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首页> 外文期刊>Environmental Science & Technology >Impact of Halide Ions on Natural Organic Matter-Sensitized Photolysis of 17β-Estradiol in Saline Waters
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Impact of Halide Ions on Natural Organic Matter-Sensitized Photolysis of 17β-Estradiol in Saline Waters

机译：卤离子对生理盐水中自然有机物对17β-雌二醇光解的影响

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Indirect (sensitized) photolysis by natural organic matter (NOM), mainly from terrestrial sources, can be an important mechanism for attenuation of organic contaminants in estuarine waters, but the effect of salt gradients has been poorly investigated. We studied Suwannee River NOM-sensitized photolysis of 17β-estradiol (E2) in freshwater and saline media. Indirect photolysis by 4 mg-C/L SRNOM was much faster than direct photolysis, and quenching by sorbic acid verified the importance of triplet-excited NOM chromophores. Increasing halide concentrations up to seawater levels decreased the photolysis rate by 90%, with approximately 70% of this decrease associated with ionic strength effects, and the remainder due to halide-specific effects. Bromide (0.8 mM in seawater) accounted for 70% of the halide-specific effect. Halide promotion of NOM chromophore photobleaching was shown to play a major role in the halide-specific effect. Compared to chromophore bleaching,indirect photolysis of E2 was 230% faster in freshwater, but 63% slower in seawater. The involvement of hydroxyl radical (HO*) in indirect photolysis of E2 was ruled out by the lack of suppression by tert-butanol. Experiments in D_2O-H_2O demonstrated that ~1O_2 was unimportant in freshwater, but accounted for 42% of NOM-sensitized photolysis of E2 in seawater. We project that, as a parcel of water containing E2 moves through the gradient from freshwater to seawater, overall photolysis will decline due to ionic strength, indirect photolysis will decrease due to specific halide effects on NOM photobleaching, and indirect photolysis will decline relative to direct photolysis. Estuarine contaminant fate models may need to account for halide impacts on indirect photolysis of contaminants.
机译：主要来自陆地来源的天然有机物质（NOM）进行的间接（敏化）光解可能是减弱河口水中有机污染物的重要机制，但是盐梯度的影响尚未得到充分研究。我们研究了淡水和盐介质中Suwannee河NOM敏感的17β-雌二醇（E2）的光解。 4 mg-C / L SRNOM进行的间接光解比直接光解要快得多，而山梨酸的淬灭证明了三重态激发的NOM生色团的重要性。将卤化物浓度提高到海水水平会使光解速率降低90％，其中大约70％的降低与离子强度效应有关，其余的归因于卤化物特异性效应。溴化物（海水中0.8 mM）占卤化物特异性效应的70％。卤化物促进NOM生色团光漂白显示出在卤化物特异性效应中起主要作用。与发色团漂白相比，E2的间接光解在淡水中快230％，而在海水中慢63％。由于缺乏叔丁醇的抑制作用，排除了羟基自由基（HO *）参与E2的间接光解。在D_2O-H_2O中的实验表明，〜1O_2在淡水中并不重要，但占海水中E2的NOM敏化的E2光解的42％。我们预测，随着包含E2的水从淡水到海水的梯度移动，由于离子强度，整体光解将下降，由于特定卤化物对NOM光漂白的影响，间接光解将减少，相对于直接光解，间接光解将下降光解作用。河口污染物归宿模型可能需要考虑卤化物对污染物间接光解的影响。

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  • 来源
    《Environmental Science & Technology》 |2012年第13期|p.7128-7134|共7页
  • 作者

    Janel E. Grebel; Joseph J. Pignatello; William A. Mitch;

  • 作者单位

    Department of Chemical and Environmental Engineering, Yale University, Mason Lab 313b, 9 Hillhouse Ave., New Haven, Connecticut 06520, United States;

    Department of Chemical and Environmental Engineering, Yale University, Mason Lab 313b, 9 Hillhouse Ave., New Haven, Connecticut 06520, United States,Department of Environmental Sciences, Connecticut Agricultural Experiment Station, 123 Huntington St., New Haven, Connecticut 06504, United States;

    Department of Chemical and Environmental Engineering, Yale University, Mason Lab 313b, 9 Hillhouse Ave., New Haven, Connecticut 06520, United States;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
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