Treatment of zinc-rich acid mine water in low residence time bioreactors incorporating waste shells and methanol dosing

► Continuous flow studies assess the efficacy of bioreactor substrates for passive mine water treatment. ► Combination of waste shells, manure and sewage sludge effective for >400 days in removing Pb, Cu and Fe. ► Sustained Zn removal in low residence time systems required methanol dosing. ► Alkalinity generation better in waste shells than traditional limestone clasts. ► Column tests inform design of pilot field systems.