| 摘要 |
PURPOSE:To enable methane fermentation by charging seed sludge contg. methane fermentation bacteria to the excess sludge discharged in the stage of activated sludge treatment of waste water generated in paper industry, adding further tailing of pulp to adapt the methane fermentation bacteria. CONSTITUTION:Excess sludge obtd. by the activated sludge treatment of waste water generated in paper industry, is fed to a methane fermentation tank. Seed sludge contg. methane fermentation bacteria is charged thereto, and 2-3pts.wt. pulp tailing basing on 1pt.wt. excess sludge is added further. Thus, the methane fermentation bacteria is adapted and methane fermentation is caused. The digested liquid produced by the methane fermentation is circulated for reuse to the aeration tank for the activated sludge treatment. Although enormous amt. of energy and cost have been required for the dehydration and incineration of excess slurry in the prior art, the recovery of energy, nitrogen and phosphorus are realized by this invention. Closed systems for N and P are established and the excess sludge is decomposed without dehydration treatment. Therefore, the treatment of the finally discharged sludge from the bottom of a methane fermentation tank has become very simple.
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