Biosorption of heavy metals in industrial effluents: A review

Abstract

Industrial processes consume large quantity of water and produce highly polluted effluents containing recalcitrant contaminants which are found to be toxic even at trace concentrations. Adsorption was reported to be effective in the removal of heavy metal ions in a solution of varied toxicity. Despite this credit, however, adsorption was faced with some setbacks ranging from adsorbent cost, incomplete removal of pollutants, and production of large volume of sludge. Microorganisms, especially microalgae play vital roles in the adsorption of metal ions due to the anionic ligands in their cell walls which attract metal cations in solution, provide best removal efficiencies by their ability to reproduce in short time, remove micropollutants at minute concentrations as well as serve as feedstock for renewable energy alternatives, after wastewater treatment.