Phase speciation of mercury (Hg) in coastal water of the Yellow Sea, China
Phase speciation of mercury (Hg) in coastal water of the Yellow Sea, China
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中国黄海近海汞（Hg）的物相形态
DOI：
10.1016/j.marchem.2011.06.004
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发表时间：
2011-09-20
期刊：
影响因子：
3
通讯作者：
Niu, Zhenchuan
中科院分区：
文献类型：
--
作者：
Ci, Zhijia;Zhang, Xiaoshan;Niu, Zhenchuan
本研究旨在探讨中国东部大陆边缘黄海沿岸高流速潮场水体中汞（Hg）的相位分布及影响其分布和行为的过程的相对重要性。采用超痕量汞技术，在4个不同季节，每隔1 ~ 3 h测定未过滤和过滤（0.45 μ m）水中的总汞（THg）和活性汞（RHg）。沿海水体中汞含量呈典型的未污染沿海地区水平。未经过滤的水中THg的平均（+/- SD）浓度为13.4 +/- 3.9 pM，范围为6.7 ~ 27.5 pM， RHg占相当大的比例（%RHg/THg = 36.9%）。未过滤水样中颗粒汞（PHg）为优势相（%PHg/THg = 70 +/- 11%），颗粒相和溶解相（0.45 μ m）中Hg的分布系数（Log K-d）平均为4.96 +/- 0.20，范围为4.26 ~ 5.38。风和潮汐混合引起的水中悬浮颗粒物（SPM）的增加可能是未过滤THg变化的主要原因。在溶解相中，RHg占THg的主要部分（%RHg/THg = 86 +/- 16%）。溶解相中溶解有机碳（DOC）与THg的弱相关性表明，本研究区Hg可能主要来源于大气沉积，也反映了水柱中其他竞争配体（如Cl-）的重要性。有趣的是，覆盖四个不同季节的测量结果显示，这些汞物种没有季节性。虽然在测量中存在一些不确定性，但使用未过滤和溶解样品之间RHg的差异表明，相当一部分（28 +/- 19%）的RHg可以与SPM结合。(C) 2011 Elsevier B.V.版权所有
The objective of this study is to investigate the phase distribution of mercury (Hg) in water and the relative importance of processes affecting its distribution and behavior at a coastal site of the Yellow Sea with high tidal current speeds in the eastern continental margin of China. Total Hg (THg) and reactive Hg (RHg) were measured in unfiltered and filtered (0.45 mu m) water in four different seasons at 1-3 h intervals using ultra-trace Hg techniques. The Hg in this coastal water showed typical Hg-unpolluted coastal region levels. Mean (+/- SD) concentrations of THg in unfiltered water were 13.4 +/- 3.9 pM with a range of 6.7 to 27.5 pM and a considerable RHg fraction (%RHg/THg = 36.9%). Particulate Hg (PHg) was the dominant phase in unfiltered water samples (%PHg/THg = 70 +/- 11%), and the distribution coefficient (Log K-d) of Hg in particulate and dissolved (0.45 mu m) phases averaged 4.96 +/- 0.20 with a range of 4.26 to 5.38. Enhanced suspended particulate matter (SPM) in water induced by wind and tidal mixing probably explained most of the variation in the unfiltered THg. In the dissolved phase, RHg accounted for a major fraction of THg (%RHg/THg = 86 +/- 16%). The weak correlation between dissolved organic carbon (DOC) and THg in the dissolved phase indicated that Hg in this study region might primarily originate from atmospheric deposition and also reflected the importance of other competing ligands (e.g., Cl-) in the water column. Interestingly, measurements covering four different seasons showed no seasonality in these Hg species. Although there was some uncertainty in the measurements, using the difference of RHg between unfiltered and dissolved samples revealed that a considerable fraction (28 +/- 19%) of RHg could bind to SPM. (C) 2011 Elsevier B.V. All rights reserved.