Impact of climate change on acid mine drainage generation and contaminant transport in water ecosystems of semi-arid and arid mining areas

• Oxidation of sulfide minerals resulting in acid mine drainage, low pH and toxic metals.
• Geologic and geochemical controls on acid mine drainage chemistry.
• Reactive transport models to simulate the evolution of AMD and groundwater.
• Drawbacks, limitations and benefits of reactive transport models.
• Impact of climate change on geochemical reactions and mining activities.

Disposal of untreated and treated mining wastes and tailings exerts a significant threat and hazard for environmental contamination including groundwater, surface water, wetlands, land, food chain and animals. In order to facilitate remediation techniques, it is important to understand the oxidation of sulfidic minerals, and the hydrolysis of the oxidation products that result in production of acid mine drainage (AMD), toxic metals, low pH, SO42- and Fe. This review has summarized the impacts of climate change on geochemical reactions, AMD generation, and water quality in semi-arid/arid mining environments. Besides this, the study included the effects of hydrological, seasonal and climate change on composition of AMD, contaminant transport in watersheds and restoration of mining sites. Different models have different types of limitations and benefits that control their adaptability and suitability of application in various mining environments. This review has made a comparative discussion of a few most potential and widely used reactive transport models that can be applied to simulate the effect of climate change on sulfide oxidation and AMD production from mining waste, and contaminant transport in surface and groundwater systems.