ABSTRACT
Neutral mine effluents can contain above regulated concentrations of hazardous metals and metalloids that could adversely impact the quality of receiving water bodies. To prevent, limit, and treat water pollution, extensive research has been conducted in the last two decades. Among the proposed options, the use of modified natural and residual materials seems effective and inexpensive. In the present review paper, the modified materials performance and metal removal mechanisms, their use in active and passive treatment, and their efficiency for the treatment of synthetic and real mine effluents are critically discussed. The influence factors on performance improvement following the modification are also emphasized. In summary, metal recovery and sorbent re-use could potentially diminish water treatment costs and entail responsible management of resources. Moreover, waste valorization eliminates disposal concerns while metals recovery eliminates leaching risks. However, further research is necessary to evaluate field scale performance and to complete costs evaluation.
