Recovery of chromium(VI) from electroplating effluent by solvent extraction with tri-n-butyl phosphate

Abstract

Recovery of hexavalent Chromium from a model and real electroplating effluent by solvent extraction with tri-n-butyl phosphate (TBP) was studied. In different acid media chromium(VI) extraction with TBP followed the order HCl > H2SO4 similar to HNO3. In acidic chloride medium chromium(VI) was extracted as HCrO3Cl.2TBP. The loading capacity of TBP for chromium(VI) was found to be 5.35 g/L. Stripping of chromium(VI) from loaded TBP was also studied. With 0.1 N NaOH solution chromium(VI) was stripped quantitatively from loaded organic. TBP was also used to recover chromium(VI) and zinc from electroplating effluent collected from an electroplating industry. By simultaneous extraction with TBP, and stripping with 10% H2SO4 and 1N NaOH zinc and chromium(VI) were recovered, quantitatively.