ALGAE-BASED HEAVY METAL REMEDIATION IN ACID MINE DRAINAGE: A REVIEW

The production of acid mine drainage (AMD) is among the factors responsible for much of the degradation of water and soil resources and the disruption of biodiversity in the environment. Several studies have shown that organisms (either macro or micro) present at sites contaminated with AMD have the potential to bioaccumulate heavy metals and hence stimulate their application in bioremediation processes. Algal strains are not an exception to those organisms found in AMD. This review was aimed at examining the heavy metal remediation of AMD using algae, remediation properties of algae and different algal-based methods used in heavy metal remediation of AMD. Algal strains such as Spirulina sp., Chlorella spp., Scenedesmus spp., Cladophora spp., Oscillatoria spp., Anabaena spp. and Phaeodactylum tricornutum act as "hyper-accumulators" and "hyper-adsorbents" with a high selectivity for different elements from AMD. However, algae-based methods of abating AMD are not the ultimate solution to the problem and there is room for more studies. The current study suggests further attention to phycoremediation individually and synergistically with sulphate-reducing bacteria.