Fundamentals and Practical Aspects of Acid Mine Drainage Treatment: An Overview from Mine Closure Perspective

Abstract

Acid mine drainage (AMD) is perhaps one of the most relevant challenges the mining industry has faced during the last few decades. This issue is particularly important in the scenario of mine closure where mining processes cease to be active, and the sustainability of the sites needs to be re-established. This chapter reviews the fundamentals behind the generation of AMD as well as a set of physicochemical phenomena (chemisorption, precipitation, neutralisation, etc.) usually considered by researchers to mitigate it. Mine closure conditions where human presence is seldom or frankly rare turn the wastewater treatment even more challenging as it cannot be intensive in the utilization of reagents, energy, or human resources. Therefore, from a practical standpoint, passive-like wastewater treatment strategies mimicking nature are preferred. Finally, insights with regards to the complexities behind the implementation of pilot plant and industrial wastewater treatment systems conformed by long-term reactive barriers and constructed wetlands are also revised.