Adsorptive membranes for heavy metal removal – A mini review

Water and wastewater containing heavy metals is an emerging issue in these recent years due to fast growing global population, urbanization and climate change which lead to water scarcity over the world. The local authorities and researchers have been working on finding new water sources and various treatment methods by recycling and reuse wastewater. Insoluble heavy metals can be easily removed via precipitation or membrane separation. However, removing soluble heavy metals from water and wastewater is a great challenge. The removal of heavy metals using membrane by adsorption is a relatively new method and it has received considerable attention recently. A number of researches have investigated on adsorptive membrane fabrication and their applications on specific heavy metals adsorption such as Pb, Zn and Cu. This paper reviews the adsorption mechanisms of heavy metals on membranes and several types of adsorbents incorporated in the membranes (carbon source, metal oxides and natural materials) for adsorption enhancement.