| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce operation cost for a process of reducing the volume of excessive sludge generated by biological treatment by the oxidative decomposition thereof by ozone. SOLUTION: A biological water treatment apparatus is equipped with a biological treatment tank 1 for allowing organisms to act on water to be treated to clean water to be treated, a sedimentation tank 2 for sedimenting sludge in the treated water discharged from the biological treatment tank and an ozone treatment tank 4 for treating the sludge discharged from the sedimentation tank with ozone and ozone treatment in the ozone treatment tank is performed in the presence of slag. Due to this constitution, the oxidative decomposition and solubilization of sludge is accelerated by a small amt. of ozone and, by using slag as a catalyst, operation cost can be reduced.</p> |
