Method for removing heavy metal such as boron and plating metal from plating wastewater

摘要

PROBLEM TO BE SOLVED: To provide a boron removal method capable of removing about 50 to 100 mg/L of boron in waste water to less than 0.5 mg/L (concentrated pack test value) in stead of a conventional flocculating sedimentation method, which is difficult to remove boron to 10 mg/L or less of drainage standard.;SOLUTION: In the method of forming ettringite in plating drainage containing heavy metals such as boron and plating metal, or adding ettringite to remove the boron and heavy metals in the ettringite by flocculating filtration of the boron and the heavy metals, the ettringite is sulfuric acid, the reaction product is produced by reacting aluminum and calcium chloride as starting materials in an aqueous solution of both components or in plating wastewater to which both components are added, in which the ratio of the aluminum sulfate and the calcium chloride is molar: boron, aluminum A method of removing heavy metals such as boron and plating metal from the plating waste water in which the ratio is 1:4.5-13.5 and boron: calcium=1:7-28.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2019,JPO&INPIT