| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an apparatus for biologically treating organic waste water, in which the treatment efficiency is improved without deteriorating the quality of the treated water and the amount of the excess sludge to be generated can be reduced.SOLUTION: The apparatus for biologically treating organic waste water includes: a biological treatment tank 1 into which the organic waste water is introduced and in which aerobic biological treatment is performed by using active sludge; a precipitation tank 2 in which the water discharged from the biological treatment tank 1 is subjected to solid-liquid separation to obtain separated sludge and separated water; and a return line 3 for returning at least a part of the separated sludge to the biological treatment tank as returned sludge and further includes: a micro animal separation tank 5 into which at least a part of the separated sludge or the sludge in the biological treatment tank is introduced and in which the introduced sludge is left standing and divided into a supernatant liquid and precipitated sludge; a micro animal storage tank 7 into which the supernatant liquid of the micro animal separation tank 5 is introduced and in which micro animals are stored; and a line 8 for supplying the micro animals in the micro animal storage tank 7 to the biological treatment tank.</p> |
