River mining – pushing the limits of passive remediation for metal recovery from acid mine drainage affected waterways

Water pollution caused by legacy mining activities can contain high concentrations of dissolved metals. My thesis investigates how we might 'mine' those metals from this polluted water to increase resource recovery and reduce negative environmental impacts. I experimented with alkaline materials to drop the concentration of metals like iron and aluminium, which can impede other systems’ performance. I then used plants and biochar to ‘mine’ the metals from the polluted water as 'river mining' systems with the hope that high-value metals would be accumulated. Unfortunately, the systems I investigated were not economically viable, but do provide good evidence for ‘river mining’.