Treatment of Paper-making Wastewater by Catalytic Wet Air Oxidation Method

Paper-making wastewater was treated by catalytic wet air oxidation method using CuO as active composite supported on γ-Al2O3.Effect of influencing factors on COD removal rate was investigated,including Cu loading,amount of catalyst and reaction temperature.Results showed that based on p(O2)2.5MPa and reaction time 3h,COD removal rate was 90% and pH value declined from 9.6 to 7.8 for 500mL paper-making wastewater with concentration of 3250mg/L when Cu loading was 4% ,amount of catalyst was 3g and reaction temperature was 220℃.Regeneration treatment of catalyst was carried out and its stability was determined.Results showed that COD removal rate decreased to 88% for raw wastewater at the same above reaction conditions when catalyst was calcinated for 3h at 450℃ .After the catalyst was used repeatedly for 9times,COD removal rate maintained 85%.