《Science of The Total Environment》杂志刊登“韩国南部地区基岩地下水中氟的地球化学性质”

作  者：Gi-Tak Chae, Seong-Taek Yun, Bernhard Mayer, Kyoung-Ho Kim, Seong-Yong Kim, Jang-Soon Kwon, Kangjoo Kim, Yong-Kwon Koh

刊  物：《Science of The Total Environment》，2007年，385卷第1-3期，272-283页

关键词：氟化物和氟中毒；基岩地下水；地质控制；水文地球化学性质

摘  要：南韩地区深层基岩地下水的高氟浓度（中位数=4.4mg/L）使之不能作为饮用水水源使用。为了对地质和地球化学性质在地下水中氟浓度的影响进行评价，本文对不同基岩中深层高温地下水（N=377）的水文地球化学性质进行研究。根据地质条件对地下水进行分组采用，并使用惠特尼U测试对氟浓度的平均数和中位数进行比较。对应不同地质条件下的氟浓度中位数排序为：变质岩≥花岗岩≥复合岩≥火山岩≥沉积岩。研究结果表明，地下水中氟化物的地质来源与变质岩和花岗岩的矿物组成相关。考虑地下水的化学性质，Na-HCO₃型地下水氟浓度最高，Ca-HCO₃型地下水氟浓度最低。地下水中的离子相关性表明，氟化物的地球化学行为与Na⁺释放和Ca²⁺去除的地球化学过程相关联。Ca和F之间行为的热力学关系表明，氟化物的浓度由萤石（CaF2）的溶解平衡所控制。换句话说，氟化物浓度的上限由Ca²⁺所控制；因此，Ca²⁺浓度在控制深层高热地下水中氟化物的行为上有着关键作用。本文研究结果表明，地下水中高浓度的氟化物来源于地质，同时当使用高浓度的Ca²⁺进行维护时氟化物可通过萤石沉淀的形式去除。该研究成果对开发深层高热地下水和处理大面积南韩地区的高氟地下水等问题的解决奠定了基础。

Fluorine geochemistry in bedrock groundwater of South Korea

Authors: Gi-Tak Chae, Seong-Taek Yun, Bernhard Mayer, Kyoung-Ho Kim, Seong-Yong Kim, Jang-Soon Kwon, Kangjoo Kim, Yong-Kwon Koh

Journal: Science of The Total Environment, Volume 385, Number 1-3 (2007), 272-283

Key words: Fluoride and fluorosis; Bedrock groundwater; Geologic control; Hydrochemistry

Abstract: High fluoride concentrations (median=4.4 mg/L) in deep bedrock groundwater of South Korea prevent the usage of it as a drinking water source. The hydrogeochemistry of deep thermal groundwaters (N=377) in diverse bedrocks has been studied in order to evaluate the geologic and geochemical controls on fluoride concentrations in groundwater. The groundwater samples were clustered geologically, and the average and median concentrations of fluoride were compared by the Mann–Whitney U test. The order of median fluoride concentration with respect to geology is as follows: metamorphic rocks≥granitoids≥complex rock≫volcanic rocks≥sedimentary rocks. This result indicates that the geological source of fluoride in groundwater is related to the mineral composition of metamorphic rocks and granitoids. With respect to groundwater chemistry, the fluoride concentration was highest in Na-HCO₃ type groundwater and lowest in Ca-HCO₃ type groundwater. Ionic relationships also imply that the geochemical behavior of fluoride in groundwater is related to the geochemical process releasing Na and removing Ca ions. The thermodynamic relationship between the activities of Ca and F indicates that fluoride concentration is controlled by the equilibrium of fluorite (CaF₂). In other words, the upper limits of fluoride concentration are determined by the Ca ion; i.e., Ca concentrations play a crucial role in fluoride behavior in deep thermal groundwater. The result of this study suggests that the high fluoride in groundwater originates from geological sources and fluoride can be removed by fluorite precipitation when high Ca concentration is maintained. This provides a basis for a proper management plan to develop the deep thermal groundwater and for treatment of high fluoride groundwater frequently found in South Korea.

原文链接：http://www.sciencedirect.com/science/article/pii/S0048969707007371