Jingren Yang,Deqian Zeng,Muhammad Hassan,Zhongbao Ma,Lingqian Dong,Yu Xie,Yiliang He
The discharge of recalcitrant and persistent organic pollutants into the environment and subsequent adverse impacts on the ecosystem has aroused a great concern all over the world. In this study, dielectric barrier discharge (DBD) non-thermal plasma was employed to eliminate bisphenol A (BPA). The influences of several vital experimental parameters, including discharge voltage, initial pH of solution, and rate of water flow on degradation of BPA, were explored in detail. In addition, the real wastewater from pharmaceutical factory was utilized to test the oxidation performance of DBD system. 96.8% chemical oxygen demand removal was achieved using DBD system. Radical quenching experiment as well as electron paramagnetic resonance test demonstrated that • OH was the main reactive oxygen species for the degradation of BPA. Moreover, eight major BPA degradation intermediates were identified by UPLC-MS. Ultimately, based on the UPLC-MS test results, a possible degradation pathway of BPA was proposed.
Nonthermal plasma has attracted extensive attention because of its ability to remove emerging organic micropollutants. However, its high amount of energy consumption severely limits its economic feasibility. In this study, sulfadiazine degradation was achieved in an optimized dielectric barrier discharge (DBD)-Contact system. The sulfadiazine removal in the DBD-Contact/peroxymonosulfate (PMS) system reached 91.8% within 15 min. Compared to a conventional DBD system, the energy efficiency (G 50 ) of the DBD-Contact/PMS system was 4.37 times greater, which meant a saving of 77.17% in electricity consumption. The reactive species generated by discharge plasma were identified as mostly excited nitrogen species in the gas phase, and after transferred to the water phase, OH and SO 4 − played an important role in the sulfadiazine removal. The hydroxylation of the S-N bond and the nucleophilic reaction of the pyrimidine ring were proposed as mechanisms for the sulfadiazine degradation, and the developmental and acute toxicity was significantly reduced after treatment. Furthermore, the DBD-Contact/PMS system showed good applicability in a wide pH range and complex practical water samples. This study finds that the DBD-Contact/PMS system can degrade antibiotics with high efficiency and low energy consumption and provides new insights for the practical application of DBD technology in water treatment.
Sisi Xiao,Zhou Shen,Shilin Song,Song Han,Yansheng Du,Huijuan Wang
Catalysis of the ZnO/cellulose acetate (CA) films in a multi-electrode paralleling dielectric barrier discharge (DBD) system for sulfadiazine (SDZ) degradation was investigated in this study. The catalysis was induced by the multiple physical and chemical effects produced during the DBD process. The obtained results on the reactive species formation revealed that the more O 3 , •OH as well as 1 O 2 could be formed by the addition of the ZnO/CA films into the DBD plasma system. The optimal additive conditions of the catalyst were 4 pieces of 3% the ZnO/CA films addition. There was a better catalytic effect of the ZnO/CA films than the equal amount of the nano ZnO powder addition. The ZnO/CA films still took on the catalytic activity after four cycles usage in the DBD plasma system. The possible degradation pathways were also speculated by analyzing the inorganic and organic intermediates formed during the SDZ degradation.
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