Extraction of Hexavalent Chromium from Wastewater Using Aliquat 336

Abstract

Removal of hexavalent chromium from aqueous waste solution by liquid– liquid extraction was studied using Aliquat 336 (tri-octal methylammoniumchloride) as an extractant (dissolved in kerosene) and decanol as a phase modifier. Extraction efficiency of the extractant was studied under different experimental conditions (extraction time, pH, effect of different acids, agitation speed, initial Cr (VI) concentration, and extractant concentration) in batch process. The results indicated that the extraction efficiency is much higher in acidic medium than that of basic medium. Maximum extraction took place in HCl medium among all the acids studied. The removal of Cr (VI) achieved within 30 min of extraction time at pH 1 was 99.78%. Agitation speed also showed a significant effect on the observed parameter. It was also observed that with the increase in the extractant concentration initial feed concentration decreased rapidly. Under the optimum experimental condition (pH-2, feed conc-50 ppm, extractant concentration-1 vol%), the percentage of extraction was achieved above 95%.