The contamination of water is a global concern that is affecting millions of people, causing different diseases, such as diarrhea, typhoid fever, and hepatitis. A potential remedy for these problems is provided by nanomembranes. Traditional water restoration techniques have some drawbacks, viz. exorbitant prices, detrimental effects on the ecosystem, and an incapacity to get rid of recently discovered pollutants. However, nanomembranes provide benefits over conventional techniques, including decreased environmental impact, cost-effectiveness, and flexibility to change contaminants. Nowadays, several membranes are utilized to purify water incorporating 2D materials, such as graphene, MOFs, zeolite, TMDCs, MXenes, C3N4, and hBN. This chapter provides insightful information on developing the next generation of membranes for effective, scalable, and affordable water filtration for readers interested in this exciting study area. Furthermore, a detailed analysis of nanomembrane synthesis utilizing various nanomaterials (NMs), such as metal oxides, metallic materials, and metal-organic frameworks which has further enhanced the membrane performance by improving mechanical strength, adsorption capacities, and separation efficacy. Moreover, the production processes for these membranes are conducted, emphasizing both their benefits and drawbacks are also discussed. Nevertheless, there are drawbacks to employing nanomembranes in water filtration, including scaling, fouling, regeneration, and possible negative environmental consequences. Furthermore, the chapter undertakes a comprehensive examination that covers the background, technical applications, scalable, difficulties, constraints, possible applications, and reusability of these NMs.