Recent advances in activated carbon modification techniques for enhanced heavy metal adsorption

The contamination of water with heavy metals is a global issue. Its water solubility and non-degradability nature convert it into a potential threat to human health as well as flora and fauna. Several methods have been applied for heavy metal removal from water using a different mechanism, which differs in specification and removal efficacy. Activated carbon has recently attracted the attention of wastewater treatment industries because of its significantly high adsorption capacity against heavy metals. The large surface area, suitable surface functional groups, and appropriate pore diameter make activated carbon a potential adsorbent. Significant advances have been recently reported to modify the activated carbon using physical, chemical, organic, and inorganic loading techniques to improve the adsorption performance of activated carbon. This review presents the recent advances in activated carbon preparation and modification for heavy metal removal from water. Different fabrication techniques and the mechanisms of heavy metal adsorption are also discussed in detail.