<p>The present study systematically and comprehensively reviewed different aspects of treating Acid Mine Drainage (AMD) with active treatment and waste materials. The work also critically reviews the status and the factors associated with the treatment process. Although, conventional active methods are very efficient but they are mainly associated with costly material as well as high maintenance cost which enhances the cost of entire treatment system. Waste materials such as fly ash, metallurgical slag, zero valent iron (ZVI), cement kiln dust (CKD), organic waste such as peat humic agent (PHA) and rice husk can be efficiently used for the treatment of AMD. However, efficiency of different waste material varied from each other due to the variation in their physical and chemical characteristics. The results from the investigation showed that fly ash, metallurgical slag and CKD raise the pH of acidic solution more, in comparison to ZVI and organic waste, due to their richness in lime content. Furthermore, fly ash can be efficiently converted and utilized in its other derivative such as chemically modified fly ash and zeolite. Efficiency of ZVI is hindered by the presence of higher concentration of total dissolved solids. PHA can treat AMD that is mild acidic in nature. Besides, long retention time is required for the removal of heavy metals and sulfur with organic waste and sulfate reducing bacteria (SRB). The study also potentially reviewed that metal removal from AMD varied due to composition of AMD and the characteristics of waste materials. However, waste materials demand more attention for its practical applicability in field conditions due to its richness, higher possibility for recycling and reuse, low installation cost and harmless nature towards the environment.</p>
Treatment of acid mine drainage with coal fly ash in a jet loop reactor pilot plant
