Selection of the Optimum Active Treatment Technology for Acid Mine Drainage (AMD) Using Analytic Hierarchy Process

Abstract

The increasing number of proposed technologies for the active treatment of acid mine drainage (AMD) raises a problem for decision-makers during the selection process. Selecting the optimum treatment technology requires extensive analysis to determine the best possible treatment based on multiple and often conflicting criteria. The introduction of multi-decision criteria analysis (MCDA) provides a systematic approach to problem-solving based on both quantitative and qualitative data. In this study, analytic hierarchy process (AHP) as an MCDA tool was used to select the optimum treatment option for AMD in a local copper mining site in the Philippines. Three treatment technologies were found to be the most applicable – a combination of Conventional Lime Neutralization and Sulfidogenic Bioreactor (CLN + SB), High-Density Sludge (HDS) Process, and a combination of Two-Step Neutralization Ferrite Formation and Sulfidogenic Bioreactor (TSNFF + SB). Three criteria – technical, economic, and environmental – and eight sub-criteria were used to evaluate and analyze the three alternatives systematically. The overall ranking of the alternatives was TSNFF + SB > HDS > CLN + SB. However, sensitivity analysis showed that HDS was the most stable treatment technology when equal weights were given for each criterion. Implications from this study could provide a more reliable information for possible technology adoption to sustainably address problems on AMD which is one of the leading global environmental problems today.