# Chlorobenzene Removal Using DBD Coupled with CuO/\(\gamma\)-Al\({}_{2}\)O\({}_{3}\) Catalyst
## 4 Conclusions  
Compared with the single DBD reactor and the DBD reactor coupled with Al\({}_{2}\)O\({}_{3}\), the DBD reactor coupled with CuO/\(\gamma\)-Al\({}_{2}\)O\({}_{3}\) catalyst demonstrated better chlorobenzene degradation and complete oxidation ability. The DBD reactor coupled with CuO/\(\gamma\)-Al\({}_{2}\)O\({}_{3}\) catalyst can effectively degrade chlorobenzene into CO\({}_{2}\) through the oxidation of intermediates, especially under low voltage conditions. With the increase in energy density, the intermediates of chlorobenzene degradation start to accumulate, and the promotion effect of catalyst is gradually weakened. In addition, the impacts of discharge power and flow rate on the degradation of chlorobenzene were investigated using the RSM method. The  
Figure 11: A speculative decomposition mechanism of chlorobenzene by DBD. *: The R - refers to the free radicals generated by the DBD discharge.  
regression correction (R\({}^{2}\)) coefficients obtained indicates that the regression model fits the experimental results well. The analysis of variance also supports the conclusion that the interactions between flow rate and discharge power for chlorobenzene removal are not trivial. Moreover, based on the analysis of byproducts, chlorobenzene may combine with OH, O, and other free radicals to form 4-chlorophenol under the attack of high-energy electrons. The latter will be broken into unsaturated hydrocarbons with four or two carbon atoms after further oxidation and ring-opening. These unsaturated hydrocarbons can be fully oxidized under the attack of free radicals such as OH- and O. Although the combination of DBD with CuO/\(\gamma\)-Al\({}_{2}\)O\({}_{3}\) catalyst has many advantages, it may lead to the formation of extra polychlorinated compounds.  
Conceptualization, X.J., G.W.; Data curation, X.J.; Formal analysis, X.J. and R.Z. ([PERSON]); Funding acquisition, G.W. and S.C.; Investigation, X.J.; Methodology, [PERSON] ([PERSON]) and G.W.; Project administration, [PERSON] ([PERSON]); Resources, S.C. and J.H.; Supervision, [PERSON] ([PERSON]) and W.Z.; Validation, L.L. and W.Z.; Visualization, X.J. and F.G.; Writing--original draft, X.J.; Writing--review and editing, X.J. and R.Z. ([PERSON]). All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China (no. 21577023), the technology innovation and level promotion project supported by Shanghai State-owned assets supervision and Administration Commission (no. 2018001) and the science and technology innovation action project supported by the Science and Technology Commission of Shanghai Municipality (no. 18 DZ1202605) and Natural Science Foundations of Hainan Province (no. 219 QN290).  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to at this time as the data also forms part of an ongoing study.  
The authors thank [PERSON] for his help in the research work.  
The authors declare no conflict of interest.