| H-acid is an important naphthalene dyes intermediates, and the wastewatercontaining H-acid exhibits high concentration of COD, strong acidity, high chromaticityand poor biodegradability, which is refractory to remove via traditional technology. Thepresent work investigated the treatment of H-acid by using Catalytic Wet Oxidationprocess with the γ-Al2O surpoted Mn-Ce-O composite catalyst. The related results willpave the way to the treatment of actual H-acid-containing wastewater by Catalytic WetOxidation process.Firstly, γ-Al2O3supported Mn-Ce-O (Mn/Ce molar ratio=7/3) composite catalyst isprepared by iso-volumetric wet impregnation. To optimize the preparation conditions, thepreparation factors of calcinations temperature, calcinations time, impregnationconcentration and dipping method, were investigated. Secondly, the simulated H-acidwastewater was treated in a Catalytic Wet Oxidation system by using the γ-Al2O3supported Mn-Ce-O composite catalyst. Results show that the optimal degradationcondition is the temperature of453K, pressure of2.83MPa, the initial pH of2.52and thecatalyst load of5g/l. Under this condition, the COD removal rate is86.15%with a40minreaction time. Result also indicates that Mn-Ce-O composite catalyst has a high activity,but the leaching of active ingredient Mn and the deposition of carbonaceous by-productscan lead the loss of activity. Thereby，we modified this catalyst by doping potassium andsilver, SEM, XRF and BET analysis showed that it improved the activity and stabilitysignificantly. The kinetics of the degradation of H-acid shows that it followed the firstorder reaction kinetics. By linear fitting the rate constants of different temperature，thereaction activation energy is determined as55.97kJ/mol without catalyst and41.38kJ/molwith Mn-Ce-O composite catalyst, respectively. Thereby, the Mn-Ce-O composite catalystis unfitble to the treatment of H-acid-containing wastewater by using Catalytic WetOxidation process. |
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