EAGER -- Field tests of low-impact treatment for acid mine drainage

EAGER——酸性矿山排水低影响处理现场试验

• 批准号: 1138716
• 负责人: Richard Yuretich
• 金额: $ 3万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1138716&HistoricalAwards=false
• 关键词: EAGER; Field; tests; low; impact

This exploratory project will investigate field techniques by which natural microbial processes can be stimulated to reverse the conditions of acid-mine drainage. Acid-mine drainage is produced when sulfide minerals excavated during mining operations are exposed to oxidation and hydrolysis at the Earth's surface. However, within the soils and stream deposits of these mine sites there is a community of microorganisms, largely sulfate-reducing and iron-reducing bacteria, that have the capability of reversing the conditions of low pH and elevated heavy metal content typical of affected waters. A field study site will be established at the outflow of Davis Mine, a long-abandoned pyrite mine in western Massachusetts, to monitor the changes in geochemistry that result from the introduction of a reactive fill into the outflow. This reactive fill will consist of a mix of limestone and organic compost that will provide an initial neutralization of the acidic water and a carbon source to stimulate the microbial population. Water samples will be collected at regular intervals upstream and downstream of the experiment site to monitor changes in chemistry resulting from the introduction of the mixture. If persistent positive changes are noted, the microbial communities within the stream sediments both before and after introduction of the reactive fill will be assayed. The results of the investigation will provide important data on the conditions required for successful growth and development of the in situ iron- and sulfate-reducing bacteria that can help in a long-term reversal of acid generation and metal transport. Acid-mine drainage (AMD) is a global problem that is often associated with extensive coal mining, but it occurs frequently around abandoned base-metal mines in remote areas. Cleaning up these sites often involves elaborate engineering efforts that are both costly and environmentally disruptive. However, if the conditions within the surface waters of an affected mine site can be modified so that the natural community of sulfate- and iron-reducing bacteria can grow and prosper, these microorganisms could establish a self-sustaining method for neutralizing the excess acidity and removing the metals. This project will examine the processes that can optimize the conditions for such a beneficial outcome.

该探索性项目将研究现场技术，通过这些技术可以刺激自然微生物过程来扭转酸性矿山排水条件。 当采矿作业中挖掘的硫化物矿物暴露在地球表面的氧化和水解作用时，就会产生酸性矿山排水。然而，在这些矿区的土壤和溪流沉积物中存在着一个微生物群落，主要是硫酸盐还原菌和铁还原菌，它们能够扭转受影响水域典型的低 pH 值和重金属含量升高的状况。 将在戴维斯矿（马萨诸塞州西部一座长期废弃的黄铁矿矿）的出口处建立一个实地研究地点，以监测由于在出口中引入反应性填充物而导致的地球化学变化。这种反应性填充物由石灰石和有机堆肥的混合物组成，可初步中和酸性水和刺激微生物种群的碳源。将定期在实验地点的上游和下游采集水样，以监测由于引入混合物而引起的化学变化。如果注意到持续的积极变化，则将在引入反应性填充物之前和之后对溪流沉积物内的微生物群落进行分析。研究结果将提供有关原位铁和硫酸盐还原细菌成功生长和发育所需条件的重要数据，这些细菌有助于长期逆转酸的产生和金属运输。酸性矿井排水 (AMD) 是一个全球性问题，通常与大规模煤炭开采有关，但它经常发生在偏远地区废弃的贱金属矿井周围。清理这些场地通常需要复杂的工程工作，不仅成本高昂，而且还会破坏环境。然而，如果可以改变受影响矿区地表水中的条件，使硫酸盐和铁还原菌的自然群落能够生长和繁荣，这些微生物就可以建立一种自我维持的方法来中和过量的酸度并去除金属。该项目将研究可以优化条件以获得这种有益结果的流程。