# Chlorobenzene Removal Using DBD Coupled with CuO/\(\gamma\)-Al\({}_{2}\)O\({}_{3}\) Catalyst
## 3 Results and Discussion
### Byproducts Analysis and Reaction Mechanism  
In this study, the byproducts of chlorobenzene degradation were analyzed by GC-MS and are summarized in Table 4. The aromatic organic compounds include C6H4 Cl2 and C6H4 ClNO2. The aliphatic organic compounds mainly contain carboxyl, ether, and halogenated groups, and the length of the carbon chain mainly concentrates between C2 and C4. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Response** & **Model Terms** & **Sum of Square** & **Degree of Freedom** & **Mean Square** & **F-Value** & \(p\)**-Value** \\ \hline Removal efficiency & Model & 3184.30 & 5 & 636.86 & 91.27 & \textless{}0.0001 \\ \hline  & x1 & 864.36 & 1 & 864.36 & 123.88 & \textless{}0.0001 \\ \hline  & x2 & 2112.32 & 1 & 2112.32 & 302.74 & \textless{}0.0001 \\ \hline  & x12 & 0.062 & 1 & 0.062 & 0.01 & 0.9266 \\ \hline  & x1x2 & 114.44 & 1 & 114.44 & 16.40 & 0.0019 \\ \hline  & x2 & 14.90 & 1 & 14.9 & 2.14 & 0.1719 \\ \hline  & Residual & 76.75 & 11 & 6.98 & & \\ \hline  & Total & 3261.05 & 16 & & & \\ \hline  & & \multicolumn{4}{c}{R2 = 0.9766, Adj R2 = 0.966, RMSE = 2.632, cv = 2.66\%} \\ \hline CO2 selectivity & Model & 198.39 & 5 & 39.68 & 30.16 & 0.0027 \\ \hline  & x1 & 76.18 & 1 & 19.04 & 14.47 & 0.0126 \\ \hline  & x2 & 109.83 & 1 & 109.83 & 83.49 & 0.0003 \\ \hline  & x12 & 1.58 & 1 & 1.58 & 1.20 & 0.3231 \\ \hline  & x1x2 & 2.72 & 1 & 2.72 & 2.07 & 0.2100 \\ \hline  & x2 & 2.58 & 1 & 2.58 & 1.96 & 0.2203 \\ \hline  & Residual & 14.47 & 11 & 1.32 & & \\ \hline Total & 212.86 & 16 & & & \\ \hline \hline  & \multicolumn{4}{c}{R2 = 0.9466, Adj R2 = 0.922, RMSE = 1.016, cv = 3.03\%} \\ \hline \end{tabular}
\end{table} 
Table 3: The magnitude and significance analysis of factor effects on the responses. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Name** & **Structure** & **DBD Reactor** & **DBD-Catalysis Reactor** \\ \hline \hline Oxalic acid & \(\begin{array}{c}\text{HO}\\ \text{OH}\end{array}\) & \(\begin{array}{c}\text{\surd}^{*}\\ \text{OH}\end{array}\) & \(\begin{array}{c}\text{\surd}^{*}\\ \text{OH}\end{array}\) & \(\begin{array}{c}\text{\surd}\\ \text{\surd}\end{array}\) & \(\begin{array}{c}\text{\surd}\\ \text{\surd}\end{array}\) \\ \hline Maleic acid & \(\begin{array}{c}\text{O}^{\text{OH}\text{HO}}\\ \text{O}\end{array}\) & \(\begin{array}{c}\text{\surd}\\ \text{\surd}\end{array}\) & \(\begin{array}{c}\text{\surd}\\ \text{\surd}\end{array}\) & \(\begin{array}{c}\text{\surd}\\ \text{\surd}\end{array}\) \\ \hline Benzene, 1,2 (or 1,3 or 1,4)-dichloro- & \(\begin{array}{c}\text{Cl}\\ \text{Cl}\end{array}\) & \(\begin{array}{c}\text{\surd}\\ \text{\surd}\end{array}\) & \(\begin{array}{c}\text{\surd}\\ \text{\surd}\end{array}\) & \(\begin{array}{c}\text{\surd}\\ \text{\surd}\end{array}\) \\ \hline \hline \end{tabular}
\begin{tabular}{c} Acetic Acid, Dichloro- \\ \hline \hline
2,5-Cyclohexadiene-1,4-dione, 2-chloro- \\ \hline Benzene, 1-chloro-3 (or 2 or 4)-nitro- \\ \hline
4-chloro-2-nitrop \\ \hline Phenol, 2,4-dichloro-6-nitro- \\ \hline Phenol,2,4-dichloro-6-nitro- \\ \hline Phenol,2,4-dichloro-6-nitro- \\ \hline Pryocatech, 3,4,6-trichloro- \\ \hline Benzene, 1,1\({}^{\prime}\)-oxybis [4-chloro- \\ \hline \hline \end{tabular}  
*: The detected byproducts were marked by “\(\text{\surd}^{\text{\surd}}\).  
\end{table} 
Table 4: Byproducts analysis results. In previous studies, [PERSON] et al. thought that the chlorinated aromatic organic compounds would undergo dechlorination first, and then the benzene ring would be opened under the attack of active particles [59]. When analyzing the degradation process of chlorobenzene, [PERSON], [PERSON] considered that OH- radical played an important role in the degradation process of chlorobenzene [60, 61]. [PERSON] et al.