Acid mine drainage: Challenges and opportunities

Acid mine drainage (AMD) or acid rock drainage (ARD) is considered as one of the main pollutants of water in many countries that have historic or current mining activities. Its generation, release, mobility, and attenuation involves complex processes governed by a combination of physical, chemical, and biological factors. In general, AMD is produced by the oxidative dissolution of sulphide minerals. This paper reviews the current state-of-the-art of AMD. It critically analyses the work performed in recent years on its occurrence, effects (on human health, plant life and aquatic species), and summarizes the remediation approaches taken so far to overcome the problem of AMD. The challenges faced in tackling the remediation of AMD have also been considered. Commercially developed projects that are either in operation, being piloted or under evaluation have also been discussed. Finally, the paper speculates on future directions or opportunities that deserve exploration. (C) 2014 Elsevier Ltd. All rights reserved.