| 摘要 |
<p>PROBLEM TO BE SOLVED: To conserve energy, to reduce waste and to decrease the consumption of chemicals. SOLUTION: The sludge settled in a settling tank 19 is introduced (returned) into a return-sludge reaction tank 3 having a settling part 6 in the rear in this waste water treating device. As a result, the unreacted chemicals contained in the sludge settled in the settling tank 19 is reutilized in the reaction tank 3, and the unreacted chemicals are never discharged as sludge. Accordingly, the generation of sludge is drastically decreased as compared with the conventional waste water treating method in which sludge is drawn off from the settling tank 19, and the disposal cost of sludge, the consumption of slaked lime and the running cost such as the maintenance cost of the dehydrator are reduced.</p> |
