Research On Preparation And Property Of Catalyst Used In Catalytic Wet Oxcidation Process Under Normal Temperature And Atmospheric Pressure

Dying wastewater is difficult to treat by traditional processes. In Catalytic wet oxidation (CWO) process,·OH could be produced by introducing catalysts and oxidant, which has strong oxidation capability that the pollutant can be degraded effectively. So CWO has great potential in dying wastewater treatment. Compared with traditional wet air oxidation (WAO), CWO makes operating condition gentler. But it still runs under certain temperature and pressure. Catalyst is the key techniques in CWO process. In this paper, Fe2O3-CeO2-TiO2/γ-Al2O3 catalyst was prepared by consecutive impregnation method and characterized by BET, XRD, SEM, XPS and XRF methods. The catalytic activity of prepared catalyst was evaluated by using three azo dyes methyl orange (MO),acid orange (AO), and reactive black (RB) as model pollutants in both catalytic wet peroxide oxidation (CWPO) and catalytic wet air oxidation (CWAO) processes. The deactivation and regeneration of Fe₂O₃-CeO₂-TiO₂/γ-Al₂O₃ catalyst were also investigated.The prepared parameters were optimized and the results showed that the catalyst with 1% titanium doping content and calcined at 450℃for 2 hours has the highest catalytic activity. The BET, XRD, SEM, XPS and XRF tests indicated doping titanium can increase the surface area and total pore volume of the catalyst as well as promote the dispersion of active component Fe on the surface. It can also prevent Ce from dissolving. The active test showed in normal temperature and atmospheric pressure, the color removal of MO, AO and RB could be 98.09%, 93.17% and 64.25% within 150 minutes respectively. Meanwhile, the removal of COD and TOC was also satisfied.The kinetics of degradation of AO (the concentration of dye is 500mg/L) by CWAO and CWPO pocesses in normal temperature and atmospheric pressure were investigated. By the kinetic equations established, it was known that the active energy in CWPO and CWAO systems are 20.64 KJ/mol and 17.32 KJ/mol, respectively, and their reaction rate constant are 1.0923 and 4.5053 respectively. It can be obviously seen that the dye degradable rate in CWAO process is higher than that in CWPO process under the studied condition.