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

• Non-thermal plasma technology was firstly applied to treat ibuprofen wastewater.
• Reaction order and kinetics of ibuprofen degradation are investigated.
• The byproducts are evaluated and possible pathway of IBP degradation is proposed.

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 × 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.