Industrial waste materials as adsorbents for the removal of As and other toxic elements from an abandoned mine spoil heap leachate: a case study in Asturias.

The purpose of this study is to determine the capacity of four industrial waste materials originate from steelmaking processes and from gas treatment at a thermal power plant to remove As and other contaminants from a leachate from the spoil heap of an abandoned mercury mine. Arsenic removal is faster in the first minutes, then increases only slightly over time reaching equilibrium in 8 hours. As removal efficiency increased with increasing adsorbent concentration. As removal efficiency was found to be 82.7%, 71%, 37.2% and 27.2% for EA, FA, HA and G, respectively, when employing 80 g/dm3 of adsorbent concentration. The main mechanism of As removal appears to be the results show that Hg and Pb are completely removed using low concentrations of adsorbents regardless of the waste material used in the treatment. FA removed more than 82% of other toxic elements such as Ni, Cu and Cd. EA is the most effective byproduct of the four employed in this study for removing pollutants, while G is the least effective. The present study shows it is possible to carry out an efficient and economical treatment of mine leachate using these byproducts.