Radiolysis of cardiovascular drug atenolol in aqueous solution by electron beam: Effect of water components and persulfate addition

Abstract

Atenolol (ATE) is one of the most frequently detected persistent emerging pollutants in wastewater. The performance of electron beam irradiation (EB) in decomposition and mineralization of ATE in aqueous solutions was evaluated. The results showed the radiolytic degradation of ATE was efficient with a degradation rate of 97% for 100 mg L−1 under 5 kGy. The degradation kinetic nicely followed pseudo first-order kinetic model. The effect of saturated solutions of N2O, O2, N2, and tert-butanol were studied, which elucidated that •OH played a major role and •H and e−aq played a minor role in ATE degradation. The presence of NO2−, NO3−, CO32−, Cl− and fulvic acid significantly affected the degradation of ATE. The degradation of ATE was seriously inhibited in municipal wastewater compared with surface water and ultrapure water. The TOC removal efficiency of ATE by electron beam alone was relative low about 3% in 10 kGy, which was improved to 20% combining with 10 mM K2S2O8 due to reaction between SO4•− radical and intermediates. The main radiolytic degradation pathways of ATE involved breakage of the ether bond in branched chain, cleavage of the isopropyl group and the carboxamide group, and attack to the aromatic ring by •OH radical. The potential active sites probed by Fukui function and Dual descriptor were consistent with the results of intermediates. This study envisaged a promising strategy to treat wastewater containing recalcitrant contaminants.