Recovery of chromium(VI) in chromium plating solution by using the cationic surfactant-gel adsorption method

Abstract

The separation and recovery of chromium(VI) by using a cationic surfactant were investigated. Chromium(VI) reacted with cetylpyridinium chloride (CPC) to form a (HCr2O7)(CP) ion-pair under an acidic condition. This ion-pair was sparingly soluble in water, and was separated as a precipitate with CPC from aqueous solution by centrifugation. In order to desorb the chromium(VI) from CP , the reduction of chromium(VI) to chromium(III) having positive charge was performed by using sodium sulfite in the presence of sulfuric acid. Finally, chromium was then recovered as Cr(OH)3 under a basic condition. Optimization for the quantitative recovery of chromium(VI) was carried out. This method was applied to the recovery of chromium(VI) in chrome plating including Cr(III) (VI), Fe, Zn, Cu, Al, Mn and Sb.