Liquid—Liquid Extraction of Chromium(VI) with Tricaprylmethylammonium Chloride Using Isoamylalcohol as the Diluent and Its Application to Industrial Effluents

摘要

A simple liquid—liquid extraction (LLE) method has been developed for the separation and determination of chromium in industrial wastewater. The Cr(VI) is held by electrostatic attraction as an ion-association complex of HCrO_4~- with tricaprylmethylammonium chloride and extracted into the organic phase using isoamylalcohol (IAA) as the diluent. The extract was clear without any third-phase formation. The effects of various experimental parameters that affect the extraction process have been examined in detail. The organic phase containing the metal extractant could be regenerated using ascorbic acid as the reducing agent. The organic phases were characterized with Fourier transform infrared (FT-IR) studies. The method was applied to the extraction of chromium from synthetic effluents, real wastewater samples, and a certified reference material.