Photocatalytic hydrogen driven (Pd-C\UV\H2) advanced reduction process (ARP) for dechlorination and degradation of chlorotoluron in aqueous environment

This paper present a novel investigation of the dechlorination and degradation of chlorotoluron (CHL) a persistent phenylurea herbicide type contaminant by the highly effective advanced reduction process (ARP), based on photocatalytic activation of hydrogen gas (H 2 ) by UV light and palladium on activated carbon (Pd-C) catalyst under aqueous conditions. Importantly, developed system is based on entirely new degradation mechanism which is much more effective comparing to typical UV-based or catalytic hydrogenation processes. The developed process is dedicated to wastewater treatment applications. This approach achieved >99.4% CHL reduction and >94.1% dechlorination at ambient temperature within 10 min. The degradation process followed a pseudo first order kinetics with k obs of 0.1196 min −1 . Studies on degradation mechanism revealed contribution of generated hydrogen radicals (H • ) and auxiliary role of hydrated electrons (e aq – ). The reaction system was found to be very effective also in presence of inorganic anions. Performed studies proved stability of the performance over 5 cycles using same batch of catalyst. This part of the studies confirmed full applicability of the method for industrial practice. Operational costs of the treatment were estimated around 31.42$/m 3 .