Ecofriendly Control of Mine Tailings Dust through Establishment of Biocrusts

通过建立生物结皮来环保控制尾矿粉尘

• 批准号: 2218294
• 负责人: Lianyang Zhang
• 金额: $ 38.2万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2218294&HistoricalAwards=false
• 关键词: Ecofriendly; Control; Mine; Tailings; Dust

The mining industry generates a significant amount of mine tailings, pulverized rock that remains after the valuable metal-bearing minerals have been extracted. The generated mine tailings are collected and transported in the form of a slurry or paste to large on-site impoundments. The tailings impoundments range in size from a few hundred to a few thousand acres. Water in the tailing slurry is recovered for reuse and the solid material is left for long-term storage. In arid and semiarid areas such as the regions of the southwestern United States, mine tailings can become wind borne and result in particulate emissions. The environmental impacts of this dust include reducing visibility, degrading air quality, and contaminating surface water and soils. Although different methods have been attempted for mine tailing dust control, they all have limitations. There is an urgent need for developing ecofriendly and cost-effective methods for mine tailing dust control. The overarching goal of this research is to investigate the effects of factors on the establishment of biocrusts (specialized organisms covering the surface) on mine tailings and evaluate the physical, chemical, mechanical, and environmental behavior of biocrust-stabilized mine tailings at multiple scales. Successful completion of this project will benefit society through the development of new fundamental knowledge that could lead to an ecofriendly and cost-effective dust control technology for addressing the adverse effects of mine tailing dust. Further benefits to society will be achieved through outreach and educational activities including the mentoring and training of one graduate student for the duration of the project and two undergraduate students per year at the University of Arizona.Mine tailings in arid and semiarid areas are prone to wind erosion and the associated contaminants can be dispersed throughout the environment as dust particles, causing serious deleterious effects on the environment and human health. The overall goal of this research is to develop an ecofriendly and cost-effective method for sustainable mine tailing dust control. To achieve this goal, the proposed research takes a multi-scale and multi-disciplinary approach and will 1) conduct systematic laboratory studies to define and optimize the parameters for culturing cyanobacteria and growing biocrusts on mine tailings, 2) characterize the biocrust-stabilized mine tailings to relate the macro-scale behavior to the micro/nano-scale characteristics and understand the underlying mechanism of stabilization and dust control based on biocrust establishment, and 3) demonstrate and validate the integrated biopolymer stabilization and biocrust establishment technology dust control and other environmental benefits by conducting field tests. The proposed technology for ecofriendly mine tailing dust control is based on integrated biopolymer stabilization and biocrust establishment and may lead to a new paradigm for dust control and environmental protection. The study systematically investigates the effect of different factors on the establishment of biocrusts on mine tailings and evaluates the physical, chemical, mechanical, and environmental behavior of biocrust-stabilized mine tailings at multiple scales. Successful completion of this project will elucidate the fundamental science on biocrust-mine tailing interactions and lead to better understanding of the underlying mechanism of stabilization and dust control based on integrated biopolymer stabilization and biocrust establishment. Additional education and outreach activities include a summer camp for K-12 students through the Summer Engineering Academy at the University of Arizona, development, and display of an exhibit at Biosphere 2, and mentoring of undergraduate and graduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

采矿业产生大量的尾矿，即在提取有价值的含金属矿物后留下的粉状岩石。所产生的尾矿以泥浆或糊状物的形式收集并运输到大型现场蓄水池。尾矿库的面积从几百英亩到几千英亩不等。尾矿浆中的水被回收再利用，固体材料被长期储存。在干旱和半干旱地区，如美国西南部地区，尾矿可以成为风载，并导致颗粒物排放。这些粉尘对环境的影响包括降低能见度、降低空气质量以及污染地表水和土壤。虽然人们尝试了不同的方法来治理尾矿粉尘，但它们都有局限性。因此，迫切需要开发环境友好、经济有效的尾矿粉尘治理方法。本研究的总体目标是调查因素对尾矿上生物结壳（覆盖表面的专门生物）建立的影响，并在多个尺度上评估生物结壳稳定尾矿的物理，化学，机械和环境行为。该项目的成功完成将通过开发新的基础知识造福社会，这些知识可能导致一种生态友好和具有成本效益的粉尘控制技术，以解决矿山尾矿粉尘的不利影响。通过推广和教育活动，包括在项目期间指导和培训一名研究生，以及每年在亚利桑那大学指导和培训两名本科生，将进一步造福社会。干旱和半干旱地区的尾矿易受风蚀，相关污染物可作为灰尘颗粒散布在整个环境中，对环境和人类健康造成严重的有害影响。本研究的总体目标是开发一种生态友好和经济有效的方法，可持续的矿山尾矿粉尘控制。为了实现这一目标，拟议的研究采取多尺度和多学科的方法，并将1）进行系统的实验室研究，以确定和优化培养蓝藻和在尾矿上生长生物结壳的参数，2）表征生物结壳稳定的尾矿，以将宏观尺度行为与微/纳米尺度行为相关联。规模的特点，并了解稳定和粉尘控制的基础上建立生物结壳的基本机制，以及3）通过进行现场试验来证明和验证集成的生物聚合物稳定化和生物结壳建立技术粉尘控制和其他环境益处。提出的生态友好型矿山尾矿粉尘控制技术是基于集成的生物聚合物稳定和生物结壳的建立，并可能导致粉尘控制和环境保护的新范式。系统研究了不同因素对尾矿生物结壳形成的影响，并在多尺度下评价了生物结壳稳定尾矿的物理、化学、力学和环境行为。该项目的成功完成将阐明生物结壳-尾矿相互作用的基础科学，并导致更好地理解基于综合生物聚合物稳定和生物结壳建立的稳定和粉尘控制的潜在机制。其他教育和推广活动包括通过亚利桑那大学夏季工程学院为K-12学生举办夏令营，在生物圈2号开发和展示展览，以及指导本科生和研究生。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。