Shang Kefeng
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Indexed by:Journal Papers
Date of Publication:2019-01-01
Journal:SEPARATION AND PURIFICATION TECHNOLOGY
Included Journals:SCIE、EI
Document Type:J
Volume:218
Page Number:106-112
Abstract:Dielectric barrier discharge (DBD) plasma in situ generates reactive species (e*, [rad] OH, [rad] O, [rad] H, H 2 O 2 , O 3 , etc.), UV irradiation and local high temperature. These physiochemical effects can non-selectively destroy aqueous organic contaminants, but the energy efficiency of DBD plasma for water decontamination can be further improved. Persulfate (S 2 O 8 2- , PS) and ferrous ions (Fe 2+ ) were employed for enhancing the degradation of p-nitrophenol (PNP). An addition of both S 2 O 8 2- (<2.5 mM) and Fe 2+ (<36 µM) in PNP solution apparently promoted the degradation efficiency of PNP and energy efficiency compared to discharge plasma alone, due to a more production of active [rad] OH and SO 4 ·- through Fenton-like reactions and PS activation process. Moreover, the tertiary system of plasma/PS/Fe 2+ (81.1%) presented higher PNP degradation efficiency after 50 min treatment than discharge plasma alone (34.8%) and the binary systems of plasma/PS (63.6%), plasma/Fe 2+ (69.6%) and PS/Fe 2+ (13.7%). However, an excessive addition of S 2 O 8 2- (2.5–3.6 mM) and Fe 2+ (36–360 µM) had unobvious or even harmful influence on PNP degradation, possibly due to the enhanced recombination or consumption of [rad] OH and SO 4 ·- by radical side reactions. The effect of radical scavengers on PNP degradation indicates that [rad] OH was the most important radical species in plasma system for PNP degradation, but SO 4 ·- was also very important for PNP degradation when PS was present in solution. Besides Fe 2+ and the heat effect from discharge plasma, the electrons produced by electric discharge may also be one of the important contributors to the activation of PS. © 2019 Elsevier B.V.
