Mercury Redox Chemistry in Waters of the Eastern Asian Seas: From Polluted Coast to Clean Open Ocean.
Mercury Redox Chemistry in Waters of the Eastern Asian Seas: From Polluted Coast to Clean Open Ocean.
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DOI：
10.1021/acs.est.5b05372
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发表时间：
2016-02
影响因子：
11.4
通讯作者：
Zhijia Ci;Xiaoshan Zhang;Yongguang Yin;Jinsheng Chen;Shiwei Wang
中科院分区：
文献类型：
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作者：
Zhijia Ci;Xiaoshan Zhang;Yongguang Yin;Jinsheng Chen;Shiwei Wang
我们进行了孵化实验，从代表性的海洋环境中的东亚海域的海水，以确定汞（Hg）的光还原（HGR（II）），调查汞的氧化还原反应动力学，并探讨环境因素和水化学对汞的氧化还原化学的影响。结果表明，Hgr（II）占总汞（THg）的比例相当大（%Hgr（II）/THg：24.90 ± 10.55%，n = 27），且与THg呈正相关。过滤降低了高悬浮颗粒物（SPM）的沃茨的汞（II）池。总Hg（Ⅱ）光还原速率常数kr和总Hg（0）光氧化速率常数ko与光合有效辐射（PAR）呈线性正相关。在PAR为1 mmol·m（-2）·s（-1）的条件下，kr显著（p < 0.05）低于ko（kr/ko：0.86 ± 0.22）。Hg（0）的暗氧化作用显著高于Hg（II）的暗还原作用。Hg（II）暗还原与THg呈正相关，厌氧条件有利于Hg（II）暗还原。过滤显着影响高SPM的沃茨的汞光氧化还原化学。UVB辐射对Hg（II）光还原和Hg（0）光氧化都很重要，其它波段在Hg光诱导转化中的作用随水化学性质而变化。
We performed incubation experiments using seawaters from representative marine environments of the eastern Asian seas to determine the mercury (Hg) available for photoreduction (Hgr(II)), to investigate the Hg redox reaction kinetics, and to explore the effect of environmental factors and water chemistry on the Hg redox chemistry. Results show that Hgr(II) accounted for a considerable fraction of total Hg (THg) (%Hgr(II)/THg: 24.90 ± 10.55%, n = 27) and positively correlated with THg. Filtration decreased the Hgr(II) pool of waters with high suspended particulate matter (SPM). The positive linear relationships were found between pseudo-first order rate constants of gross Hg(II) photoreduction (kr) and gross Hg(0) photo-oxidation (ko) with photosynthetically active radiation (PAR). Under the condition of PAR of 1 m mol m(-2) s(-1), the kr were significantly (p < 0.05) lower than ko (kr/ko: 0.86 ± 0.22). The Hg(0) dark oxidation were significantly higher than the Hg(II) dark reduction. The Hg(II) dark reduction was positively correlated to THg, and the anaerobic condition favored the Hg(II) dark reduction. Filtration significantly influenced the Hg photoredox chemistry of waters with high SPM. UVB radiation was important for both Hg(II) photoreduction and Hg(0) photo-oxidation, and the role of other wavebands in photoinduced transformations of Hg varied with the water chemistry.