METHOD FOR TREATING METAL-CONTAINING WASTEWATER AND TREATMENT SYSTEM FOR METAL CONTAINING WASTEWATER

PROBLEM TO BE SOLVED: To reduce an amount of acid used to adjust pH of alkaline agent or treated water within a range of wastewater standard value, in a method for treating metal-containing wastewater.SOLUTION: A method for treating metal containing wastewater of the present invention includes: a raw water supplying step of supplying metal-containing wastewater into an annular treatment flow path 2; a circulation step of flowing and circulating wastewater 1 supplied into the treatment flow path 2 in a T direction in the treatment flow path 2; a pH adjusting step of adding a pH adjusting agent 5 to the wastewater 1 in the treatment flow path 2 to adjust pH of the wastewater 1; a coagulant adding step of adding coagulant 7 to the wastewater 1 whose pH has been adjusted; a floc collection step of collecting a floc which has aggregated and settled by the coagulant 7; and an electrolysis step of electrolyzing a downstream side circulating water 29 in which the floc is collected, and a supernatant water 17 in which the floc is collected in the treatment flow path 2.SELECTED DRAWING: Figure 1 【課題】金属含有排水の処理方法において、アルカリ剤や処理水のｐＨを排水基準値の範囲内に調整するための酸の使用量を抑える。【解決手段】本発明に係る金属含有排水の処理方法は、環状の処理流路２内に金属含有排水を供給する原水供給工程と、処理流路２内に供給された排水１を処理流路２内でＴ方向に流して循環させる循環工程と、処理流路２内の排水１にｐＨ調整剤５を添加し、排水１のｐＨを調整するｐＨ調整工程と、ｐＨが調整された排水１に凝集剤７を添加する凝集剤添加工程と、凝集剤７によって凝集し沈降したフロックを捕集するフロック捕集工程と、処理流路２内において前記フロックが捕集された下流側の循環水２９と前記フロックが捕集された上澄み水１７とを電気分解する電気分解工程と、を備えている。【選択図】図１