RAPID Environmental Effects of the Coal Ash Spill and Remediation at Kingston Tennessee

许多研究表明，煤灰含有高水平的微量金属，如砷，硼和汞，可能对环境造成潜在危害。2008年12月22日发生在田纳西流域管理局（TVA）电厂金斯顿燃煤电厂的煤灰泄漏事件为研究煤灰衍生金属在区域范围内对环境的不同影响提供了一个独特的机会。杜克团队的初步调查显示，砷、锶和硼等微量金属很容易从煤灰污泥中迁移出来，并溶解在周围的地表水中。此外，它被发现，汞在下游河流沉积物中富集，反映了输运和混合的灰污泥与河流沉积物。本RAPID提案旨在进一步调查煤灰泄漏和补救活动的环境影响（例如，污泥疏浚）。本研究的重点是：（1）煤灰浸出中痕量金属含量开始影响水质的临界水沙比;（2）煤灰在下游河流沉积物中的迁移和积累;（3）硫酸盐还原菌在下游厌氧河流沉积物中产生甲基汞的潜力;（4）煤灰浸出中痕量金属含量对河流水质的影响。（4）硼和锶同位素作为阐明煤灰金属在水生系统中的地球化学工具的适用性。由于煤灰储存对环境的潜在影响是一个新的问题，由于问题的严重性。目前，美国约有500个发电厂产生约1.3亿吨煤灰，其中一半以上储存在垃圾填埋场和池塘中，例如在金斯顿煤电厂中。煤灰在池塘中储存的主要潜在危害之一是污染物的持续浸出及其向水文系统的输送。然而，这种持续的沥滤对水和生态质量的影响尚不清楚。因此，TVA煤灰泄漏提供了一个？机会？在更大的范围内调查这些过程，并确定用于调查煤灰对环境影响的地球化学工具。该项目将成为杜克大学地球与海洋科学系和土木与环境工程系两篇博士论文的基础。

Numerous studies have shown that coal ash contains high levels of trace metals such as arsenic, boron, and mercury that can potentially harm the environment. The December 22, 2008 coal ash spill at Kingston coal-burning power plant of Tennessee Valley Authority (TVA) Plant has provided a unique opportunity to study different environmental impacts of coal-ash derived metals on a regional scale. A preliminary investigation by Duke team has revealed that trace metals such as arsenic, strontium, and boron are easily mobilized from coal ash sludge and dissolved in ambient surface water. Furthermore, it was found that mercury is enriched in the downstream river sediments, reflecting transport and mixing of the ash sludge with river sediments. This RAPID proposal seeks to further investigate the environmental impacts of the coal ash spill and the remediation activities (e.g., sludge dredging) proposed by TVA. In particular, this study will focus on: (1) the critical water/sediment ratio at which the content trace metals from ash leaching begin to impact water quality; (2) the transport and accumulation of ash in downstream river sediments; (3) the potential of sulfate-reducing bacteria to generate methylmercury in the downstream anaerobic river sediments; and (4) the suitability of boron and strontium isotopes as geochemical tools for elucidating coal ash metals in aquatic systems.The potential impact of coal ash storage on the environment is an emerging issue due to the magnitude of the problem. Currently about five hundred power plants in the USA generate approximately 130 million tons of coal ash, of which more than half is stored in landfills and ponds, such as in the Kingston coal plant. One of the major potential hazards of coal ash storage in ponds is the continuous leaching of contaminants and their transport to the hydrological system. Yet, the impact of this continuous leaching on water and ecological quality is unknown. As such, the TVA coal ash spill provides an ?opportunity? to investigate these processes on a larger scale and to define biogeochemical tools for investigating the impact of coal ash on the environment. This project will form the basis for two PhD theses at Division of Earth and Ocean Sciences and Department of Civil and Environmental Engineering at Duke University.