TREATMENT METHOD OF PHOSPHORIC ACID-CONTAINING WASTEWATER AND TREATMENT AGENT OF PHOSPHORIC ACID-CONTAINING WASTEWATER

摘要

PROBLEM TO BE SOLVED: To provide a treatment method of phosphoric acid-containing wastewater for highly removing the total phosphoric acid from wastewater containing phosphorous acid and hydrophosphorous acid.;SOLUTION: A zirconium compound or the zirconium compound and a sulfuric acid compound are added to wastewater containing phosphorous acid and hypophosphorous acid to hydrolyze the zirconium compound in wastewater and the pH of the wastewater is succeedingly held to 10 or below to insolubilize phosphorous acid and hypophosphorous acid contained in the wastewater. As the zirconium compound, zirconium oxychloride or the like can be used and it is especially preferable to set the pH of wastewater to 7 or below. Orthophosphoric acid may be contained in wastewater. Insolubilized phosphorous acid and hypophosphorous acid may be subjected to solid-liquid separation. Further, treated wastewater free from turbidity can be obtained by adding a sulfate.;COPYRIGHT: (C)2006,JPO&NCIPI