Bioremediation techniques for the treatment of mine tailings: A review

Abstract

Mine tailings (MTs) are the materials dumped on a mining site after mineral extraction, containing scattered traces of residual minerals, dug-up soils, and a disturbed ecosystem. Abandoned and untreated MT can pose threats to the surrounding ecosystem due to the presence of various primary and secondary toxic components, such as organic substances [PAH (polycyclic aromatic hydrocarbons), phenolics] and inorganic materials (sulfur, cyanide), metals and metalloids. All these pollutants originate from nature, and there is a possibility to remedy the problems generated from them. Conventional physical-chemical and biological techniques are often considered for treating the polluted environment and are recognized as having great efficiency. Physicochemical processes, such as incineration, and soil washing with solvents, encounter limitations of cost-effectiveness associated with further environmental concerns. The advantages accompanying bioremediation, the alternative to physicochemical treatment, are its cost-effectiveness, its environmentally benign nature, and complete mineralization of pollutants, instead of the generation of secondary toxic intermediates as in the case of the physicochemical process, make it more attractive for dealing with MT. This manuscript emphasizes use of basic treatment techniques and bioremediation mechanisms for dealing with pollutants from MT that target the revival of nature by utilizing natural agents, plants (phytoremediation), bacteria, fungi, and algae.