Nanotechnology is among the most revolutionary technologies in the world. The term nanotechnology describes a range of technologies performed on a nanometer scale with widespread applications as an enabling technology in various industries. Unlike other technologies, which have often sprung directly from a particular scientific discipline, nanotechnology spans a wide spectrum of science. Nanotechnology encompasses the production and application of physical, chemical, and biological systems at scales ranging from individual atoms or molecules to around 100 nanometers, as well as the integration of the resulting nanostructures into larger systems. The principal way nanotechnologies might help alleviate water problems is by solving the technical challenges that removing water contaminants including bacteria, viruses, toxic metals, pesticides and salts. Numerous scientists’ claims that nanotechnologies offer more affordable, effective, efficient and durable ways of achieving specific nanoparticles for water treatment will allow manufacturer to prepare less toxic particles using classical methods.