Study On The Treatment Of Aniline Wastewater By Electro-Heterogeneous Catalysis Coupling Reactor

The three-dimensional electrode electrochemical technology used in the environmental pollution controlling has attracted much attention recently and it is widely used for the treatment of organic wastewater, but its current efficiency is still low. In this paper, the multi-phase catalysis technology was introduced into the electrochemical reactor. With a combination of electrochemical and multi-phase catalysis technologies, the degradation efficiency and the current efficiency of the reactor were improved.Under batch conditions, CuO-γ-Al₂O₃, Fe₂O₃-γ-Al₂O₃, Fe₂O₃-13X zeolite were used as insulated fillings, respectively to treat the simulated aniline wastewater(COD, 800mg/L). The construction and components of multiphase catalysts were indicated and the degradation mechanism of aniline was also discussed preliminarily. The results show that the removal effects of COD by reactors with different insulated fillings are all obvious. Under the optimal conditions(electrolysis time of 1h, applied cell voltage of 30V, initial pH value of 7.3 and electrolyte concentration of 800mg/L), the COD removal efficiency for three reactors are 36.53%, 30.36% and 29.54% respectively. By comparison of different reactors under the optimal conditions, it is believed that catalysts supported on insulated fillings improve the removal efficiency greatly. It is demonstrated that γ-Al₂O₃ is a much better carrier when Fe₂O₃ is used as the active content. It is observed that the COD removal efficiency of different insulated fillings has the following descending sequence: CUO-γ-Al₂O₃> Fe₂O₃-γ-Al₂O₃ > Fe₂O₃-13X zeolite > γ-Al₂O₃ > 13X zeolite > quartz sand. By energy balance calculation, it is concluded that the electrochemical energy consumption of electro-heterogeneous catalysis reactors is reduces greatly and the current efficiency is improved obviously.Under normal temperature and pressure, when CUO-γ-Al₂O₃ was investigated to treat the aniline wastewater, it is observed that the optimal preparation conditions are active metal content of 5%, soaking time of 24h, roasting temperature of 500℃, roasting time of 5h, with removal efficiency of aniline is 87.28%.CUO-γ-Al₂O₃ catalyst prepared under the optimal conditions was used in the circulative batch electro-heterogeneous catalysis system. The effects of various influence factors such as flow rate, applied cell voltage and initial concentration of aniline were investigated in detail.The degradation of aniline is accorded with the pseudo 1st order kinetics and the apparent rate constants are presented.