Collaborative Research: Optimization of metal attenuation in biologically-active remediation systems

合作研究：生物活性修复系统中金属衰减的优化

• 批准号: 1743046
• 负责人: Cara Santelli
• 金额: $ 10.06万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2017-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1743046&HistoricalAwards=false
• 关键词: Collaborative; Research; Optimization; metal; attenuation

CBET 1336496/1336247Colleen Hansel/Cara SantelliWoods Hole Ocean Inst. /Smithsonian InstututionCoal-mining activities have resulted in worldwide environmental pollution due to the production of acidic, metal-rich waters that damage entire ecosystems and contaminate water supplies compromising public health. Coal mine drainage (CMD) throughout the Appalachian region contains particularly elevated concentrations of dissolved manganese (Mn), that at such high levels may lead to neurological disorders. One of the most promising and economically feasible approaches to treat metal-laden CMD containing elevated Mn are biologically active limestone treatment beds. Limestone is used to raise the pH of the contaminated waters to promote growth of microorganisms that can transform (via oxidation reactions) soluble Mn to solid Mn oxide minerals that are subsequently retained within the treatment beds. Formation of these minerals effectively removes Mn from the water and also produces a substrate that serves as a water treatment filter, effectively removing additional contaminants, such as cobalt, zinc, and nickel, from CMD. At this time, the successful removal of Mn and other metal contaminants from mine waters is highly variable and as low as 20% removal of Mn in some systems in Pennsylvania. Success of these treatment systems is currently limited by an insufficient knowledge of the individual and collective activities of microbial populations and the optimal conditions for biologically mediated Mn oxide formation. This research will address these knowledge gaps by simulating limestone treatment systems under controlled laboratory conditions to better establish the most effective biogeochemical conditions for stimulating both microbial growth and subsequent metal attenuation in CMD treatment systems. Specifically, the project will first identify the most effective microbial species and nutrient conditions (e.g., organic carbon and nitrogen composition) stimulating optimal Mn oxide formation by pure and mixed laboratory cultures of bacteria, fungi, and algae previously isolated from CMD treatment systems. These vital nutrient and microbiological conditions will then be employed and tested in laboratory-simulated treatment systems to further optimize Mn removal and precipitation efficiencies by complex microbial assemblages and the activity of key microbial species. Throughout the experiments, the microbial population structure and community interactions that impact Mn removal and Mn oxide formation will be identified. The composition and stability of the biologically precipitated Mn oxide minerals and their efficacy in removing metal contaminants will also be assessed. The development of successful and cost-effective approaches for cleaning contaminated environments and water supplies is an immediate priority. This project will answer key scientific questions limiting the success of biologically stimulated treatment processes and optimize low-cost, green technologies currently employed throughout the world in an attempt to clean environments devastated by mine drainage. Essential knowledge gained by this project will be conveyed to scientists, engineers, educators, and government regulators for direct application to limestone treatment systems currently being used at hundreds of sites in Appalachia to treat coal mine drainage. An equally important goal of this project is to educate future generations and the general public on the causes, effects, and solutions to mine drainage. The PIs will integrate this research into two outreach activities, including (1) high school science teacher internships to aid in the development of new curricula that will engage underrepresented students in STEM fields and introduce them to green technologies used to treat environmental pollution and (2) informal presentations and inquiry-based learning exercises at the National Museum of Natural History, Smithsonian Institution, to communicate science activities and products to the general public and provide opportunities for visitors to ask questions and personally interact with the scientists.

煤炭开采活动造成了世界范围内的环境污染，因为产生了酸性、富含金属的水，破坏了整个生态系统，污染了供水，危及公众健康。整个阿巴拉契亚地区的煤矿排水（CMD）中溶解锰（Mn）的浓度特别高，如此高的水平可能导致神经系统疾病。生物活性石灰石处理床是处理含锰高的含金属CMD的最有前途和经济可行的方法之一。石灰石被用来提高受污染水的pH值，以促进微生物的生长，这些微生物可以（通过氧化反应）将可溶性锰转化为固体氧化锰矿物，这些矿物质随后被保留在处理床中。这些矿物质的形成有效地去除水中的锰，并产生一种作为水处理过滤器的基质，有效地去除CMD中的额外污染物，如钴、锌和镍。此时，从矿井水中成功去除锰和其他金属污染物的情况变化很大，在宾夕法尼亚州的一些系统中，锰的去除率低至20%。目前，由于对微生物群体的个体和集体活动以及生物介导的氧化锰形成的最佳条件了解不足，这些处理系统的成功受到限制。本研究将通过模拟受控实验室条件下的石灰石处理系统来解决这些知识空白，从而更好地建立最有效的生物地球化学条件，以刺激CMD处理系统中的微生物生长和随后的金属衰减。具体来说，该项目将首先确定最有效的微生物种类和营养条件（例如，有机碳和氮组成），通过纯和混合实验室培养的细菌、真菌和藻类来刺激最佳的锰氧化物形成，这些细菌、真菌和藻类之前从CMD处理系统中分离出来。然后，这些重要的营养和微生物条件将在实验室模拟处理系统中进行应用和测试，以通过复杂的微生物组合和关键微生物物种的活性进一步优化Mn的去除和沉淀效率。在整个实验过程中，将确定影响Mn去除和Mn氧化物形成的微生物种群结构和群落相互作用。还将评估生物沉淀氧化锰矿物的组成和稳定性及其去除金属污染物的功效。为清洁受污染的环境和供水制订成功和具有成本效益的办法是当务之急。该项目将回答限制生物刺激处理过程成功的关键科学问题，并优化目前在世界各地使用的低成本绿色技术，以试图清洁被矿井排水破坏的环境。从这个项目中获得的基本知识将传达给科学家、工程师、教育工作者和政府监管机构，以直接应用于目前在阿巴拉契亚地区数百个地点用于处理煤矿排水的石灰石处理系统。这个项目的一个同样重要的目标是教育后代和一般公众了解矿井排水的原因、影响和解决办法。pi将把这项研究整合到两项外展活动中，包括(1)高中科学教师实习，以帮助开发新课程，吸引STEM领域代表性不足的学生，并向他们介绍用于处理环境污染的绿色技术；(2)在国家自然历史博物馆、史密森学会、向公众宣传科学活动和产品，并为参观者提供提问和与科学家互动的机会。