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

田纳西州金斯敦煤灰泄漏和修复对环境的快速影响

• 批准号: 0935972
• 负责人: Avner Vengosh
• 金额: $ 10.54万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-15 至 2010-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0935972&HistoricalAwards=false
• 关键词: RAPID; Environmental; Effects; Coal; Ash

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.

大量研究表明，煤灰中含有大量的微量金属，如砷、硼和汞，这些金属可能对环境造成潜在危害。2008年12月22日，田纳西河谷管理局（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。杜克大学研究小组的一项初步调查显示，砷、锶和硼等微量金属很容易从煤灰污泥中动员起来，并溶解在周围的地表水中。此外，发现下游河流沉积物中汞富集，反映了灰污泥与河流沉积物的运输和混合。这项RAPID提案旨在进一步调查煤灰泄漏和TVA提议的补救活动（例如污泥疏浚）对环境的影响。本研究将重点关注：(1)灰浸出中微量金属含量开始影响水质的临界水沙比；(2)下游河流沉积物中灰分的搬运和堆积；(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)硼和锶同位素作为水生系统中煤灰金属地球化学工具的适用性。由于问题的严重性，煤灰储存对环境的潜在影响是一个新出现的问题。目前，美国约有500家发电厂产生约1.3亿吨煤灰，其中一半以上储存在垃圾填埋场和池塘中，比如金斯顿燃煤电厂。煤灰池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，这种持续的浸出对水和生态质量的影响尚不清楚。因此，TVA煤灰泄漏事件提供了一个“机会”。在更大范围内研究这些过程，并定义生物地球化学工具来研究煤灰对环境的影响。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。