To reveal the influencing process and mechanism of seawater intrusion on groundwater Fe in coastal zones, the local groundwater in Buzhuang Town, together with those in the neighboring area where no seawater intruded, was sampled and comparatively analyzed, and the static simulation experiments were also performed in laboratory. The local groundwater has Fe levels of 6.09–196.96 μg/L, with an average of 73.38 μg/L, but groundwater Fe levels from the neighboring area are 1.3–17.7 times of those in local groundwater. Such facts indicate the groundwater Fe levels decreased due to seawater intrusion. The groundwater Fe levels are significantly negatively correlated with pH, significantly positively correlated with Ca²⁺, Mg²⁺, and positively correlated with SO₄²⁻. The simulation experiments indicate leached Fe increases with a greater mixture of seawater, increasing concentrations of NaCl and CaCl₂, but decreases with increasing NaHCO₃ concentrations. Fe(OH)₂ and Fe(OH)₃ minerals are super-saturated because of the high pH and high OH⁻ concentration resulting from seawater intrusion. By this way, the dissolving ability of groundwater Fe is restricted. Therefore, pH is the key factor determining groundwater Fe levels in coastal zones. Another, the decreasing of Ca²⁺, Mg²⁺ in groundwater decreases Fe levels because of the co-precipitation and deactivation of groundwater Fe. Salt effect and NaHCO₃ contribute less to groundwater Fe levels because of the restriction of maximum Fe solubility by high OH⁻ and super-saturation of Fe-bearing minerals. The influencing model of groundwater Fe levels under the effect of seawater intrusion is forwarded.

中文翻译：

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海水入侵区地下水铁的地球化学特征及其影响因素

为了揭示海水入侵对沿海地区地下水铁的影响过程和机理，对布庄镇的当地地下水以及附近没有海水入侵的地区的地下水进行了采样和比较分析，并进行了静态模拟实验在实验室里。当地地下水的铁含量为6.09–196.96μg/ L，平均为73.38μg/ L，但邻近地区的地下水铁含量是当地地下水的1.3–17.7倍。这些事实表明，由于海水入侵，地下水中的铁含量降低了。地下水中的Fe水平与pH呈显着负相关，与Ca 2 ⁺，Mg ²⁺呈显着正相关，与SO ₄ ^2-呈显着正相关。。模拟实验表明，随着海水的混合，NaCl和CaCl ₂浓度的增加，浸出的Fe增加，而NaHCO ₃浓度增加，浸出的Fe减少。的Fe（OH）₂和Fe（OH）_3种矿物过饱和，因为高pH值和高的OH ^-从海水入侵导致的浓度。通过这种方式，限制了地下水Fe的溶解能力。因此，pH是决定沿海地区地下水铁含量的关键因素。另一个原因是，地下水中Ca 2 ⁺，Mg ²⁺的减少会由于地下水中Fe的共沉淀和失活而降低Fe含量。盐效应和NaHCO ₃贡献较小的高OH地下水，因为最大的溶解性铁的限制铁的水平^-和Fe-轴承矿物质的超饱和。提出了海水入侵对地下水中铁含量的影响模型。