Insights into water film DBD plasma driven by pulse power for ibuprofen elimination in water: performance, mechanism and degradation route

Abstract

• IBP elimination using water film DBD plasma by pulse power was investigated. • The impact of various parameters on IBP elimination was inspected. • OH, electron, 1 O 2 and · O 2 – participation in IBP decomposition. • The degradation route was proposed based on DFT calculation and LC-MS. • The toxicity of actual wastewater alleviated after water film DBD treatment. Development of efficient abatement technology for drugs and personal care products (PPCPs) has important scientific and practical significance to restrain its discharge to the natural water environment. This research aims to investigate ibuprofen (IBP) elimination in water film dielectric barrier discharge (DBD) plasma system driven by pulse power. With raising input power, the removal rate was improved. When input was 95 W, the removal rate and kinetic constant were up to 96.1% and 0.090 min −1 , respectively. Besides, heightening frequency, duty ratio and solution flowrate would promote the degradation of IBP. IBP were more favorably degraded at lower IBP concentration and neutral pH condition. Active species including ·OH, electron, 1 O 2 and · O 2 – dominated decomposition of IBP. The generation of O 3 , · OH and H 2 O 2 in deionized water and IBP solution was compared. UV–Vis spectrum and three dimensional fluorescence spectroscopy illustrated that IBP molecules could be decomposed effectively after DBD plasma treatment. During IBP degradation, COD and TOC was also relieved with extension of treatment time. The possible degradation routes of IBP in water film DBD plasma system were proposed based on LC-MS and Discrete Fourier transform (DFT) simulation. Based on the identified intermediates, their potential toxicity was evaluated with the help of US-EPA-TEST software. Water film DBD plasma technology was also suitable for actual wastewater treatment. The comparison of other technologies for IBP degradation was carried out finally. This work can provide exploratory platforms for comprehensively understanding and enhancing IBP degradation in DBD plasma technology.