Phytoextraction of high value elements and contaminants from mining and mineral wastes: opportunities and limitations

• Published in: Plant and soil 2020-04, Vol.449 (1-2), p.11-37
• Main Authors: Corzo Remigio, Amelia, Chaney, Rufus L., Baker, Alan J. M., Edraki, Mansour, Erskine, Peter D., Echevarria, Guillaume, van der Ent, Antony
• Format: Article
• Language: English
• Subjects: Arsenic; Base metal; Biomedical and Life Sciences; Cadmium; Case studies; Cobalt; Concentrates (ores); Contaminants; Contaminated land; Ecology; Economics; Environmental Sciences; Heavy metals; Land pollution; Life Sciences; Metal concentrations; Metalloids; Mine tailings; Mine wastes; Mineral industry; Minerals; Mining; Mining industry; Plant Physiology; Plant Sciences; Review Article; Rhenium; Selenium; Shoots; Soil Science & Conservation; Substrates; Thallium; Wastes
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-020-04487-3

Background Phytoextraction is an in situ technique that can be applied to minerals and mining wastes using hyperaccumulator plants to purposely bio-concentrate high levels of metals or metalloids into their shoots in order to remove them from the substrate, while achieving monetary gain. Phytoextraction can be applied to a limited number of elements depending on the existence of hyperaccumulator plants with suitable characteristics. Although phytoextraction has been trialled in experimental settings, it requires testing at field scale to assess commercial broad-scale potential. Scope The novelty and purported environmental benefits of phytoextraction have attracted substantial scientific inquiry. The main limitation of phytoextraction with hyperaccumulators is the number of suitable plants with a high accumulation capacity for a target element. We outline the main considerations for applying phytoextraction using selected elemental case studies in which key characteristics of the element, hyperaccumulation and economic considerations are evaluated. Conclusions The metals cobalt, cadmium, thallium and rhenium and the metalloids arsenic and selenium are present in many types of minerals wastes, especially base metal mining tailings, at concentrations amenable for economic phytoextraction. Phytoextraction should focus on the most toxic elements (arsenic, cadmium, and thallium) or especially valuable elements (selenium, cobalt, and rhenium). The value proposition is in the clean-up of contaminated land in the case of toxic elements, whereas it is in the ‘bio-ore’ generated by the process in the case of valuable elements.