Heavy metal partitioning of suspended particulate matter-water and sediment-water in the Yangtze Estuary
Heavy metal partitioning of suspended particulate matter-water and sediment-water in the Yangtze Estuary
复制标题
长江口悬浮颗粒物-水和沉积物-水的重金属分配
DOI：
10.1016/j.chemosphere.2017.07.075
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发表时间：
2017-10-01
期刊：
影响因子：
8.8
通讯作者：
Shen, Zhenyao
中科院分区：
文献类型：
--
作者：
Feng, Chenghong;Guo, Xiaoyu;Shen, Zhenyao
研究了长江口7个断面3个水文季节10种重金属（As、Cd、Co、Cr、Cu、Hg、Ni、Pb、Sb和Zn）在水体、悬浮颗粒物（SPM）和沉积物中的分配特征。特别注意潮汐的作用，影响因素（悬浮颗粒物和溶解有机碳的浓度，颗粒大小），和重金属形态。重金属的SPM水和沉积物水分配系数（K-p）表现出相似的变化沿着的通道断面，虽然前者是整个河口较大。北分支由于盐度较高，大部分金属的Kp值均高于南分支。Cd、Co和As的Kp值从丰水期到枯水期普遍呈下降趋势。对角线法和配对样本t检验均表明，在涨、落潮期间，重金属不存在特定的相转移，但由于潮汐对沉积物的影响相对较小，对角线法的沉积物水Kp更集中。沉积物中大部分重金属的分配系数（尤其是SPM水的Kp）与溶解性有机碳（DOC）呈负相关，而与粒径呈正相关。在Kp和金属形态之间观察到两种类型的显著相关性（即，可交换的、碳酸盐的、可还原的、有机的和残余的部分），其可用于识别主要的相分配机制（例如，吸附或解吸）的重金属。(C)2017爱思唯尔有限公司版权所有
The partitioning of ten heavy metals (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, and Zn) between the water, suspended particulate matter (SPM), and sediments in seven channel sections during three hydrologic seasons in the Yangtze Estuary was comprehensively investigated. Special attention was paid to the role of tides, influential factors (concentrations of SPM and dissolved organic carbon, and particle size), and heavy metal speciation. The SPM water and sediment water partition coefficients (K-p) of the heavy metals exhibited similar changes along the channel sections, though the former were larger throughout the estuary. Because of the higher salinity, the Kp values of most of the metals were higher in the north branch than in the south branch. The Kp values of Cd, Co, and As generally decreased from the wet season to the dry season. Both the diagonal line method and paired samples t-test showed that no specific phase transfer of heavy metals existed during the flood and ebb tides, but the sediment water Kp was more concentrated for the diagonal line method, owing to the relatively smaller tidal influences on the sediment. The partition coefficients (especially the Kp for SPM water) had negative correlations with the dissolved organic carbon (DOC) but positive correlations were noted with the particle size for most of the heavy metals in sediment. Two types of significant correlations were observed between Kp and metal speciation (i.e., exchangeable, carbonate, reducible, organic, and residual fractions), which can be used to identify the dominant phase-partition mechanisms (e.g., adsorption or desorption) of heavy metals. (C) 2017 Elsevier Ltd. All rights reserved.