Elimination of Pollutants Through Nanomaterials
Covering a broad spectrum of science, nanotechnology is defined by the minute size (nanoscale) of the materials involved in its study and processes. A nanometer equals one-millionth of a millimeter. In contrast to materials operating at a macro- or microscale, the same materials at a nanoscale display different physical properties and can be used to control pollution, according to the Science and Development Network.
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Nanofiltration
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Nanofiltration membranes are widely used technology that not only treat and soften contaminated water but also extract salts and other pollutants. The tiny membranes form a physical blockade, trapping particles that are too large to pass through their pores. Novel types of nanoporous materials outperform traditional filters. A South African study has put forth that briny groundwater can be made into drinking water through the use of nanofiltration membranes. Carbon nanotube filters are better at eliminating viruses and bacteria than their conventional counterparts, reports the Science and Development Network.
Nanocatalysts
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Due to their extremely small size and yet larger surface area in comparison to bulk particles, nanocatalysts exhibit enhanced catalytic properties and can purify contaminated water. As opposed to simply shifting pollutants to another location, nanocatalysts are able to chemically break down pollutants. For developing countries that grapple with inefficient technologies or are unable to afford costly technologies, nanocatalysts offer an effective alternative to water treatment. In the past 10 years, scientists have discovered titanium dioxide (TiO2) nanoparticles can be used as catalysts for both organic and inorganic pollutants. For example, titanium dioxide nanoparticles, when exposed to ultraviolet light, can remove organic wastes from water, reports the UCLA School of Public Health.
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Magnetic Nanoparticles
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In contrast to non-magnetic nanoparticles, magnetic nanoparticles not only bind with chemicals but can be removed from water by employing a magnetic field. For example, in water sanitization, magnetic nanoparticles will bind with oil or arsenic. The resulting compounds are then extracted with a magnet. In some processes, these same nanoparticles can be separated from harmful compounds after water treatment and recycled. For example, scientists at Rice University are using magnetic "nanorust" to extract arsenic from water, reports the Science Development Network. Because nanorust has such a large surface area, it can remove 100 times more arsenic than comparable materials.
Sensors
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In addition to water sanitization, nanoparticles are being used to detect contaminants in water. By combining micro and nanofabrication, scientists have developed tiny, precise and easily transported sensors that can detect single-celled biochemical or chemical materials in water. Scientists at Pennsylvania State University are employing nanowires on a silicon chip to distinguish arsenic in water, reports the Science Development Network.
Nanofibers
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In 2007, the Royal Society gave developers of a pollution control technology that employs nanofibers to trap CO2 the Brian Mercer Award for Innovation, according to Nanowerk News. Nano-porous fibers consist of minute pores and materials that capture and remove hydrocarbons and other greenhouse gases from the air flow in a wide spectrum of industrial processes.
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References
- Nanowerk: Pollution control technology using nanofibers to trap CO2
- UCLA School of Public Health: Nanomaterials and water purification
- Wiley-VCH: Pollution Prevention and Treatment Using Nanotechnology
- AZoMaterials: Nanomaterials and Their Applications
- Science and Development Network: Nanotechnology for clean water
