB raw water is subjected to methane fermentation treatment in the VASB tank 5 and the methane fermentation treatment water is allowed to meet with low concn. waste water at the inlet of the activated sludge treatment tank 3 and diluted therewith to be injected in the activated sludge treatment tank 3. The treated water biologically treated in the activated sludge tank 3 is sent to a treated water tank 10 by a liquid feed pipe 6. If necessary, SS is removed from treated water to inject said water in the treated water tank 10.