Remediation of Acid Rock Drainage: Current Prevention and Mitigation Methods

Acid Rock Drainage (ARD) is recognized as a major environmental issue globally, especially for hard rock sulfide mining. Among negative impacts of ARD are threats to ecosystem health, destruction of habitats, deterioration of aquatic ecosystems, risk of groundwater contamination and public health concerns. The traditional treatment involves neutralization by adding lime or limestone and has significant environmental impacts and very short long-term performance. Besides, ARD varies significantly between mine sites, thereby other remediation strategies may provide better results than the active neutralization method.

This paper presents a review of the various techniques available and assesses biological and abiotic remediation methods currently used worldwide. The goal is to provide alternative sustainable remedies other than active neutralization with lime/limestone, contribute to ecological restoration, a recommended next step to mitigation strategies and support site-specific decision-making processes in mine sites impacted by ARD. For future research, the next steps would be: to include other emerging strategies in the comparison, especially the integration of different approaches and the use of industrial by-products, and to evaluate the potential of each technique to support site-specific ecological restoration actions. Insights from the comparison of available remediation methods, based on key factors such as costs, effectiveness and environmental impacts, may help site-specific decision-making process and inform local communities, the reclamation practitioner and environmental engineers on more sustainable remediation strategies available.