Cloud point extraction of toxic eosin dye using Triton X-100 as nonionic surfactant.

An attempt has been made to remove color from wastewater containing toxic eosin dye (anionic dye) by cloud point extraction (CPE) in batch mode using a nonionic surfactant, Triton X-100 (TX-100). Most of the dye molecules get solubilized in the coacervate phase leaving a color free dilute phase. The effects of the concentration of feed mixture, temperature and salt concentration on the concentration of both dye and surfactant in the coacervate phase and dilute phase have been studied after the complete separation of two phases. Experimental investigations have also been carried out for the recovery of surfactant from dilute phase applying solvent extraction (SE) in batch condition. It has been observed that 87.5-100 percent eosin removal is possible for the feed dye concentration of up to 200 ppm using 0.1(M) of TX-100 and 0.2(M) of salt (NaCl) at 80 degrees C. About 88 percent of TX-100 can be recovered from dilute phase using solvent extraction method. It is concluded that the cloud point extraction techniques for the dye removal may be an alternative to the present dye removal processes.