Efficient Oxidative Degradation Of 2,4-dichlorophenol Over Supported CuO-based Catalysts

2,4-Dichlorophenol, one of foul, unusual smell, toxic and hardly biodegraded organic pollutants, is widely used in chemical industy, pharmacy, dye, paper making, disinfectant and preservative agents, etc. and entry surface water to pollute the environment by the means of industrial wastewater. Besides chlorophenols have neurotoxicity, induction of organ and carcinogenicity, which has greatly harm. So how to reduce the environment pollution of chlorophenols have received high-level attention.In recent years, the catalytic oxidative degradation of chlorophenols, one of the effective and economical treatment technologies, has been given comprehensive attention by the scientific community and projiect dominating. In this paper, the catalytic oxidative degradation of 2,4-DCP was investigated and the catalysts were characterized by XRD and NH3-TPD techniques. The results indicated that CuO/γ-Al₂O₃ exhibited high degradation activity among the metal oxide catalysts and supported catalysts. 2,4-DCP could be completely converted and the liberation of the inorganic chloride improved remarkably by adding alkaline metal oxides or alkaline-earth metal oxides into CuO/γ-Al₂O₃ catalyst after 2 h of reaction at 30℃. Supported CuO catalysts with good dispersion of CuO particles and fewer amounts of acid sites took advantage of the oxidative degradation of 2, 4-DCP. Some parameters, such as H₂O₂ dose,the active component CuO loading,reaction temperature, pH of the initial 2,4-DCP solution, reaction time, etc, were investigated. The results indicated that the CuO loading of 0.9 mmol/g was the best choice for CuO/γ-Al₂O₃ catalyst; the least dosage of hydrogen peroxide is 1ml; the liberation of the inorganic chloride of of 2,4-DCP increased with the reaction temperature; the dechlorination reaction was promoted under the alkaline condition and initial pH of 11 was preferred for the oxidative degradation of 2,4-DCP over the CuO/γ-Al₂O₃ catalyst; under the optimum reaction conditions, the liberation of the inorganic chloride of of 2,4-DCP could reach 100% over the CuO supportedγ-Al₂O₃ catalyst with the active component loading of 0.9 mmol/g in the presence of an environmentally clean oxidant of hydrogen peroxide at initial pH of 11 after 24 h of reaction at 30℃. A probable degradation pathway for 2,4-DCP was proposed.