A review of treatment technologies for the mitigation of the toxic environmental effects of acid mine drainage (AMD)

Sustainable resolutions for environmental threat of the acid mine drainage.

Removal and potential recovery of rare earth elements from mine water

A critical review of prevention, treatment, reuse, and resource recovery from acid mine drainage

The replacement of traditional and non-renewable resources by shifting towards renewable-based strategies is a strategy implemented by the European Union for a circular economy-based society. Among the various methods to produce renewable biofuels, hydrothermal carbonization is promising in terms of waste management. This technology involves thermochemical treatment of wastes at lower emperatures than other common thermal treatments such as pyrolysis or gasification. Here we review hydrothermal carbonization for managing a wide variety of biomass–wastes and obtaining value-added products. Three types of products are obtained: gases, liquids and solids. The solid carbonized product is the main product, which can be used for many applications, highlighting its use as substitute for fossil coal. Nonetheless, actual commercial plants hardly reach profitability by considering only the solid products. Therefore, this review focus on the integration of other processes. For instance, anaerobic digestion, catalytic conversion of gaseous streams and membrane technology for liquid concentration appear as the most interesting options to valorize all the products generated during hydrothermal carbonization.

Hydrothermal carbonization of biomass and waste: A review

Acid mine drainage induced by the mining industry causes environmental and economic issues. Acid mine drainage contains mainly metals such as Fe, Al, Cu, Ca, Mg, Mn and Zn. Preventing the formation of acid mine drainage has not been found feasible. As a consequence, remediation treatments have been developed during the last years to remove metals and obtain high-quality water, which may be reused. We review here several treatment options such as selective metal precipitation, adsorption, electrochemical processes and membrane processes. Adsorption is the most employed commercially since it can recover 99% of the metals. Membrane processes are promising according to lab-scale results, notably because high-quality water is obtained. Further research is necessary to implement combination of technologies, e.g., adsorption membrane, at larger scales, as well as to obtain more valuable products that can balance the overall economy for the mining industry.

Sara Vázquez

Papers

Remediation of acid mine drainage