Hydroxyl radical production via the photo-Fenton reaction in the presence of fulvic acid
Hydroxyl radical production via the photo-Fenton reaction in the presence of fulvic acid
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DOI：
10.1021/es020757l
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发表时间：
2003-03-15
影响因子：
11.4
通讯作者：
Voelker, BM
中科院分区：
文献类型：
--
作者：
Southworth, BA;Voelker, BM
光芬顿反应，光产生的Fenton与H2 O2反应以形成高活性羟基自由基（OH），可能是OH的重要来源。在阳光照射的自然沃茨。为了确定光芬顿反应是否在温和酸性表面沃茨中是显著的，我们使用标准富里酸和无定形氧化铁在pH 6.0下的溶液进行了模拟代表天然新鲜沃茨的条件的实验。一种测量由C-14标记的甲酸盐与OH反应产生的（CO2）-C-14的探针方法。用于检测小OH。生产率，而不会影响实验中发生的化学反应。同时使用吖啶酯化学发光法测定净H2 O2积累。通过在黑暗实验中与Fe（II）反应测得的H2 O2损失产生了大约预期量的OH。在富里酸溶液中暴露于光的Fe（III）的存在和不存在下的H2 O2积累之间的差异被解释为通过与光产生的Fe（II）反应的H2 O2的损失，与测量的OH一致。生产率。Fe配体甲磺酸去铁胺消除了两个OH。Fe引起的H2 O2产生和光损失。我们的研究结果表明，当Fe是H2 O2的主要汇时，光Fenton反应可能是OH的最重要来源。导致有机化合物在各种阳光照射的淡水中大量下沉。
The photo-Fenton reaction, the reaction of photoproduced Fell) with H2O2 to form the highly reactive hydroxyl radical (OH.), could be an important source of OH. in sunlit natural waters. To determine if the photo-Fenton reaction is significant in mildly acidic surface waters, we conducted experiments simulating conditions representative of natural freshwaters using solutions of standard fulvic acid and amorphous iron oxide at pH 6.0. A probe method measuring (CO2)-C-14 produced by the reaction of C-14-labeled formate with OH. was used to detect small OH. production rates without otherwise influencing the chemical reactions occurring in the experiments. Net H2O2 accumulation was simultaneously measured using an acridinium ester chemiluminescence method. Measured losses of H2O2 by reaction with Fe(II) in dark experiments produced approximately the expected quantities of OH.. The difference between H2O2 accumulation in the presence and absence of Fe(III) in fulvic acid solutions exposed to light was interpreted as the loss of H2O2 by reaction with photoproduced Fe(II), consistent with measured OH. production rates. The Fe ligand desferrioxamine mesylate eliminated both OH. production and H2O2 photoloss induced by Fe. Our results imply that when Fe is a major sink of H2O2, the photo-Fenton reaction is likely to be the most important source of OH., leading to a significant sink of organic compounds in a wide variety of sunlit freshwaters.