Studies on extraction of chromium(VI) from acidic solution by emulsion liquid membrane

High molecular weight amines, quaternary salts etc. have the potential of removing heavy metal ions including the toxic ones at low concentrations. In the present work an attempt has been made to extract Cr(VI) through emulsion liquid surfactant membrane (or, emulsion liquid membrane-ELM) from it’s acidic solution using alamine-336 and caustic soda as extractant and striping reagents respectively. Around 97% extraction of Cr(VI) from aqueous solutions of potassium dichromate through batch experimentations have been achieved. Being crucial to the overall success of the ELM processes, experiments on emulsion stability have also been performed to arrive at a reasonably stable emulsion composition. Effect of various process parameters such as initial solute concentration, concentration of internal phase etc. as also that of pH on extraction of chromium have been investigated.