Use of Sulfate-Reducing and Bioelectrochemical Reactors for Metal Recovery from Mine Water

The cleaning of large volumes of metal-loaded water formed at closed and active mine sites can be a valuable resource of metals. Active treatment processes are needed to recover these metals for reuse and for better environmental protection of recipient waters. This review evaluates the mechanisms of metal removal and recovery and practical feasibility of mine water treatment in two bioreactor systems: sulfate-reducing bioreactors and bioelectrochemical reactors. The influence of treatment conditions and reactor designs on metal recovery, as well as limitations to intensify the treatment processes, are discussed. High metal removal efficiencies are reported with sulfate-reducing bioreactors, whereas metal recovery, in particular, requires reactor designs and process conditions that differ from those that are primarily applied for sulfate removal. Bioelectrochemical systems offer another route for utilizing synergistic microbial processes for metal recovery, but the performance data is still limited to laboratory- and pilot-scale experiments.