| 摘要 |
PURPOSE:To dispense with an exclusive washing tank or an exclusive dehydrator and to rationally dehydrate sludge, by mixing separated screen dregs obtained by applying solid-liquid separation to a slurry with sludge generated by org. sewage treatment before applying dehydration treatment to the resulting mixture. CONSTITUTION:A slurry 14 obtained after the treatment of sewage 1 receives solid-liquid separation treatment in a solid-liquid separation process 17 and the liquid component 18 is sent to an aeration tank 9 and treated therein. Washed and separated screen dregs 19 are mixed with concn. sludge 20 concentrated by a thickener 7 and, thereafter, a dehydration additive such as a cationic polymer is added to the resulting mixture if necessary. Next, said mixture is dehydrated by sludge dehydration equipment 21 such as a roll or belt press dehydrator, a centrifugal dehydrator, a vacuum dehydrator or a screw press dehydrator to form a dehydrated cake 22. Furthermore, it is rational to mix separated screen dregs 19 only in excessive sludge 12 without together treating initial precipitated sludge 6 and excessive sludge 12.
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