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Trace metal applications in atmospheric and watershed dynamics: Case studies of mercury deposition in New England and bedrock groundwater-surface water mixing.

机译：痕量金属在大气和流域动力学中的应用：新英格兰汞沉积和基岩地下水-地表水混合的案例研究。

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摘要

The studies presented in this dissertation focus on the environmental chemistry of two trace metals, mercury (Hg) and strontium (Sr). Both are naturally occurring and exist in the environment at trace levels.;Chapters II-IV of this dissertation focus on understanding the atmospheric chemistry of Hg and the wet and dry deposition of this toxic element. Chapter II presents results from Hg wet deposition measurements and ambient reactive gaseous Hg (RGM) measurements collected at Thompson Farm located in Durham, NH over a 3 year time period. The duration of this study allowed for seasonal and inter-annual comparisons. Seasonally, Hg wet deposition was greatest in the summer and spring and lowest in the winter and fall. Evidence of ineffective scavenging of RGM is provided due to the less frequent depletion of RGM during winter precipitation events in comparison with other seasons. RGM dry deposition estimates based on real time concentration measurements are greatest during the winter and spring. Ratios of the seasonal Hg wet deposition to RGM dry deposition vary greatly from 1.6 to 80.;A comparison between Hg wet deposition at Thompson Farm and a marine site, Appledore Island, is included in Chapter III. There were no significant differences in event concentration or deposition between the two sites, however, the sample collection efficiency varied greatly between the sites and may effect the results. Additionally, major ion concentrations were measured at the Appledore Island site and compared to the Hg concentrations. The analytical results coupled with air mass back trajectories suggest that the greatest amount of Hg wet deposition occurs when polluted continental air mixes with marine air.;A new filter extraction method for determining the environmentally mobile Hg concentration in bulk aerosol filters is presented in Chapter IV. This method is applied during a 2 week intensive sampling campaign at Appledore Island during summer 2009.;Chapter V explores the use of Sr isotope ratios to determine groundwater inputs to the Lamprey River. The groundwater and surface waters in the watershed exhibit large differences in 87Sr/86Sr indicating this geochemical indicator could be a useful tool in hydrogeologic studies of the watershed.
机译：本论文的研究重点是汞（Hg）和锶（Sr）两种痕量金属的环境化学。两者都是天然存在的，并且以痕量水平存在于环境中。本论文的第二章至第四章着重于了解汞的大气化学以及该有毒元素的湿法和干法沉积。第二章介绍了在3年时间内从位于新罕布什尔州达勒姆市的汤普森农场收集的汞湿沉降测量结果和周围反应性气态汞（RGM）测量结果。这项研究的持续时间允许进行季节和年度间的比较。季节性而言，汞湿沉降在夏季和春季最大，而在冬季和秋季最低。由于与其他季节相比，冬季降水事件期间RGM的消耗较少，因此提供了RGM清除无效的证据。在冬季和春季，基于实时浓度测量值的RGM干沉降估算最大。季节性汞湿沉降与RGM干沉降的比率在1.6至80之间变化很大;第三章对汤普森农场和海洋站点Appledore岛的汞湿沉降进行了比较。两个地点之间的事件浓度或沉积没有显着差异，但是，两个地点之间的样品收集效率差异很大，并且可能影响结果。此外，在Appledore Island站点测量了主要离子浓度，并将其与Hg浓度进行了比较。分析结果与空气质量后移轨迹相结合，表明当污染的大陆空气与海洋空气混合时，汞湿沉降量最大。第四章介绍了一种用于确定散装气溶胶过滤器中环境活动汞浓度的新过滤器提取方法。该方法在2009年夏季的Appledore岛进行了为期2周的密集采样活动中应用。第五章探讨了使用Sr同位素比确定向Lamprey河的地下水输入量。流域中的地下水和地表水的87Sr / 86Sr差异很大，表明该地球化学指标可能是流域水文地质研究的有用工具。

著录项

  • 作者

    Lombard, Melissa A.;

  • 作者单位

    University of New Hampshire.;

  • 授予单位 University of New Hampshire.;
  • 学科 Atmospheric Chemistry.;Biogeochemistry.;Environmental Sciences.;Geochemistry.
  • 学位 Ph.D.
  • 年度 2012
  • 页码 118 p.
  • 总页数 118
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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