Journal of Chemical Engineering & Process Technology
Open Access

Abstract

Photodegradation study of Congo Red in Aqueous Solution using ZnO/ UV-A: Effect of pH And Band Gap of other Semiconductor Groups

Laouedj Nadjia, Elaziouti Abdelkader and Bekka Ahmed

The photocatalytic degradation of Congo red in aqueous solution was investigated under UVA light at different operating conditions, including irradiation time, pH solution and band gap of MO2 (M=Ti+4 and Ce+4) and M’2O3 (M’=Al+3 and Fe+3) semiconductor groups by UV-spectrophotometric monitoring. The results showed slight stability of 597nm band of CR over the pH range of 6-7, while, it almost completely disappeared at pH higher than 7. Maximum photo degradation was obtained at pH 8 as a result of 95.02% degradation efficiency of CR for 60 min of irradiation time. The photo decomposition efficiency of MO2 (M=Ti+4 and Ce+4) semiconductor group was higher, compared to that of M’2O3 (M’=Al+3 and Fe+3). Photodecomposition reactions correlated with pseudo-first-order kinetic model. These findings can support the design of remediation processes and also assist in predict their fate in the environment.