About one billion people in the world don’t have access to clean water since most of the water sources are contaminated. As world population increases, so does industrialization and urbanization. These socioeconomic developments generate an escalating demand for water, which causes all kinds of environmental and social dilemmas such as contamination of water resources with waste water. Developing countries most commonly deal with water-borne infectious diseases that are resistant to antibiotics. In order to secure water resources water reuse is becoming more viable. One of the concerns with water reuse is the contamination with chemicals, bacteria and other pollutants. Researchers are investigating the use of nano-particles as a useful method for water purification and cost and energy reduction.
Nanotechnology can greatly contribute to better water quality and ensure its availability by using sophisticated and effective filtration materials. Some materials being evaluated for this function are carbon-nanotubes, metal-oxide nano-particles, zeolites and dendrimers. The use of carbon nanotubes or fluorine in filter membranes may increase their potential and reduce process time and cost. These carbon containing membranes make water molecules move faster trough the filter and it doesn’t plug up fast. Thereby these filters can be cleaned less frequently than conventional ones.
Other uses for nano-particles are for metal removal and disinfection of water sources. Nano materials are highly reactive, have a large surface area compared to their mass and can easily capture other particles. Metal-oxide nano-particles (like titanium dioxide and silver) are highly effective in decomposing micro-pollutants and bacteria. Computer manufacturing leader IBM, along with other researchers is evaluating the use of materials usually intended for the production of computer chips, for assisting in contaminant removal.
Using nanotechnology for improving water supply and water recycling may have various benefits. Nano-particles can be fabricated to reduce odor, reduce biological and chemical oxygen demand, neutralize pH, improve water clarity and aid in chemical spills (like oil, diesel or gasoline) in both water and soil. Nano- materials also have the ability to perform over wide ranges of temperature and pH levels.
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N. Savage, M. Diallo (2005). “Nanomaterials and water purification: Opportunities and challenges”. Journal of Nanoparticle Research 7:331-342.