Abatement of chlorobenzene by plasma catalysis: Parameters optimization through response surface methodology (RSM), degradation mechanism and PCDD/Fs formation. (July 2022)

• Record Type: Journal Article
• Authors: Yu, Xin; Dang, Xiaoqing; Li, Shijie; Meng, Xiangkang; Hou, Hao; Wang, Pengyong; Wang, Qi
• Is Part Of: Chemosphere. Volume 298(2022)
• Publication Date: 2022-07
• Subjects: DBD-catalytic -- Chlorobenzene -- Response surface methodology -- Degradation mechanism -- PCDD/Fs; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.134274
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Dielectric barrier discharge coupled with 10 wt% Co/γ-Al2 O3 catalyst was developed to degrade chlorobenzene in this study. The effects of experimental parameters including applied voltage, flow rate, initial chlorobenzene concentration, and their interactions on the chlorobenzene degradation performance were investigated by the response surface methodology integrated with a central composite design. Results indicated that applied voltage was the most significant parameter affecting the mineralization rate and the concentration of ozone generated, while energy yield was mainly determined by initial chlorobenzene concentration. As a key precursor of polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs), polychlorophenols were found during the identification of the intermediates produced during chlorobenzene degradation through GC-MS. Furthermore, HRGC-HRMS was used to detect the remaining byproducts on the catalyst surface after 3 and 10 h discharge time, and three types of PCDD/Fs (2, 3, 7, 8-TCDF, 1, 2, 3, 4, 6, 7, 8-HCDF and OCDD) were detected after 10 h of discharge. The degradation mechanism of chlorobenzene was analyzed based on these detected intermediates, and the possible formation mechanisms of the three PCDD/Fs were proposed for the first time in plasma catalytic degradation of chlorobenzene. Graphical abstract: Image 1 Highlights: Applied voltage was the main factors affecting MR and the amount of export O3 . Initial CB concentration played a dominant role in energy yield. The possible degradation pathways of CB were proposed in DBD-catalytic system. PCDD/Fs formation mechanisms in NTP catalysis CB process was elucidated firstly.