Abstract
Water is the most vital natural resource and is required for the survival of all living beings. One of the most challenging water‐related problems is water contamination due to heavy metal pollution. Heavy metals such as Zn, Cu, Pb, Hg, etc. could pose a health hazard due to their bioaccumulation in higher trophic levels of the food chain. These heavy metals have the potential to damage kidneys, lungs, central nervous system, and other important organs. Excessive levels of heavy metals can cause both acute and chronic toxicity to humans. Various techniques, for instance, flocculation, ion exchange, chemical precipitation, ultrafiltration coagulation, and many more, have been utilized for the removal of heavy metals from wastewater. However, these methods have some disadvantages such as the requirement of a large number of reagents, generation of toxic sludge, and removal of even essential metal ions. Due to these reasons, the abovementioned techniques have been replaced by immobilization and absorption on suitable sorbent methods, which are considered as the best way for the removal of heavy metals from wastewater because they cannot be degraded or destroyed. After adsorbing on sorbents, heavy metals can be easily removed and reused as raw materials. Due to the large surface area of nanomaterials, these are being used as an adsorbent for the last few years. Nanomaterials are characterized by high‐energy adsorption sites and a strong binding ability as compared with conventional adsorbents, which make them excellent adsorbents for the removal of heavy metals from wastewater. This chapter highlights the role of different types of nanomaterials (carbon and metal‐based), dendrimers, and nanocomposites in the removal of heavy metals from wastewater. The possibility of future research directions is elaborated in the chapter.