Modification of ozone deposition and I2 emissions at the air-aqueous interface by dissolved organic carbon of marine origin.
Modification of ozone deposition and I2 emissions at the air-aqueous interface by dissolved organic carbon of marine origin.
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海洋来源的溶解有机碳改变空气-水界面处的臭氧沉积和 I2 排放。
DOI：
10.1021/es4011459
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发表时间：
2013
影响因子：
11.4
通讯作者：
Shaw MD
中科院分区：
文献类型：
--
作者：
Shaw MD
臭氧（O3）和碘（I-）在表面微层（SML）上的反应被认为是O3在公海沃茨上干沉积的主要化学贡献者，并且最近也被证明会产生对环境重要的气态分子碘（I2）。在这里，我们调查这个反应是如何受到海洋来源的溶解有机碳（DOC）的存在下，使用非均相流反应器和检测的气态I2溶剂捕集和UV/维斯光谱。臭氧对沿岸海水DOC的反应性（λ）约为500（420-580）s-1，比典型海洋浓度（0.5-1 × 10- 7 M）下的碘化物反应性（λ）高2-5倍。将从近海海水中提取的高浓度DOC添加到I-溶液（1 × 10- 5 M）中，使DOC和I-对O3的相对反应性（λDOC/λI）在天然海水的预期范围内。随着DOC浓度的增加，气态I2的释放和水相I2的损失均减少，在代表开阔海洋沃茨的λDOC/λ I（0.5-1）条件下，I2的释放总体上被抑制了约2倍。SML的动力学模型表明，DOC与I-的竞争与界面O3反应，也没有I2和次碘酸（HOI）通过与DOC的反应量增加的直接损失，可以充分解释这些结果。我们的结论是，I2排放DOC的抑制主要是一个物理效应所产生的净转移的I2从水到气相的减少，建议由最近的实验室研究。
The reaction between gaseous ozone (O3) and aqueous iodide (I–) at the surface microlayer (SML) is believed to be a major chemical contributor to the oceanic dry deposition of O3over open ocean waters and has also recently been shown to produce environmentally significant quantities of gaseous molecular iodine (I2). Here we investigate how this reaction is affected by the presence of dissolved organic carbon (DOC) of marine origin, using a heterogeneous flow reactor and detection of gaseous I2by solvent trapping and UV/vis spectroscopy. Ozone deposition measurements over coastal seawater implied an O3reactivity (λ) toward coastal marine DOC of ∼500 (420–580) s–1, 2–5 times higher than that toward iodide at typical ocean concentrations (∼0.5–1 × 10–7M). We added varying amounts of highly concentrated DOC extracted from coastal seawater to I–solutions (1 × 10–5M) such that the relative reactivities of DOC and I–toward O3(λDOC/λI) were in the expected range for natural seawater. The evolution of gaseous I2and the loss of aqueous I–both reduced as DOC concentrations increased, with an overall suppression of I2emissions of about a factor of 2 under conditions of λDOC/λIrepresentative of open ocean waters (0.5–1). A kinetic model of the SML suggested that neither competition of DOC with I–for reaction with interfacial O3, nor direct loss of I2and hypoiodous acid (HOI) through reaction with increasing quantities of DOC, can fully explain these results. We conclude that the suppression of I2emissions by DOC is largely a physical effect arising from a decrease in the net transfer of I2from the aqueous to gas phase, as suggested by recent laboratory studies.
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影响因子：
1.5
作者：
K. Sebők;T. Körtvélyesi
通讯作者：
T. Körtvélyesi
模拟沿海海洋环境中的分子碘排放：与新颗粒形成的联系
影响因子：
6.3
作者：
A. Saiz‐Lopez;J. Plane;G. Mcfiggans;P. Williams;S. M. Ball;M. Bitter;Roderic L. Jones;C. Hongwei;T. Hoffmann
通讯作者：
T. Hoffmann
影响因子：
64.8
作者：
Read, Katie A.;Mahajan, Anoop S.;Plane, John M. C.
通讯作者：
Plane, John M. C.
影响因子：
5.2
作者：
Martino, Manuela;Mills, Graham P.;Liss, Peter S.
通讯作者：
Liss, Peter S.
对雪、湿裸土和湖水的小臭氧通量进行现场测量
影响因子：
4.3
作者：
M. Wesely;David R. Cook;R. Williams
通讯作者：
R. Williams