| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce quantity of excessive sludge, in a method for treating org. waste water by utilizing an activated sludge method, by drawing out at least a part of activated sludge to subject bacteria to sterilizing and solubilizing treatment before again introducing the same into an activated sludge treatment system. SOLUTION: In an activated sludge method, org. waste water is pretreated in a conditioning tank to be guided to an aeration tank and an org. pollution component is decomposed herein to be subjected to purifying treatment. Subsequently, the waste water treated within the aeration tank is guided to a sedimentation tank and sedimented activated sludge is returned to the aeration tank as return sludge by the quantity necessary for the purifying treatment of org. waste water. In this case, at least a part of the sedimented activated sludge is further drawn out of the sedimentation tank and this drawn-out activated sludge is subjected to sterilizing and solubilizing treatment without being pretreated. Thereafter, this treated sludge is again introduced into the activated sludge tank along with the return sludge to be circulated. By this constitution, the generation of excessive sludge can be reduced without deteriorating the quality of the treated water.</p> |
