Has submarine groundwater discharge been overlooked as a source of mercury to coastal waters?
Has submarine groundwater discharge been overlooked as a source of mercury to coastal waters?
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DOI：
10.1021/es0622453
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发表时间：
2007-05-01
影响因子：
11.4
通讯作者：
Gonneea, Meagan Eagle
中科院分区：
文献类型：
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作者：
Bone, Sharon E.;Charette, Matthew A.;Gonneea, Meagan Eagle
我们测量了瓦阔特湾（马萨诸塞州）地下水、含水层沉积物和地表水中的汞（Hg），发现这种有毒金属（范围：< 3.2-262 pM）在地下河口中释放，在海湾的地表沃茨中发现了类似的高水平（范围：18-256 pM）。没有溶解的物种（DOC，氯化物，和铁）通常观察到的影响汞分配相关以及所观察到的汞浓度。据推测，这部分是由于汞在时间和空间上对含水层砂的可变负载，以及通过含水层的地下水流量的季节性。研究地点的含水层沉积物样本的汞含量范围为< 1至12.5皮摩尔/克沉积物，表明对数Kd值约为1。我们推测，这是由于含水层沉积物中典型的有机碳含量低。最后，据估计，海底地下水排放为海湾提供了0.47-1.9 nmol Hg m（-2）day（-1），这比美国东北部的大气沉降率高一个数量级。
We measured the mercury (Hg) in groundwater, aquifer sediments, and surface water in Waquoit Bay (Massachusetts) and found that this toxic metal (range: < 3.2-262 pM) was being released within the subterranean estuary, with similarly high levels (range: 18-256 pM) found in the surface waters of the bay. None of the dissolved species (DOC, chloride, and Fe) normally observed to influence Hg partitioning correlated well with the observed Hg concentrations. It was hypothesized that this was in part due to the variable loading in time and space of Hg onto the aquifer sands in combination with the seasonality of groundwater flow through the aquifer. Aquifer sediment samples from the study site ranged from < 1 to 12.5 pmol of Hg/g of sediment, suggesting log K-d values on the order of 1. We hypothesize that this was due to the low organic carbon content typical of the aquifer sediments. Last, it was estimated that submarine groundwater discharge supplied 0.47-1.9 nmol of Hg m(-2) day(-1) to the bay, which is an order of magnitude higher than the atmospheric deposition rate for the northeastern U.S.