Importance of Capping Material Properties in Remediation of Mine Tailings

摘要(项目5：Maier，Neilson，Babst-Kostecka，Rasmussen) 矿场和冶炼厂附近土壤中的微量元素污染对 地球上的人类和环境。重建尾矿植被，尽量减少尾矿的扩散 通过风或地下水产生的污染物(即植物修复)是一种很有前途的“绿色”和低成本的干预措施。 对有毒物质的暴露。不幸的是，大多数尾矿的植物生长都受到抑制，因此有必要提供 为种子萌发和幼苗生长提供额外的健康基质。目前的做法是安装 在植物播种之前，在尾矿上覆盖一个未受污染的土壤-砾石-岩石盖子，并储存这样的 材料很容易获得，这是一种被称为“帽子和植物”的技术。然而，关键的知识差距 关于植物-土壤的相互作用，阻碍了这项技术的广泛和有效实施。这个 该项目的主要目标是确定产生持久植被覆盖的最佳策略 危险的矿场。指导性假设是盖体材料的生物物理化学性质 对于健壮的根系的发展至关重要，这些根系可以传播到底层受污染的 我的尾矿。利用创新的实验设计，该项目将开发特定的土壤健康指数 并对覆盖材料的深度和质量对根系构型的影响进行了前瞻性的评价。 被称为盐生植物(滨藜)的植物物种，用于植物修复。各种盖子材料，来自 堆积的覆盖层和邻近的天然沉积物将在连续三项温室研究中进行测试 将先进的生态、基因组和土壤健康评估结合在一起。具体地说，就是根系 将使用一种基于根管的非侵入性表型方法来监测发育情况，填充了 来自美国西南部超级基金网站的封顶材料和尾矿的不同组合。 一旦确定了最佳的土壤和植物参数，就有可能修改现有的但质量较低的 将探索以具有成本效益的方式封顶材料。这个项目将产生一种前所未有的机械性。 理解植物根系构型和功能对品质响应的同步变化 以及尾矿修复所用覆盖材料的深度。利用这一知识，具体 将制定关于修复危险地点的指导方针，并将其直接移交给采矿 行业和监管机构。因此，项目成果对经济和社会都有价值。在……里面 此外，我们的发现将作为全球模板，以缓解人类和环境健康问题 受地雷和冶炼厂影响的地区。

ABSTRACT (Project 5: Maier, Neilson, Babst-Kostecka, Rasmussen) Soil contamination with trace elements in the vicinity of mining sites and smelters poses a serious threat to humans and the environment around the globe. Revegetation of mine tailings to minimize the dispersal of pollutants via wind or ground water (i.e. phytoremediation) is a promising “green” and low-cost intervention to toxic exposures. Unfortunately, plant growth is inhibited on most tailings, making it necessary to provide additional healthy substrate for seed germination and seedling growth. The current practice is the installation of an uncontaminated soil-gravel-rock cap over the tailings prior to plant seeding, with stockpiles of such material being readily available, a technology known as “cap and plant”. However, critical knowledge gaps regarding plant-soil interactions have prevented a broad and efficient implementation of this technology. The primary objective of this project is to identify the optimal strategy for generating a lasting vegetation cover at hazardous mining sites. The guiding hypothesis is that the biophysicochemical properties of capping material are critical for the development of robust root systems that can propagate into the underlying contaminated mine tailings. Using an innovative experimental design, this project will develop specific soil health indices and assess the effects of capping material depth and quality on root system architecture in a prospective plant species known as saltbush (Atriplex lentiformis) for phytoremediation. Various capping materials from stockpiled overburden and adjacent natural deposits will be tested in three consecutive greenhouse studies that bring together advanced ecological, genomic, and soil health assessments. Specifically, root system development will be monitored using a noninvasive phenotyping method based on rhizotrons, filled with different combinations of capping material and mine tailings from Superfund sites across the US Southwest. Once the optimal soil and plant parameters are identified, possibilities to amend existing but low-quality capping material in a cost-effective way will be explored. This project will yield an unprecedented mechanistic understanding of concurrent changes in plant root system architecture and function in response to the quality and depth of capping materials used for mine tailing restoration. Capitalizing on this knowledge, specific guidelines towards the remediation of hazardous sites will be developed and directly transferred to the mining industry and regulators. As such, the project outcome will be valuable for the economy and society. In addition, our findings will serve as a global template for mitigating human and environmental health issues in areas affected by mines and smelters.