| 摘要 |
PROBLEM TO BE SOLVED: To provide a fluorine-containing wastewater treatment method and apparatus which efficiently treat fluorine-containing wastewater to obtain treated water of good quality with a low concentration of residual fluorine, and can reduce the moisture content of sludge generated by the treatment to reduce the amount of the generated sludge. SOLUTION: The fluorine-containing wastewater treatment method comprises a reaction process for adding a calcium compound, and phosphoric acid or its water-soluble salt to the fluorine-containing wastewater to react them at pH of 5-10, a coagulation process for adding a polymer coagulant to the wastewater after the reaction process, a process for performing the solid-liquid separation of coagulated flocs-containing wastewater after the coagulation process, and a sludge return process for returning a part of the sludge subjected to the solid-liquid separation to the reaction process. The calcium compound and an alkali are added beforehand to the return sludge in the sludge return process, and then the sludge is returned to the reaction process. The fluorine-containing wastewater treatment apparatus comprises a reaction tank, a phosphorus supply means, a coagulation tank, a solid-liquid separator, a mixing tank, and a sludge return passage. COPYRIGHT: (C)2006,JPO&NCIPI
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