| 摘要 |
Treated water with good water quality which can be discharged or reused is obtained by efficiently removing SS, fluorine, cyanogen, selenium, ammonia, and COD components contained in coal gasification wastewater such as gas washing wastewater generated in a coal gasification step. A method of treating coal gasification wastewater comprising steps (1) to (4), wherein the step (1) is performed prior to the step (2): (1) a fluorine removal step in which fluorine is removed by coagulation sedimentation; (2) a cyanogen decomposition step in which cyanogen is decomposed by wet oxidation or thermal hydrolysis; (3) a selenium treatment step in which selenate ions are subjected to a reduction treatment with a metal reductant; and (4) a COD/ammonia removal step in which COD and/or ammonia are/is removed. |
