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研究报告

李能能,聂玉伦,胡春.Fe-Al/Al₂O₃催化臭氧化去除水中有机污染物2,4-D过程中溴酸盐的生成控制研究[J].环境科学学报,2013,33(7):1849-1854

Inhibition of bromate formation during catalytic ozonation of organic pollutant 2,4-D in bromide-containing water over Fe-Al/Al₂O₃

摘要：采用浸渍、强化水解和后续水浴加热的方法制得催化剂Fe-Al/Al₂O₃,并通过XRD和XPS等表征手段对其结构性能进行了研究.结果表明,催化剂中铁是以二价和三价存在,且以三价铁为主;铝则以Al₂O₃和AlOOH形态存在.与单独臭氧化相比,Fe-Al/Al₂O₃既能高效矿化水中的难降解有机物2,4-二氯苯氧乙酸(2,4-D),又能明显抑制溴酸盐的生成,体现出很好的循环使用稳定性.进一步探讨了臭氧投加量和溴离子初始浓度对催化臭氧化效率和溴酸盐生成的影响.研究表明,在Fe-Al/Al₂O₃催化臭氧化过程中,水中溴酸盐浓度受臭氧投加量和溴离子初始浓度的影响较小,均可明显抑制溴酸盐的生成,且有机物的矿化效率随着臭氧投加量的增加而显著提高.

Abstract：Fe-Al supported on γ-Al₂O₃ (Fe-Al/Al₂O₃) was prepared via impregnation method followed by hydrolysis and hydrothermal treatment. Based on characterization of X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), Fe³⁺ and Fe²⁺ coexisted in Fe-Al/Al₂O₃ while Al was in the state of Al₂O₃ and AlOOH. In comparison with ozonation alone, the addition of Fe-Al/Al₂O₃ resulted in complete inhibition of BrO₃^- formation with higher efficiency for catalytic ozonation of 2,4-dichlorophenoxyacetic acid (2,4-D). Moreover, the catalyst could be reused for six times without significant loss of activity, indicating Fe-Al/Al₂O₃ has an excellent long-term stability. The effects of ozone dose and bromide concentration on TOC removal and bromate formation were also studied. The results showed that no significant bromate formation was found in catalytic ozonation process over Fe-Al/Al₂O₃ even with the increased ozone dose and bromide concentration, whereas the increase of ozone dose could result in higher TOC removal efficiency.