Degradation of pharmaceutical contaminant ibuprofen in aqueous solution by cylindrical wetted-wall corona discharge

Non-thermal plasma in cylindrical wetted-wall reactor was used to evaluate the degradation feasibility of non-steroidal anti-inflammatory drug ibuprofen (IBP) in aqueous solution and the corresponding kinetics were investigated. The influences of initial concentration and pulse repetition rate were studied. After 80 min plasma treatment, 91.7% removal of IBP was achieved and the degradation yield was 6.9 g/kW h for the initial concentration of 60 mg/l. The decomposition of IBP was in accordance with the first order reaction and the rate constant was 30.3 x 10(-3) min(-1). Degradation byproducts during plasma treatment were obtained by HPLC-MS and the possible degradation pathway was proposed. The total organic carbon (TOC) in the residual solution remained high although IBP was almost completely degraded. However, the high biodegradable index (BOD5/COD) indicated that it can be further degraded by the biological treatment. (C) 2015 Elsevier B.V. All rights reserved.