Abstract: Benzene,toluene,ethylbenzene and xylene( BTEX) are typical refractory organic pollutants in coal chemical wastewater,which are usually difficult to be removed by traditional chemical oxidation technology.In this experiment,a porous ozone catalyst was prepared independently and the catalyst was characterized and analyzed.The best reaction conditions of degradation of BTEX by ozone catalytic oxidation were studied,and the excitation of free radicals in different reaction systems was compared.Based on this,the mechanism of the removal of BTEX by the ozone catalytic oxidation method was explored,which provided a theoretical basis for the technical application of BTEX in actual treatment process. The analysis results of XRD show that the porous ozone catalyst contains alumina and silica,and the catalyst contains compounds with a zeolite structure.XPS analysis results show that the synthesized catalyst contains Si,O,Cu,Fe,Mn,Al and other elements.The SEM results show that the catalyst is composed of many irregular small powders and its surface is very fluffy. The stacked multi-stage structure makes the catalystporous. The specific surface area analysis shows that the catalyst is porous with a specific surface area of 20.8 m~2/g,and the pore diameter is mainly concentrated at 3.8 nm.The experimental results of ozone-catalyzed oxidation of BTEX with this catalyst show that the degradation effect of BTEX is the best when the reaction temperature is 30 ℃,the solution pH is 8,the ozone dosage is 3.5 mg/L and the catalyst dosage is 5 g/L.In this reaction system,the removal rate of organic matter is 99.1%,and the removal rates of benzene,toluene,ethylbenzene and xylene are 95. 6%,98. 2%,100% and 100%,respectively. The ESR analysis results show that the excitation intensity of hydroxyl radicals and superoxide radicals in ozonation system is significantly higher than that in ozonation system. Because the catalysts prepared in this study contain Al,Fe,Mn and Cu oxides,which makes the valence states of supported metal oxides change each other during the catalytic reaction. The transferred electrons can promote the decomposition of ozone molecules,thus the more free radicals can be produced.Ozone catalytic oxidation is dominated by hydroxyl radicals,superoxide radicals and catalyst adsorption as a synergistic action to efficiently remove typical organic pollutants BTEX in coal chemical wastewater.