Estimation of Model Parameters in the Extraction of Cr(VI) from Wastewater by an Emulsion Liquid Membrane

Kinetic modeling of an emulsion liquid membrane for extraction of hexavalent chromium from wastewater was performed. The membrane was prepared by using Span 80, di-(2-ethylhexyl)phosphoric acid (D2EHPA), and kerosene as non-ionic surfactant, carrier, and diluent, respectively. The rate constants of extraction and stripping phases were calculated by studying the effect of the concentration of HCl in the feed, the concentration of the carrier in the membrane, and the pH of the stripping phase. It was found that the rate of complex diffusion due to the difference between the extraction and stripping rates influences the transfer and Cr(VI) buildup in the membrane phase.