**6. Conclusion**

Waste water treatment could greatly benefit from the usage of nanoparticles. Its distinctive quality of having a large surface area can be effectively employed to remove harmful metal ions, microbial pathogens, organic, and inorganic solutes from water. Numerous kinds of nanomaterials, including zeolites, dendrimers, carbonaceous nanomaterials, and metal-containing nanoparticles, have also been shown to be effective for treating water. The chapter discusses recent developments on various nanomaterials, including molecularly imprinted polymers (MIPs), bioactive nanoparticles, molecularly structured catalytic membranes, nanosorbents, nanocatalysts, and nanosorbents with applications in waste water treatment. On both a small- scale and a large-scale, waste water may now be treated in a variety of effective ways with the help of nanotechnology.
