Scholarlink

<p>This study investigated the spatial distribution and genesis of iron (Fe), manganese (Mn), arsenic (As), nitrate nitrogen (NO<sub>3</sub>-N), and ammonia nitrogen (NH<sub>3</sub>-N) in groundwater across representative regions of Beijing Plain (Yongding River alluvial fans-plains). An integrated methodology incorporating hydrochemical analysis, isotopic fingerprinting, sediment geochemistry, mineralogical and micromorphology analysis was systematically implemented. Analytical results demonstrated that groundwater As and NH<sub>3</sub>-N concentrations remained below the Class III water criteria of China’s standard for groundwater quality. Groundwater NO<sub>3</sub>-N, Fe, and Mn concentrations exceeded their Class III standards in 7.69%, 11.54%, and 19.23% of samples, respectively. Comprehensive assessments demonstrated that human health risks from groundwater hazard substances remained within acceptable thresholds. Mineralogical analysis results indicated that Fe/Mn-bearing minerals distributed in sediments were the primary geogenic sources of groundwater Fe/Mn. Furthermore, isotopic evidences coupled with hydrochemical fingerprints demonstrated that shallow groundwater NO<sub>3</sub>-N concentrations were influenced by anthropogenic nitrogen inputs. Hydrogeochemical processes induced spatially heterogeneous distributions of As, Fe, Mn, NO<sub>3</sub>-N, and NH<sub>3</sub>-N concentrations in groundwater. In the northwestern piedmont area, groundwater Mn enrichment was mainly influenced by the underlying coal seams. The central alluvial fan area exhibited co-enrichment of NO<sub>3</sub>-N and Fe primarily attributed to the combined effects of the geogenic Fe-bearing minerals dissolution under nitrifying conditions, manure and sewage inputs, and further intensified by the evaporation-concentration effects. In the southeastern alluvial plain, the co-enrichment of Fe and/or Mn concurrent with As/NH<sub>3</sub>-N concentration fluctuation was governed by nitrate reduction, iron/manganese reduction, and iron/ manganese-sulfate reduction processes. In addition, pH-dependent mineral dissolution-precipitation and adsorption-desorption further modulated the mobilization of As, Fe, and Mn in the alluvial plain area. These findings are crucial for groundwater protection and can also provide a scientific basis for ensuring drinking water security in Beijing.</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

Spatial distribution and genesis of iron, manganese, arsenic, and nitrogen in groundwater of typical areas

  • 期刊论文

  • 发表日期：

    2025年8月5日

查看全文
  • Yanyan Li,
  • Xiao Ge,
  • Yifei Du,
  • Hongrui Ding,
  • Xiang Ji,
  • Chuanye Zhou,
  • Yuanyuan Chen,
  • Di Cui,
  • Anhuai Lu

摘要

This study investigated the spatial distribution and genesis of iron (Fe), manganese (Mn), arsenic (As), nitrate nitrogen (NO3-N), and ammonia nitrogen (NH3-N) in groundwater across representative regions of Beijing Plain (Yongding River alluvial fans-plains). An integrated methodology incorporating hydrochemical analysis, isotopic fingerprinting, sediment geochemistry, mineralogical and micromorphology analysis was systematically implemented. Analytical results demonstrated that groundwater As and NH3-N concentrations remained below the Class III water criteria of China’s standard for groundwater quality. Groundwater NO3-N, Fe, and Mn concentrations exceeded their Class III standards in 7.69%, 11.54%, and 19.23% of samples, respectively. Comprehensive assessments demonstrated that human health risks from groundwater hazard substances remained within acceptable thresholds. Mineralogical analysis results indicated that Fe/Mn-bearing minerals distributed in sediments were the primary geogenic sources of groundwater Fe/Mn. Furthermore, isotopic evidences coupled with hydrochemical fingerprints demonstrated that shallow groundwater NO3-N concentrations were influenced by anthropogenic nitrogen inputs. Hydrogeochemical processes induced spatially heterogeneous distributions of As, Fe, Mn, NO3-N, and NH3-N concentrations in groundwater. In the northwestern piedmont area, groundwater Mn enrichment was mainly influenced by the underlying coal seams. The central alluvial fan area exhibited co-enrichment of NO3-N and Fe primarily attributed to the combined effects of the geogenic Fe-bearing minerals dissolution under nitrifying conditions, manure and sewage inputs, and further intensified by the evaporation-concentration effects. In the southeastern alluvial plain, the co-enrichment of Fe and/or Mn concurrent with As/NH3-N concentration fluctuation was governed by nitrate reduction, iron/manganese reduction, and iron/ manganese-sulfate reduction processes. In addition, pH-dependent mineral dissolution-precipitation and adsorption-desorption further modulated the mobilization of As, Fe, and Mn in the alluvial plain area. These findings are crucial for groundwater protection and can also provide a scientific basis for ensuring drinking water security in Beijing.