...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Environmental toxicology and chemistry >SAMPLING METHODS TO DETERMINE THE SPATIAL GRADIENTS AND FLUX OF ARSENIC AT A GROUNDWATER SEEPAGE ZONE
【24h】

SAMPLING METHODS TO DETERMINE THE SPATIAL GRADIENTS AND FLUX OF ARSENIC AT A GROUNDWATER SEEPAGE ZONE

机译：测定地下水渗流区砷空间梯度和通量的采样方法

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

Sampling techniques with centimeter-scale spatial resolution were applied to investigate biogeochemical processes controlling groundwater arsenic fate across the groundwater-surface water interface at a site characterized by fine sediments (40% sand, 46% silt, 14% clay). Freeze-core sediment collection gave more detailed and depth-accurate arsenic and iron contaminant and microbial distributions than could be obtained with the use of a hand auger. Selective chemical extractions indicated that greater than 90% of the arsenic was strongly sorbed to very amorphous iron oxyhydroxides. These solids accounted for more than 80% of the total iron in the sediments. Microbial enrichments indicated that iron-oxidizing bacteria (IOB) were up to 1% of the total bacterial abundance, whereas iron-reducing bacteria (IRB) were about two orders of magnitude less abundant than IOB. The abundance of IRB mirrored the IOB depth profile. Push-point pore-water sampling captured large amounts of sediment fines, even with controlled (20 ml/min) water withdrawal, thereby necessitating filtration before water quality analysis. Bead columns containing glass media enabled short-term (29 d) characterization of pore water-to-sediment transfer of arsenic and iron. Bead columns indicated quantitative capture of groundwater arsenic and iron during 2003, suggesting that freeze-core inventories corresponded to 2 to 20 years of accumulation, depending on location.
机译：应用具有厘米级空间分辨率的采样技术来研究生物地球化学过程，该过程控制着以细小沉积物（40％的沙子，46％的淤泥，14％的粘土）为特征的地点的地下水-地表水界面的地下水砷命运。与使用手动螺旋钻所获得的相比，冷冻芯沉积物的收集提供了更详细，深度更精确的砷和铁污染物以及微生物分布。选择性化学萃取表明，超过90％的砷被强烈吸附到非常无定形的羟基氧化铁中。这些固体占沉积物中铁总量的80％以上。微生物富集表明，铁氧化细菌（IOB）占细菌总数的1％，而铁还原细菌（IRB）的富集度比IOB少约两个数量级。大量的IRB反映了IOB深度剖面。推入式孔隙水采样即使在控制抽水量（20毫升/分钟）的情况下也能捕获大量的沉积物细颗粒，因此在水质分析之前必须进行过滤。含有玻璃介质的珠子色谱柱能够对砷和铁的孔隙水到沉积物的孔隙转移进行短期（29 d）表征。珠子柱表示2003年期间对地下水砷和铁的定量捕获，这表明冰芯核心清单对应于2到20年的积累，具体取决于位置。

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