Catalytic Ozonation Of Dye Wastewater With Active Carbon Loaded Metallic Oxide

Traditional wastewater treatment methods, such as physical and chemistry method and biological process, can't work well, their effluent also contain high concentration refractory organics, making CODcr value and chroma out of limits. This study is to synergily degrad dye wastewater with ozone and AC loaded metal oxide, develop loaded catalyst with lower cost, make ozone catalytic reactor, and try middle-scale experiment.In the solo ozonation system, oganics were mainly removed by direct oxidation, the ozone concentration was 27.98 mg·L-1, reaction time was 25min. Although the oxidation efficiency was low, there are not any peak of other middle product on UV-VIS absorption has been found. Treating practical wastewater, the removal efficiency of chroma was a little, and COD of Matian acerbic dye was 22.3%, active dye of socks plant was 15.4%, Yuanxing disperse dye was 39.29%.In the catalytic ozonation system, catalysts of AC loaded with Fe,Mn,Fe-Mn and Fe-Ce were prepared with sedimental method, the best one was choosen. The target to obtain the optimal preparation and oxidation conditions were the removal efficiency of CODcr value and chroma. The results indicated that the removal efficiency of dye wastewater was high to 90% when the ozone concentration was 27.98 mg·L-1, reaction time was 12min, and the catalyst was prepared under 400℃and the mole ratio of Fe vs Mn was 1:1. Different dye wastewater has inequable disposing level, acerbic dye was easy to be oxided, then was the disperse dye.In the pilot-scale experimental system, the removal efficiency of CODcr of raw water and primary water of disperse dye were 67.1% and 55.1% when the concentration of ozone was 2.494 g-L"1 and the water was circularly treated 4 times using single pole. Using second-order pole to dispose primary water of disperse dye, the effect of catalytic ozonation was much better than solo ozonation, theirs removal efficiency of CODcr were 21.84% and 12.89%, and the retention time was 13 min. If the retention time was controlled at 50min, the COD can fall to 100. The cost of water treatment was 1.76 yuan·m-3.The spectrophotometry was used to determine probable radical during the reaction and fit kinetic equation. The results showed that the ptocess of ozonation disperse dye follow to mechanism of hydroxyl radical and second order reaction; While in the Fe-Mn/AC catalytic ozonation system, hydroxyl radical was not the main active species. Theirs degradation rate of disperse dye were 0.0371 L·mg-1·min-1 and 0.4027 min-1, the rate of catalytic ozonation was 10 times of solo ozonation.