Distribution of Chromium Species and Physico-Chemical Analysis of Various Industrial Effluents in Hyderabad and Jamshoro, Pakistan

Abstract

This research aimed to quantify the speciation of chromium in different industrial effluent samples of Hyderabad and Jamshoro, Pakistan. The hexavalent chromium (Cr(VI)) was determined by microsample injection system flame atomic absorption spectroscopy (MIS-FAAS). The total chromium was measured by MIS-FAAS after the oxidation of trivalent chromium (Cr(III)) to hexavalent chromium (Cr(VI)) by Ce(SO4)2 in an acidic medium (0.07 M H2SO4). The content of Cr(III) was measured by the difference method (total chromium – hexavalent chromium). In the effluent samples of textile and fabrics industries, the total Cr was observed 400 to 1600 times higher than the US-EPA and WHO regulatory limit (0.10 mg/L) in the industrial discharge. In the effluent of food and plastic industries, the Cr(VI) was found to be high as compared to the Cr(III), and the Cr(III) was observed high in the effluent samples of chemical as well as textile and fabrics industries. The Cr(VI) was higher than the US-EPA and WHO regulatory limit (0.05 mg/L) in the effluent samples of all selected industries, but the Cr(III) was within the US-EPA and WHO regulatory limit (170 mg/L) in the industrial discharges.