Phytostablization of Mine Tailings

尾矿的植物稳定化

• 批准号: 6901480
• 负责人: Raina M Maier
• 金额: $ 24.5万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6901480
• 关键词: environmental toxicology; environmental transport; hazardous substances; heavy metals; metal metabolism; microorganism metabolism; minings; organic chemicals; soil pollution; surfactant; toxicant interaction; waste treatment; water flow

Extensive mining activity in arid and semi-arid ecosystems of the southwestern United States has resulted in large numbers of tailings sites with elevated metal concentrations ranging between 0.1 and 5% (w/w). Many of these piles are barren or have minimal vegetation due to metal toxicity and low pH and thus are vulnerable to wind and water erosion. Phytostabilization has been proposed as an alternative economical remediation strategy to stabilize the metal contaminants and prevent human and animal exposure resulting from particle suspension (dust) in the atmosphere or dissolution in ground and surface waters. Although this strategy is receiving attention as an economical alternative to more permanent metal removal approaches, considerable research is needed to improve the feasibility of the approach as well as to systematically assess the longevity of revegetation as a remediation strategy. First, large amounts of organic matter (compost or biosolids) and water have traditionally been used for vegetation establishment, neither of which are feasible in many of the remote areas where abandoned mine tailing piles are located. Second, little research has been conducted to evaluate the time-dependent changes in physical, chemical, and biological properties of mine tailings during revegetation. Specifically, little information is available on the effect of organic matter addition, plant establishment, and the evolution of associated microbial communities on metal bioavailability, solubility and speciation. The overall goal of this project is to develop a feasible revegetation strategy for the phytostabilization of metal contaminants in mine tailing piles in arid and semi-arid ecosystems and to assess the impact of this approach on the physical, biological and chemical properties of the mine tailings. This strategy will investigate whether the specific selection of metal- and drought-tolerant native plant species in conjunction with the controlled use of a seed inoculum developed from indigenous plant growth promoting bacteria can minimize the requirement for organic matteramendment and irrigation. Second, the bioavailability, speciation, and phase distribution of contaminating metals in the plant rhizosphere will be monitored in both greenhouse and field trials in order to assess whether revegetation results in a permanent reduction in site toxicity. In addition, the effects of specific root-microbe-tailings associations on the local biogeochemistry and metal speciation of the rhizosphere will be investigated in order to identify mechanisms involved in phytostabilization and detoxification at the micrometer and submicrometer scale. Information generated from this research will define the feasibility of plant establishment as an approach to metal stabilization in mine tailings and evaluate the potential longevity of revegetation as a remediation strategy.

美国西南部的干旱和半干旱生态系统中的广泛采矿活动导致了大量金属浓度升高在0.1至5％之间的尾矿地点（w/w）。这些桩中的许多是由于金属毒性而贫瘠或植被最少，因此很容易受到风和水侵蚀的影响。已经提出了植物稳定化作为一种​​替代的经济补救策略，以稳定金属污染物并防止大气中的颗粒悬浮液（灰尘）或在地面和地表水中溶解导致人类和动物的暴露。尽管该策略正在接受关注，作为更永久金属去除方法的经济替代方案，但 需要进行大量研究以提高方法的可行性，并系统地评估植被的寿命作为一种补救策略。首先，传统上，大量有机物（堆肥或生物固体）和水用于植被建筑，在许多偏远地区都无法可行，这些地区都位于废弃的地雷尾矿堆中。其次，几乎没有进行研究来评估植被期间矿山尾矿的物理，化学和生物学特性的时间变化。具体而言，几乎没有有关有机物添加，植物建立以及相关微生物群落在金属上的演变的影响的信息 生物利用度，溶解度和物种形成。该项目的总体目的是制定可行的植被策略，用于在干旱和半干旱生态系统中矿山尾矿中金属污染物的植物固定化，并评估这种方法对矿山焊剂的物理，生物学和化学性质的影响。该策略将研究金属和耐旱的本地植物物种的特定选择以及由土著植物生长促进细菌开发的种子接种物的控制使用是否可以 最大程度地减少对有机物质仪和灌溉的要求。其次，将在温室和现场试验中监测植物根际污染金属的生物利用度，物种形成和相分布，以评估重新植被是否导致现场毒性永久降低。此外，将研究特定的根微粒尾巴关联对根际生物地球化学和金属物种形成的影响，以鉴定在微米和小计尺度上识别涉及植物稳定和排毒的机制。这项研究产生的信息将定义植物建立的可行性，作为矿山尾矿中金属稳定的一种方法，并评估植被的潜在寿命作为补救策略。