| 摘要 |
PURPOSE:To dispense with the disposal of sludge, by a method wherein phosphorus and COD-containing waste water is flocculated and separated and, after the incineration residue of flocculated sludge is dissolved by an acid, specific oxide is added to said sludge. CONSTITUTION:An Al-salt such as aluminum sulfate or an Fe-salt 2 such as ferric chloride is added to phosphorus and COD-containing raw water 1, and the COD component and phosphate ion in raw water 1 are flocculated in a flocculation stirring tank 3. The flocculated floc flows in a sedimentation tank 4 to be separated into clarified treated water 5 and flocculated sedimented sludge 6. Excessive activated sludge 7 is mixed with the flocculated sedimented sludge 6 to form a sludge mixture which is, in turn, dehydrated by a sludge dehydrator 8 to obtain a dehydrated cake 9. The dehydrated cake 9 is incinerated in an incinerator 11, and HCl and H2SO4 13 are added to the incineration residue 12 under stirring and the resulting mixture is passed through an adsorbing tower 16 packed with zirconium oxide to adsorb and remove PO4<3->.
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