Kinetics of Fe(3)O(4)-CoO/Al(2)O(3) catalytic ozonation of the herbicide 2-(2,4-dichlorophenoxy) propionic acid.
Kinetics of Fe(3)O(4)-CoO/Al(2)O(3) catalytic ozonation of the herbicide 2-(2,4-dichlorophenoxy) propionic acid.
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DOI：
10.1016/j.jhazmat.2010.09.013
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发表时间：
2011-01
影响因子：
13.6
通讯作者：
S. Tong;Rui Shi;Hua Zhang;Chun-an Ma
中科院分区：
文献类型：
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作者：
S. Tong;Rui Shi;Hua Zhang;Chun-an Ma
Fe 3 O 4-CoO/Al 2 O3催化剂的存在可显著提高臭氧氧化降解除草剂2-（2，4-二氯苯氧基）丙酸（2，4-DP）的效率。考察了pH值、催化剂浓度和清除剂添加量等因素对降解效率的影响。并对催化臭氧化反应动力学进行了讨论。结果表明，在Fe 3 O 4-CoO/Al 2 O3催化臭氧化2，4-DP过程中，2，4-DP吸附后的氧化和羟基自由基（OH）的氧化是导致臭氧化效率显著提高的两个因素，其中OH的氧化起着重要作用。在控制条件下，O3和O3/Fe 3 O 4-CoO/Al 2 O3降解2，4-DP的表观反应速率常数分别为2.567×10−4s− 1和1.840×10−3s− 1。采用相对法进行反应动力学分析的结果表明，O3/Fe 3 O 4-CoO/Al 2 O3具有比O3更大的Rct（Rct定义为OH暴露与O3暴露的比值，[公式：见正文]），表明O3/Fe 3 O 4-CoO/Al 2 O3产生更多的羟基自由基。
The presence of Fe3O4–CoO/Al2O3can improve degradation efficiency significantly during the ozonation of the herbicide 2-(2,4-dichlorophenoxy) propionic acid (2,4-DP). The main factors affecting degradation efficiency, such as pH, the catalyst concentration and addition of the scavenger, were investigated. The kinetics of the catalytic ozonation are also discussed. The results indicate that two factors, the oxidation after adsorption of 2,4-DP and the oxidation of hydroxyl radicals (OH), lead to a great enhancement in ozonation efficiency during the catalytic ozonation of 2,4-DP in the presence of Fe3O4–CoO/Al2O3, in which the oxidation of the OH plays an important role. Under controlled conditions, the apparent reaction rate constants for the degradation of 2,4-DP were determined to be 2.567×10−4s−1for O3and 1.840×10−3s−1for O3/Fe3O4–CoO/Al2O3. The results from the analysis of the reaction kinetics using the relative method showed that O3/Fe3O4–CoO/Al2O3possessed a larger Rct(Rctis defined as the ratio of the OH exposure to the O3exposure, [Formula: see text] ) than O3, indicating that O3/Fe3O4–CoO/Al2O3produced more hydroxyl radicals.