| 摘要 |
<p>PURPOSE:To efficiently reduce BOD and COD in waste water, by connecting treatment tanks each equipped with a digestion chamber and a sedimentation chamber between a raw waste water introducing side and a final treated waste water side along a flow passage direction successively in series in a multistage fashion. CONSTITUTION:The concn. of waste water is lowered to about 50ppm in the digestion chamber of a treatment tank 1B and the waste water from this treatment tank 1B is withdrawn by a pipe 10 as the supernatant solution of a sedimentation chamber 4 to be introduced into the digestion chamber 3 of a final third stage treatment tank C. In this digestion chamber 3, final treatment is performed by bacteria grown and propagated under the nutritive condition of this introduced waste water in the same way as treatment tanks 1A, 1B and, as a result, the aforementioned BOD concn. of 50ppm is reduced to about 5ppm and waste water is withdrawn from the upper part of the sedimentation chamber 4 by a pipe 11 to be discharged to the outside of the apparatus.</p> |
