Latifoglu Aysegul, Gurol Mirat D
Environmental Engineering Department, Hacettepe University, Beytepe, Ankara 06532, Turkey.
Water Res. 2003 Apr;37(8):1879-89. doi: 10.1016/S0043-1354(02)00583-3.
Three types of commercially available humic acids from different sources were used to simulate natural organic matter in water for the investigation of nitrobenzene oxidation by ozonation and O(3)/UV. Despite the structural differences among the Fluka, Aldrich and Suwanee River humic acids as reflected by the UV absorptivity, their effects on nitrobenzene removal rate was observed to be similar for the two processes. Removal rate of nitrobenzene was hindered by the addition of humic acids in ozonation as well as in O(3)/UV processes. However, the hindrance by the humic acids was more pronounced in O(3)/UV as compared to the ozonation process. The effect of humic acid in O(3)/UV was primarily a UV light screening. Addition of humic acids above a certain concentration did not cause any further retardation on nitrobenzene removal rate by ozonation and O(3)/UV. Accumulation of hydrogen peroxide as well as probable formation of peroxy radicals in the solutions might induce chain promoting reactions to produce hydroxyl radical during the nitrobenzene oxidation. For waters containing high levels of humic acid, ozonation alone might be as effective as O(3)/UV process for the removal of nitrobenzene.
使用三种不同来源的市售腐殖酸来模拟水中的天然有机物，以研究臭氧化和O(3)/UV对硝基苯的氧化作用。尽管Fluka、Aldrich和苏万尼河腐殖酸之间的结构差异通过紫外吸光度反映出来，但观察到它们对这两种过程中硝基苯去除率的影响相似。在臭氧化以及O(3)/UV过程中，腐殖酸的添加会阻碍硝基苯的去除率。然而，与臭氧化过程相比，腐殖酸在O(3)/UV中的阻碍作用更为明显。腐殖酸在O(3)/UV中的作用主要是对紫外线的屏蔽。在一定浓度以上添加腐殖酸不会对臭氧化和O(3)/UV去除硝基苯的速率造成进一步的阻碍。在硝基苯氧化过程中，溶液中过氧化氢的积累以及可能形成的过氧自由基可能会引发链式促进反应以产生羟基自由基。对于含有高浓度腐殖酸的水，单独的臭氧化对于去除硝基苯可能与O(3)/UV过程一样有效。
