Separation of congo red by surfactant mediated cloud point extraction

An attempt has been made to remove color from wastewater containing congo red (a toxic cationic dye) by surfactant mediated cloud point extraction (CPE) in batch mode using Triton X-100 (TX-100) as non-ionic surfactant. Most of the dye molecules get solubilized in-the coacervate phase leaving a dye free dilute phase. The effects of the concentration of feed mixture (both dye and surfactant), temperature and salt concentration on the concentration of both dye and surfactant in the coacervate phase and dilute phase have been studied. An optimum set of surfactant concentration, temperature and salt concentration are obtained for removal of dye. Experimental investigations have also been carried out for the recovery of surfactant from dilute phase applying solvent extraction (SE) in batch condition using heptane as extracting medium. (C) 2004 Elsevier Ltd. All rights reserved.