【作者】 方俊辉；

【导师】 荆国华；

【作者基本信息】 华侨大学 ， 环境工程， 2011， 硕士

【摘要】 染料因其应用的广泛性、降解产物的致癌性和较低的生物降解性,对人类健康和生态系统造成巨大威胁。本文以偶氮染料酸性红B和酸性大红GR为研究对象,考察了催化剂制备条件、反应条件对催化臭氧氧化的影响,探索了催化臭氧氧化染料废水的作用机理,得出以下结论:采用自蔓延法制备一系列金属氧化物催化剂,其中铁氧化物和铁铜复合氧化物对臭氧氧化具有较好的催化效果。与单独臭氧氧化相比,加入铁氧化物反应20min时酸性红B的去除率提高7%,而相同条件下加入铁铜氧化物去除率提高24%。60min时单独臭氧氧化COD去除率为48%,而加入铁氧化物和铁铜氧化物的去除率分别提高至60%和70%。由EDS和催化剂的重复性实验可知,催化剂具有良好的稳定性。由一系列实验结果可推测出铁铜复合氧化物催化臭氧氧化酸性红B的机理为:溶解性臭氧在催化剂表面羟基的催化下分解产生羟基自由基,羟基自由基和溶解性臭氧一起氧化溶液中和化学吸附在催化剂表面的酸性红B。主要降解中间产物为乙酸,由降解中间产物推导出酸性红B的降解途径,建立了酸性红B和COD的降解动力学模型,三个体系下酸性红B和COD的降解都符合拟一级动力学方程。采用浸渍法制备一系列氧化铝催化剂,其中Co/Al₂O₃和Ni-Co/Al₂O₃催化剂催化效果最好,催化剂的最佳制备条件为:Co负载量2%,搅拌时间4h,煅烧时间2h,煅烧温度500℃,Ni负载量2%。单独臭氧反应10min,酸性大红GR的去除率为54%,分别加入Co/Al₂O₃和Ni-Co/Al₂O₃后,去除率依次提高到69%和80%。单独臭氧氧化45min,COD去除率为28.6%,分别加入Co/Al₂O₃和Ni-Co/Al₂O₃后,COD去除率依次提高到59.4%和78.6%。由SEM、比表面积、EDS表征结果和催化剂的重复使用可知,催化剂具有良好的稳定性。由一系列实验结果可推测出Ni-Co/Al₂O₃催化臭氧氧化酸性大红GR的机理为:溶解性臭氧在表面羟基的催化下分解产生羟基自由基,羟基自由基和溶解性臭氧一起氧化溶液中和物理吸附在催化剂表面的酸性大红GR。推导出了酸性大红GR的降解途径,并建立酸性大红GR和COD的降解动力学模型,三个体系下酸性大红GR和COD的降解都符合拟一级动力学方程。更多还原

【Abstract】 Dyes induce a significant threat to human health and ecological systems due to their widespread use, carcinogenic characteristic of degradation byproducts and low biodegradability. This study used azo dyes Acid Red B and Acid scarlet GR as the research objects, investigated the influence of preparation and reaction conditions on catalytic ozonation of Acid Red B and Acid scarlet GR, and explored the catalyzing mechanism. The main results are as follows:A series of metal oxide catalysts were prepared by nitrate-citrate combustion route, the iron and Fe-Cu oxide had better catalytic effect on ozone oxidation. When adding iron and Fe-Cu oxide for 20 min, the removal rate of acid red B increased by 7% and 24%, which compared with ozone alone. After 60 min reation, the COD removal rate of adding iron and Fe-Cu oxide were 60% and 70%, while ozone alone was 48%. The results of EDS and catalyst repeated experiment showed that the catalyst had good stability. It is suggested that the catalyzing mechanism of catalytic ozonation of Acid Red B by Fe-Cu mixed oxide were: dissolved ozone were decomposed to hydroxyl radicals by the catalyst surface hydroxyl groups, and then hydroxyl radicals and dissolved ozone oxidated Acid Red B which in solution or chemical adsorption on the catalyst surface. The main degradation intermediate product of Acid Red B was acetic acid. The degradation pathway of acid red B was deduced, and the kinetics model of acid red B and COD degradation were established. In three systems, the degradation of acid red B and COD met pseudo first-order kinetics equation. A series of alumina catalysts were prepared by impregnating method, the Co/Al₂O₃ and Ni-Co/Al₂O₃ had better catalytic effect. The best preparation conditions of catalysts were: 2% of Co loading, Stirring for 4h, calcination for 2h, calcination temperature was 500℃, 2% of Ni loading. After 10 min reation, the Acid Scarlet GR removal rate of adding Co/Al₂O₃ and Ni-Co/Al₂O₃ were 69% and 80%, while ozone alone was 54%. After 45 min reation, the COD removal rate of adding Co/Al₂O₃ and Ni-Co/Al₂O₃ were 59.4% and 78.6%, while ozone alone was 28.6%. The results of EDS, surface area, SEM and catalyst repeated experiment showed that the catalyst had good stability. It is deduced that the catalyzing mechanism of catalytic ozonation of Acid Scarlet GR with Ni-Co/Al₂O₃ were: dissolved ozone were decomposed to hydroxyl radicals by the catalyst surface hydroxyl groups, and then hydroxyl radicals and dissolved ozone oxidated Acid Scarlet GR which in solution and physical adsorption on the catalyst surface. The degradation pathway of Acid Scarlet GR was deduced, and the kinetics model of Acid Scarlet GR and COD degradation were established. In three systems, the degradation of Acid Scarlet GR and COD met pseudo first-order kinetics equation.更多还原