Water Filtration:
- Water purification using nanotechnology exploits nanoscopic materials such as carbon nanotubes and alumina fibers for nanofiltration
- it also utilizes the existence of nanoscopic pores in zeolite filtration membranes, as well as nanocatalysts and magnetic nanoparticles
- Nanosensors, such as those based on titanium oxide nanowires or palladium nanoparticles are used for analytical detection of contaminants in water samples.
- It can be used for removal of sediments, chemical effluents, charged particles, bacteria and other pathogens.
- "The main advantages of using nanofilters, as opposed to conventional systems, are that less pressure is required to pass water across the filter, they are more efficient, and they have incredibly large surface areas and can be more easily cleaned by back-flushing compared with conventional methods," - Alpana Mahapatra and colleagues Farida Valli and Karishma Tijoriwala
- carbon nanotube membranes can remove almost all kinds of water contaminants including turbidity, oil, bacteria, viruses and organic contaminants.
- Although their pores are significantly smaller carbon nanotubes have shown to have an equal or a faster flow rate as compared to larger pores, possibly because of the smooth interior of the nanotubes.
- Nanofibrous alumina filters and other nanofiber materials also remove negatively charged contaminants such as viruses, bacteria, and organic and inorganic colloids at a faster rate than conventional filters.
- "Nanotechnology for water purification" in International Journal of Nuclear Desalination, 2010 ^ https://www.eurekalert.org/pub_releases/2010-07/ip-nfw072810.php
- In the near future, it has been estimated that average water supply per person will drop by a factor of one third, which will result in the avoidable premature death of millions of people
- Conventional desalination technologies like reverse osmosis membranes are being used but these are costly due to the large amount of energy required.
- Nanotechnology has played a very important role in developing a number of low-energy alternatives, among which three are most promising. (i) protein-polymer biomimetic membranes, (ii) aligned-carbon nanotube membranes and (iii) thin film nanocomposite membranes
- These technologies have shown up to 1000 times better desalination efficiencies than RO, as these have high water permeability due to the presence of carbon nanotube membranes in their structure
- Some of these membranes are involved in the integration of other processes like disinfection, deodorizing, de-fouling and self-cleaning.