Seawater intrusion, a common geological process along the coastal zones, changes the groundwater properties, which are potentially associated with the groundwater copper (Cu) levels. However, there are no studies on the details of groundwater Cu levels affected by seawater intrusion. The groundwater in the seawater intrusion area of Buzhuang Town was sampled to detect the effect of seawater intrusion on groundwater Cu levels. The Cu levels in the local groundwater range between 0.92 and 4.99 μg L⁻¹, which averages about 5 times than those in the non-intrusion area. The Cu deviations (ΔCu) are positive, and increase with more intrusion of seawater. Simulation experiments also confirm that more Cu leaches from sediments when more seawater or brine water is mixed in. The groundwater Cu levels are positively correlated with TDS, Cl⁻, Br⁻, SO₄²⁻, HCO₃⁻, Na⁺, K⁺ and Mg²⁺. The Cu-bearing minerals in the local groundwater are under-saturated. The CEC of the sediment for the simulated experiments decreases with more mixture of seawater or brine water. CuCO⁰₃, Cu(OH)⁰₂, CuHCO₃⁺, Cu(CO₃)₂²⁻, CuCl₂⁻, Cu²⁺ species in the local groundwater are obviously higher than those in the non-intrusion area, and the levels of CuCl₂⁻, Cu⁺, CuCO₃, Cu²⁺, CuSO₄, CuOH⁺, CuCl⁺, Cu₂(OH)₂²⁺ are positively correlated with the degree of seawater intrusion, indicating the important role of Cl⁻, HCO₃⁻, OH⁻ complexation on groundwater Cu levels. Thus, ion competition and complexation are the important dynamics of groundwater Cu enrichment along the coastal zones. A new enrichment model of groundwater Cu in the seawater intrusion area is presented. Seawater intrusion should be taken into consideration when the enrichment mechanisms of groundwater Cu are discussed.

中文翻译：

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海水入侵区的地下水铜含量及可能的物理和化学动力学

海水入侵是沿海地区的一个常见地质过程，它改变了地下水的性质，这可能与地下水铜（Cu）的含量有关。但是，没有关于受海水入侵影响的地下水中铜含量的细节的研究。对布庄镇海水入侵区的地下水进行了采样，以检测海水入侵对地下水铜含量的影响。当地地下水中的铜含量在0.92至4.99μgL ^-1之间，平均约为非入侵区域的5倍。Cu偏差（ΔCu）为正，并且随着海水的侵入而增加。仿真实验还证实，从沉积物更多的Cu时浸出更海水或盐水的水混合地下水铜水平存在正的TDS，氯相关^- ，溴^-，SO ₄ ^2-，HCO ₃ ^{- ，}钠⁺，K ⁺和Mg ²⁺。当地地下水中的含铜矿物质欠饱和。模拟实验中沉积物的CEC随海水或盐水的更多混合而降低。CuCO ⁰ ₃，Cu（OH）⁰ ₂，CuHCO ₃ ⁺，铜（CO ₃）₂ ^2-，的CuCl ₂ ^- ，铜²⁺物种在本地地下水比在非侵入区域明显更高，和氯化亚铜的水平₂ ^- ，铜⁺，CUCO ₃，铜²⁺，硫酸铜₄，CuOH ⁺，氯化亚铜⁺，铜₂（OH）₂ ²⁺具有正海水入侵的程度相关，说明的Cl的重要作用^-，HCO ₃ ^-，OH ^-络合对地下水铜水平的影响。因此，离子竞争和络合是沿海地区地下水铜富集的重要动力。提出了一种新的海水入侵区地下水铜富集模型。在讨论地下水铜的富集机理时，应考虑海水入侵。