MgO/活性炭催化臭氧化降解有机物的作用机制 |
摘要点击 3134 全文点击 1201 投稿时间:2017-04-10 修订日期:2017-08-16 |
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中文关键词 臭氧 氧化镁 pH 草酸 敌草隆 稳定性 |
英文关键词 ozone magnesium oxide pH acetic acid diuron stability |
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中文摘要 |
利用浸渍法制备了MgO/活性炭(MgO/GAC-1)催化剂,研究了其在臭氧化降解敌草隆和乙酸中的活性,并与已有研究中沉淀法制备的MgO/活性炭(MgO/GAC-2)作了稳定性对比.结果表明,在降解敌草隆和乙酸的过程中,MgO/GAC-1能使臭氧化的效率提高约15%~35%.当溶液初始pH为中性或碱性时,MgO/GAC-1可以有效减缓由于形成小分子有机酸而导致pH的下降问题,从而保证臭氧的氧化效率.当溶液初始pH为酸性时,MgO/GAC-1在一定程度上可以提升溶液的pH值,进而提升臭氧化的效率.因此MgO对溶液pH值的调节作用可能是臭氧化效率提高的主要原因,这是相关文献所忽略的.尽管MgO/GAC-2有更大的比表面,但MgO/GAC-1却具有更好的催化臭氧化降解性能.在中性条件下降解乙酸重复10次实验的结果表明,MgO/GAC-1具有更好的稳定性,应用前景良好. |
英文摘要 |
MgO/granular activated carbon (MgO/GAC-1) was prepared via an impregnation method, and its activity in ozonation of diuron and acetic acid was investigated. MgO/GAC-1 was also compared in stability to the same catalyst prepared via precipitation according to the literature (MgO/GAC-2). The results showed that MgO/GAC-1 could increase efficiency of ozonation by 15%-35% in the process of degradation of diuron and acetic acid. When the pH of the solution was neutral or alkaline, MgO/GAC-1 could effectively retard the decrease in pH owing to formation of small molecular organic acids, thus ensuring the efficiency of ozone. When the pH of the solution was acidic, MgO/GAC-1 could increase the pH of the solution to a certain extent, thereby enhancing the efficiency of ozonation. The adjusting effect of pH value is the reason why MgO can significantly improve the efficiency of ozonation, a fact that was ignored in the relevant literature. Although MgO/GAC-1 had a larger specific surface area, MgO/GAC-1 had better activity in ozonation. A recycling test also indicated that MgO/GAC-1 had better stability, showing a good prospect for application. |
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