Holistic Mechanism of Nanomaterials for Removal of Cd2+ from the Wastewater

The availability of toxic pollutants in the water is a primary obstacle to utilizing the water for drinking purposes. So, scientists are making efforts to develop cutting-edge, affordable, renewable, and environmentally friendly methods for wastewater treatment to address the water shortage challenges and protect human health from serious diseases. Many wastewater treatment techniques have been developed for water treatment, including adsorption, ion exchange, membrane separation, co-precipitation oxidation, and biochemical processes. In all these water treatment techniques, adsorption is one of the strong candidates to eliminate the Cd2+ from water because of its economic feasibility and short route. The pristine nanomaterials possessed poorer adsorption capacity than their composites. The Cd2+ adsorption capacity is in the decreasing order of the graphene oxides (GO), MXenes, multi-walled carbon nanotubes (MWCNTs), and layered double hydroxides (LDHs). This indicates that the GO is the most suitable choice for Cd2+ adsorption. In the current review, the authors discussed the performance of the MXene, graphene, GO, LDHs, and carbon nanotube (CNT)-based adsorbents. This study provides with a comparative analysis of the properties of all mentioned nanomaterials. A brief introduction of the synthesizing routes and the impact of various factors on the performance of nanomaterials have been discussed. Finally, the prospects and future challenges associated with the nanomaterials have been highlighted. In a nutshell, the porous nature, high inter-layer space, and significant specific surface area (SSA) of GO makes them an ideal candidate for the adsorption of Cd2+.