Scholarlink

<p>Contamination of groundwater has become a critical environmental concern, prompting international inquiries. In this study, the impacts of natural and anthropogenic factors in the granite bedrock groundwater system were identified based on the hydrogeochemical compositions including environmental isotopes (δ<sup>18</sup>O, δ<sup>2</sup>H, <sup>222</sup>Rn, δ<sup>34</sup>S<sub>SO4</sub>, δ<sup>18</sup>O<sub>SO4</sub>) using multivariate statistical methods. Hierarchical clustering analysis classified the groundwater samples into three groups for both dry and wet seasons. The first group, observed in both seasons, represents groundwater influenced by water–rock interactions in low flow and also demonstrates anthropogenic contamination near densely populated residential areas. The second group corresponds to higher flow groundwater, where surface water interaction affects with minimal anthropogenic impact. The third group characterizes relatively radon-contaminated groundwater, representing the predominant groundwater type in the study area. The isotope mixing model based on δ<sup>34</sup>S<sub>SO4</sub> and δ<sup>18</sup>O<sub>SO4</sub> identified proportional contributions of precipitation (~ 14%), sewage (~ 22%), soil (~ 78%), and sulfide oxidation (~ 27%) sources. The redox processes of bacterial sulfate reduction and sulfide oxidation were determined to have a minimal influence on sulfur isotope fractionation within the system. By integrating hydrogeochemical analysis, sulfur isotopes, and the MixSIAR model to trace sulfate sources, uncertainties are able be accounted in source contributions. The groundwater system was mainly influenced by natural factors through infiltration, particularly via the unsaturated soil layer during the wet season. This also indicates enhanced mixing of multiple factors during the recharge or discharge processes triggered by rainfall events. In contrast, anthropogenic contributions declined indicating strong seasonal influences, especially from sewage which decreased from 22 to 6% in groundwater most affected by human activity. This highlights the role of rainfall in diluting human-induced contaminants from the groundwater system. To understand the fractured granite groundwater system, a conceptual model was developed, detailing groundwater types and identifying sulfur sources.&#xa0;</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Natural and anthropogenic factors controlling hydrogeochemical processes in a fractured granite bedrock aquifer, Korea

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年4月30日

查看全文
  • Jiyun Kim,
  • Jaeyeon Kim,
  • Dugin Kaown,
  • Won-Tak Joun

摘要

Contamination of groundwater has become a critical environmental concern, prompting international inquiries. In this study, the impacts of natural and anthropogenic factors in the granite bedrock groundwater system were identified based on the hydrogeochemical compositions including environmental isotopes (δ18O, δ2H, 222Rn, δ34SSO4, δ18OSO4) using multivariate statistical methods. Hierarchical clustering analysis classified the groundwater samples into three groups for both dry and wet seasons. The first group, observed in both seasons, represents groundwater influenced by water–rock interactions in low flow and also demonstrates anthropogenic contamination near densely populated residential areas. The second group corresponds to higher flow groundwater, where surface water interaction affects with minimal anthropogenic impact. The third group characterizes relatively radon-contaminated groundwater, representing the predominant groundwater type in the study area. The isotope mixing model based on δ34SSO4 and δ18OSO4 identified proportional contributions of precipitation (~ 14%), sewage (~ 22%), soil (~ 78%), and sulfide oxidation (~ 27%) sources. The redox processes of bacterial sulfate reduction and sulfide oxidation were determined to have a minimal influence on sulfur isotope fractionation within the system. By integrating hydrogeochemical analysis, sulfur isotopes, and the MixSIAR model to trace sulfate sources, uncertainties are able be accounted in source contributions. The groundwater system was mainly influenced by natural factors through infiltration, particularly via the unsaturated soil layer during the wet season. This also indicates enhanced mixing of multiple factors during the recharge or discharge processes triggered by rainfall events. In contrast, anthropogenic contributions declined indicating strong seasonal influences, especially from sewage which decreased from 22 to 6% in groundwater most affected by human activity. This highlights the role of rainfall in diluting human-induced contaminants from the groundwater system. To understand the fractured granite groundwater system, a conceptual model was developed, detailing groundwater types and identifying sulfur sources.