Evaluations of submarine groundwater discharge and associated heavy metal fluxes in Bohai Bay, China.
Evaluations of submarine groundwater discharge and associated heavy metal fluxes in Bohai Bay, China.
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DOI：
10.1016/j.scitotenv.2019.133873
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发表时间：
2019-12
期刊：
影响因子：
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通讯作者：
Qianqian Wang;Hailong Li;Yan Zhang;Xuejing Wang;Chengcheng Zhang;Kai Xiao;W. Qu
中科院分区：
文献类型：
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作者：
Qianqian Wang;Hailong Li;Yan Zhang;Xuejing Wang;Chengcheng Zhang;Kai Xiao;W. Qu
海底地下水排放（SGD）已被认为是沿海海洋溶解性重金属的重要来源。渤海湾是中国渤海第二大海湾，环境问题严重。然而，海湾中SGD和SGD衍生的重金属通量很少被报道。在这项研究中，我们建立了考虑再循环海水造成的镭损失的质量平衡模型，以估计2017年5月渤海湾的水龄、SGD和SGD衍生的重金属通量。根据潮汐棱柱模型，估算水龄为56.7 ~ 85.0 天。结合水盐质量平衡模型，估算海底淡水地下水流量（SFGD）为（3.5-9.3） × 107m3d−1。镭质量平衡模型估算的SGD通量为（3.2 ~ 7.7） × 108m3d−1，比黄河在采样期间的流量大一个数量级。SGD-derived重金属通量估计(0.2 - -6.0) × 107摩尔d−1铁、(1.2 - -2.7) × 107摩尔d−1 Mn,(3.0 - -8.2) × 105摩尔d−1锌、(2.7 - -7.4) × 104摩尔d−1 Cr和(0.6 - -1.8) × 103摩尔d−1 Cd,显著高于当地的河流。研究表明，SGD是渤海湾重金属（Mn、Zn和Fe）的重要来源，可能对沿海地区的金属收支和生态环境产生重要影响。
Submarine groundwater discharge (SGD) has been recognized as an important source of dissolved heavy metals to the coastal ocean. Bohai Bay, the second largest bay of Bohai Sea in China, is subjected to serious environmental problems. However, SGD and SGD-derived heavy metal fluxes in the bay are seldom reported. In this study, we present mass balance models considering the radium losses caused by recirculated seawater to estimate water age, SGD and SGD-derived heavy metal fluxes in Bohai Bay during May 2017. The water age is estimated to be 56.7–85.0 days based on tidal prism model. By combining water and salt mass balance models, submarine fresh groundwater discharge (SFGD) is estimated to be (3.5–9.3) × 107m3d−1. The SGD flux estimated by the radium mass balance models is (3.2–7.7) × 108m3d−1, an order of magnitude larger than the discharge of the Yellow River during the sampling period. SGD-derived heavy metal fluxes were estimated to be (0.2–6.0) × 107mol d−1for Fe, (1.2–2.7) × 107mol d−1for Mn, (3.0–8.2) × 105mol d−1for Zn, (2.7–7.4) × 104mol d−1for Cr and (0.6–1.8) × 103mol d−1for Cd, which are significantly higher than those from local rivers. This study reveals that SGD is a significant source of heavy metals (Mn, Zn and Fe) into Bohai Bay, which may have important influences on the metal budgets and ecological environments in coastal areas.