Photodegradation of Congo Red Dye Via Simple and Effective Air Oxidation Using Copper(II) Chloride and Sunlight

摘要

This paper reports the study of photodegradation of Congo red dye which is a major pollutant in dyeing industry using copper(II) chloride dihydrate as a catalyst. The rate of degradation is improved by direct supply of air instead of using other strong oxidants. The effects of other parameters such as pH, catalyst dosage, initial dye concentration and irradiation time were studied. It was found that over 100% of the dye removal can be effectively achieved within 90 minutes of air oxidation at pH 11 and a catalyst dosage of 0.4g/L. The kinetics on the rate of degradation of the dye has also been examined by using UV-Visible spectroscopic technique. Air oxidation of Congo red dye using CuCl 2 .2H 2 O was found to obey pseudo-first-order kinetics with respect to the substrate concentration. The study suggests the use of homogeneous CuCl 2 .2H 2 O catalyst for the photodegradation of dyes of reactive azo dye category. Future studies on the use of catalytic activity of CuCl 2 .2H 2 O for industrial effluents containing azo dyes as a major pollutant can be affected.