Passive and active treatment of contaminated mine water

采矿业是加拿大强大经济的重要贡献者，但产生大量废物，并使用水和能源等关键资源。负责任地管理受污染的水是采矿业面临的一项重大挑战，可以确定三个优先事项：1)开发可持续处理技术；2)处理后残留盐度控制；3)从产生的污泥中安全处理和回收潜在的经济元素。这一逐步创新的5年项目将围绕矿山污水的被动处理和主动处理进行研究，并有三个长期目标：1)利用现场可获得的材料，提高矿山污水在寒冷气候和高盐度条件下的被动处理性能，以降低运输成本和修复的足迹影响；O2)改性天然材料和工业残留物在矿山水的预防和被动/主动处理中的性能和价值优化；O3)提高对矿井水中稀土元素的认识和主动处理效率。在被动处理方面，通过O1和O2（部分）规划了两个项目：Project 1.1 [PhD1， UG1]寒冷气候下盐矿废水被动处理性能；项目1.2 [MSc1]改性材料改进剂控制矿井水质量的长效效果。项目1.1将评估泥炭（未经处理或经过物理、化学或热活化）和酸性矿山排水处理污泥在过滤后的尾矿中进行低温孔隙水抛光的性能。在项目1.2中，研究将集中于使用改性白云石和木灰作为改良剂来控制矿井排水质量。在活性处理方面，通过O2（部分）和O3，规划了另外两个项目：项目2.1 [PhD2， UG2]处理预处理矿山废水中氨氮（氨氮）和残余金属及副产物潜力增值；项目2.2高岭土对矿井水中[MSc2]稀土元素的处理和回收。项目2.1将侧重于利用天然沸石或木灰沸石去除模拟和实际矿井废水中的NH3-N和残余金属，并进行N同位素平衡。最后，项目2.2将侧重于在参数研究中利用高岭土通过吸附和潜在回收去除稀土元素（商品和污染物），初步测试证明高岭土是有效的。因此，目前的5年研究计划将允许在以下方面发展有用的知识：现场可用或改性材料的使用、残留盐度产生的限制、矿井水处理过程中产生的受污染固体的潜在增值，以及受矿井水影响的自然水质。鉴于加拿大北部敏感地区采矿的发展日益增加，这项研究项目的附带利益对于保持加拿大在可持续采矿发展方面的全球领导地位至关重要。

Mining industry is essential contributor to a strong Canadian economy, but produces large volumes of waste, and uses critical resources such as water and energy. Responsible management of contaminated water is a major challenge in mining and three priorities can be identified: 1) development of sustainable treatment technologies; 2) control of the residual salinity after treatment; 3) safe handling and the recovery of potential economical elements from the sludge produced. The research proposed in this incrementally innovative 5-year program will be centered on passive and active treatment of mine effluents, with three long-term objectives: O1) Improve the performance of passive treatment for mine effluents, in cold climate and at high salinity, using on-site available materials, to reduce transportation costs and footprint impact of rehabilitation; O2) Optimize the performance and valorization of modified natural materials and industrial residues in the prevention and passive/active treatment of mine water; O3) Improve the knowledge and active treatment efficiency of REE (rare earth elements) in mine water. In passive treatment, through O1 and O2 (partially), two projects are planned: Project 1.1 [PhD1, UG1] Performance of passive treatment for saline mine effluents in cold climate; Project 1.2 [MSc1] Long-term efficiency of modified materials as amendment to control mine drainage quality. Project 1.1 will evaluate the performance of peat (raw or after physical, chemical or thermal activation) and of acid mine drainage treatment sludge in pore water polishing from filtered tailings, at low temperature. In project 1.2 the research will focus on the use of modified dolomite and wood ash as amendments to control mine drainage quality. In active treatment, through O2 (partially) and O3, two other projects are planned: Project 2.1 [PhD2, UG2] Treatment of NH3-N (ammonia nitrogen) and residual metals in pre-treated mine effluents and by-products potential valorization; Project 2.2 [MSc2] REE treatment and recovery from mine water using kaolin. Project 2.1 will focus on NH3-N and residual metals removal in mock and actual mine effluents, using natural or wood ash-based zeolites, and an N isotopic balance. Finally, the project 2.2 will focus on REE removal (commodities and contaminants) by sorption and potential recovery, in a parametric study, using kaolin, which proved efficient in preliminary testing. Therefore, the present 5-year research program will allow useful knowledge development on the use of on-site available or modified materials, on the limitation of residual salinity creation, on the potential valorization of contaminated solids generated during mine water treatment, and on the natural water quality as influenced by mine water. Given the increased development of mining in sensitive areas of northern Canada, the spin-offs from this research project will be critical in maintaining Canada as a global leader in sustainable mining development.