| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the quality of processed water by a method wherein when an org. waste water is purified by bioprocessing, a part of a separated sludge after solid-liq. separation of an effluent from a biologically treating process is exposed to an oxygen-contg. gas under the coexistence of activated carbon fine particles and then, it is oxidized with ozone and the ozone-oxidized sludge is returned to the biologically treating process. SOLUTION: An activated sludge slurry 3 discharged from a bioprocessing tank 1 is transferred to a precipitation tank 4 to perform solid-liq. separation and to obtain a purified processed water 5. On the other hand, majority of soperated precipitated sludge 6 is returned to the bioprocessing tank 1 as a returned sludge 7 and powdered activated carbon 9 is added into a part 8 of the precipitated sludge and the mixture is aerated for several days with an oxygen-contg. gas 11 such an air in a sludge aeration tank 10 to digest aerobically and then, the activated carbon coexisting sludge 12 after aeration is fed in an ozone oxidation tank 13 to perform oxidization with ozone. Then, the activated carbon coexisting sludge 15 after ozone oxidation is returned to the biologically treating tank 1, where decomposition is performed and then, it is circulated again in the sludge aeration tank 10 and the ozone oxidation tank 13 to perform repeatedly decomposition to decrease extremely the sludge discharged to the outside of the system.</p> |
