Heterogeneous Catalytic Wet Air Oxidation For The Treatment Of Phenol Wastewater

In this research program we added Ce and La as promoter to MnO2/γ-Al2O3 and made Mn, Ce and La compound catalysts, and we uses phenol simulation wastewater as catalytic wet air oxidation target. The new catalysts MnO2–CeO2–La2O3/γ-Al2O3 shows a good effect on CODCr removing. The catalyst preparation method is impregnation and we adopted commercialγ-Al2O3 balls as supporter. SEM and XRD were used to explain the good effect of catalyst which has a good CODCr removal rate to our target simulation wastewater. At the same time we discussed the optimum preparation conditions for catalyst. At the last, the working conditions including influent pH, stirring rate and catalyst dosage were taken into consideration to get a optimum working conditions when use the CWAO process. We especially discussed the influence of influent pH to the CODCr removal rate of CWAO reaction.The effect of promoter addition on activity of MnO2/γ-Al2O3 was assessed via the CWAO of phenol. MnO2/γ-Al2O3, MnO2–CeO2/γ-Al2O3, MnO2–La2O3/γ-Al2O3 and MnO2–CeO2–La2O3/γ-Al2O3 catalysts, prepared by impregnation ofγ-Al2O3 with aqueous solution containing Mn, La and Ce were used to study the influence of CeO2 and La2O3 on the structure and activity of MnO2/γ-Al2O3 catalyst in catalytic wet air oxidation (CWAO) of phenol. The surface properties of these catalysts were measured by XRD. A better dispersion of Mn particles was detected in the presence of CeO2 and La2O3 before the impregnation of MnO2/γ-Al2O3 catalyst. The experiment results show that the addition of CeO2 and La2O3 affects the chemical state of Mn and O elements and promotes the increase of the chemisorbed oxygen contents on the catalyst surface. Moreover, the removal of phenol with MnO2–CeO2–La2O3/γ-Al2O3 catalyst is more complete than with MnO2/γ-Al2O3, MnO2–CeO2/γ-Al2O3 and MnO2–La2O3/γ-Al2O3 catalyst.