• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >The effect of mercury speciation and meteorological processing on concentrations, transport and deposition of atmospheric mercury.
【24h】

The effect of mercury speciation and meteorological processing on concentrations, transport and deposition of atmospheric mercury.

机译：汞形态和气象处理对大气中汞的浓度，迁移和沉积的影响。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The toxic trace element mercury can be transported locally, regionally or globally within the atmosphere before deposition to a watershed. The fate of atmospheric mercury is dependent on its chemical and physical form, which determine its deposition rate under different environmental conditions. The importance of these influences on atmospheric mercury was investigated in dew, clouds and the coastal atmosphere.; Measurements of mercury in dew were made at locations in Michigan and Florida. The mercury in dew was accounted for by deposition of particulate mercury and reactive gaseous mercury (RGM). RGM concentrations were significantly reduced at the onset of dew with RGM deposition velocities ranging from 0.2 to 1.3 cm/s. In areas with frequent dew formation and low precipitation, dew appears to be an important contribution to mercury deposition.; Measurements of mercury in non-precipitating cloud water were made at Mt. Mansfield, VT. Concentrations of mercury and other trace elements with predominately anthropogenic, but not crustal origin, were higher in cloud water than in precipitation. This is hypothesized to be caused by (1) greater in-cloud scavenging of crustal aerosol in precipitating than non-precipitating clouds and (2) more efficient below-cloud scavenging of crustal than anthropogenic aerosol by rain. Concentrations of mercury in cloud water were explained by transport history, with the highest concentrations from the Mid-Atlantic and Ohio River Valley.; Atmospheric mercury measurements along the Atlantic Coast of Florida revealed low concentrations of Hg0(g) and RGM in the marine boundary layer. This indicated that the ocean is not a large net source of mercury to the Eastern Florida shoreline. Higher daytime peaks in diurnal cycles of RGM were observed under anthropogenic influence, possibly produced by reaction with a photochemical oxidant. Particulate mercury concentrations could not be explained by sea spray alone, suggesting that gaseous Hg diffused into the aerosol. Deposition of aerosol elevated in Hg via this process may constitute an important global mercury flux to the oceans.; A sampling artifact was observed in which mercury was lost from aerosols as sampling duration increased. The cause of this artifact is hypothesized to be reduction of Hg2+(aq) to Hg0 (aq) that volatilizes off the filter.
机译：有毒的微量元素汞可在沉积到分水岭之前在大气中局部，区域或全球迁移。大气中汞的命运取决于其化学和物理形式，这决定了其在不同环境条件下的沉积速率。在露水，云层和沿海大气中研究了这些影响对大气中汞的重要性。在密歇根州和佛罗里达州进行了露水中汞的测量。露水中的汞是由颗粒状汞和反应性气态汞（RGM）的沉积引起的。露水开始时RGM浓度显着降低，RGM沉积速度为0.2到1.3 cm / s。在露水形成频繁且降水低的地区，露水似乎是汞沉积的重要贡献。非沉淀云水中的汞含量在Mt.佛蒙特州曼斯菲尔德。云水中的汞和其他微量元素（主要是人为因素而不是地壳来源）的浓度高于降水。据推测，这是由于（1）降水中的地壳气溶胶在云中的清除比非降水云更严重;（2）雨水比人为的气溶胶对地壳的云下清除效率更高。迁移历史解释了云水中汞的浓度，其中大西洋中部和俄亥俄州河谷的汞含量最高。佛罗里达大西洋沿岸的大气汞测量表明，海洋边界层中的Hg 0 （g）和RGM浓度较低。这表明海洋不是佛罗里达州东部海岸线的主要汞净来源。在人为影响下，RGM的昼夜周期中出现了较高的白天峰值，这可能是与光化学氧化剂反应产生的。单独的海浪无法解释颗粒状汞的浓度，表明气态Hg扩散到气溶胶中。通过这一过程沉积的汞中升高的气溶胶可能构成重要的全球汞向海洋的通量。观察到一个采样伪像，其中随着采样持续时间的增加，气溶胶中的汞损失了。据推测，该伪像的原因是将Hg 2 + （aq）还原为Hg 0 （aq）会使过滤器挥发。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号