Precipitation removal and recovery of Cr(VI) from aqueous solution under hydrothermal condition

Abstract

Chromium removal and recovery from aqueous media which containing various concentration of Cr^VO₄^2- by hydrothermal mineralization treatment were investigated. Hydrothermal mineralizations with CaCl₃ or iron acetate as mineralizer enable effective removal of Cr from aqueous media and it could obtain CaCrO₄ or (Fe_0.6Cr_0.4)₂O₃ with very high concentration. Cr concentrations in the treated-water by both treatments were independent of the initial concentration of Cr. Additionally, the treatment using iron acetate could obtain Fe-Cr-O type natural mineral ((Fe_0.6Cr_0.4)₂O₃) which can be easily reused by industrial resource production system in existence. Thus, the hydrothermal mineralization treatment was one of the effective treatments for Cr removal from wastewater.