Keeping Mine Water Clean

In order to render mine water a whole lot less toxic, the key could be letting a fungus bloom. Some fungi produce a superoxide when they grow, which is instrumental in cleaning up polluting metals. This superoxide reacts with locally available Magnesium(II), and is oxidized to Mn(III) or Mn(IV), which in turn suck up the likes of arsenic, cadmium, and cobalt.