Separation Science and Technology, Vol.40, No.10, 2125-2137, 2005
Recovery of chromium from electroplating wastewater using DI 2-(ethylhexyl) phosphoric acid
Extraction of chromium (III) using D2EHPA (di 2-ethylhexyl phosphoric acid) in kerosene was carried out. A study was carried out to optimize the conditions, namely pH, carrier D2EHPA, aqueous and organic ratio, and reaction time. The effect of chloride and sulphate concentration on the extraction process was studied. The tri-butyl phosphate (TBP) was used as a phase modifier to facilitate the extraction process. In the stripping process, remarkable amount of chromium was recovered from the loaded organic phase using hydrogen peroxide as a stripping agent. When the stripped organic solution was reused for chromium extraction, it showed appreciable extraction efficiency under optimum conditions. The chromium (VI) present in the electroplating wastewater was reduced to chromium (III) with ascorbic acid, and under optimized conditions the removal of chromium from electroplating wastewater was found to be satisfactory.
Keywords:solvent extraction;chromium (III);di 2-(ethylhexyl) phosphoric acid;tri-butyl phosphate;stripping