Treatment Nitro Aromatics Wastewater By Bipolar Electro-Heterogeneous Catalysis Reactor

Electrochemical technology which has many advantages in treating organic wastewater will be widely applied in future. In this paper, the optimization of active component of catalyst which filled in electro-heterogeneous catalysis reactor was carried out in the heterogeneous catalysis reactor for the mechanism of H₂O₂ catalytic system in the heterogeneous catalysis reactor the same as that in the electro-heterogeneous catalysis reactor. The optimized catalyst with the best catalysis performance and stability was selected as insulated filling, the bipolar electro-heterogeneous catalysis reactor was constructed to treat the simulated p-nitrophenol wastewater and nitrobenzene wastewater.Using γ-Al₂O₃, 13X zeolite, NaY zeolite and slag as insulated filling, the removal efficiency of p-nitrophenol by heterogeneous catalysis reactor was studied. As well as the best active component and the optimal condition of different catalysts were also investigated. By comparison, CuO/γ-Al₂O₃ is the best catalyst and it is signed by the SEM and XRD methods. The optimal preparation conditions of CuO/γ-Al₂O₃ and the operating conditions of the reactor were also studied. The results show that the removal efficiency of p-nitrophenol under the optimal condition is above 85%.Because the dissolvation of carrier may result in the increase of pH value and conductivity of dipping solution, the enhancement of Fe³⁺ hydrolyzing affects the activity of catalyst. Using ethanol instead of deionizing water as the solvent of dipping solution, the removal efficiency of p-nitrophenol is increased from 55.2% to 58.1% and the catalyst demonstrates good stability after nine rounds of operation..Under batch conditions, various catalysts were used as insulated fillings, to treat the simulated p-nitrophenol wastewater, respectively. The operating conditions were optimized and the degradation mechanism of p-nitrophenol was also discussed preliminarily. It is shown that under the optimal conditions(electrolysis time of 1 h, applied cell voltage of 30 V, initial pH value of 5.2 and electrolyte concentration of 1000 mg/L), the p-nitrophenol removal efficiency of different insulated fillings has the following descending sequence: CiO-γ-Al₂O₃ >Fe₂O₃-slag> slag >Fe₂O₃-γ-Al₂O₃> quartz sand>γ-Al₂O₃. The p-nitrophenol removal efficiency of the CuO-γ-Al₂O₃ reactors is 78.7%. By comparison of different reactors under the optimal conditions, it is believed that the p-nitrophenol removal efficiency of reactor of slag unsupported catalyst is 66.5%. By energy balance calculation, it is concluded that the...