Comparison of Fe and Mn removal using treatment agents for acid mine drainage.

This study investigated the potential for utilizing six treatment agents (two limestones, sand, starfish, black shale, and concrete as treatment agents for acid mine drainage (AMD) wastewater. These materials, with a high capacity for heavy metals, can be obtained and employed as alternative low-cost limiting substitutes. For investigating the neutralization capacity, the change in pH, Eh, and EC as a function of time was quantified. Of the treatment agents, concrete showed the highest neutralization efficiency for AMD and maintained the pH value above 11. Results of column studies demonstrated that the removal rate of Fe and Mn by the tested agents was influenced by their chemical compositions. The experimental results of desorption revealed that when adsorption or precipitation occurs, there were no significant releases from the adsorbing agents. In this study, the results suggest that concrete can be used successfully in the treatment of acid mine drainages with mixed metal-contaminated wastes.