
Nanotechnology could help solve the world’s water problems-all it needs is funding.
August 15, 2005 Print Issue
The problem-a lack of safe, clean, and affordable water-is enormous. The solution could be quite small.
Traditional remedies, such as filters, desalination, and water recovery systems, are limited in scope because they cost too much, are inefficient, require lots of maintenance, or use too much energy.
Enter nanotechnology. The science of the small has the potential to tilt the economic balance of many existing water-related technologies in favor of large-scale use, says Tim Harper, CEO of London-based Cientifica, a consultancy specializing in nanotechnology.
Nanotechnology is not likely to provide much in the way of radical new technologies for desalination, purification, or wastewater recovery.
But adapting existing nanotechnologies for use in the water industry could provide huge benefits, argues Mr. Harper, author of a soon-to-be published white paper called “NanoWater.”
Scientists have researched the possible water applications of nanotechnology for years. Now, the technologies need to be turned into actual products, says Mr. Harper. “While we in the developed world sit around and talk about the pros and cons, there are people in the developing world who are dying of waterborne diseases,” he says.
The technology and the business case are there, says Mr. Harper; they just need capital to get going. Mr. Harper is behind a global organization called Nanowater.org, which acts as a bridge between water remediation companies and nanotech firms. “If we could get funding now, we could have initial results in six months, field trials in 12 months to 18 months, and be saving lives within two to three years,” he says. “Nanotechnology is developed, but not for water.”
Nanoscale “needles” that puncture bacteria, already being used in footwear to fight odors, could potentially be applied to water-treatment applications, says Mr. Harper. So could nanoparticulate silver, which is currently used in wound dressings to fight infection.
Then there are nanofibers, which are already used in many industrial applications. NASA is evaluating ceramic nanofibers for water purification in space because of their ability to increase throughput and reduce clogging compared to traditional filtration methods.
Here on Earth, though, nanotechnology is just starting to show what it can do for water.
The use of nanofiltration, which is common in most industrial filtration processes, is the first application to trickle into the water sector. KX Industries, a privately held company in Orange, Connecticut, that produces consumer and light-industrial water filters, is producing nanoscale filters that will screen out items as small as bacteria and viruses for the specific purpose of eradicating waterborne disease, one of the main killers in developing countries. Switzerland’s Membratec and Germany’s BASF are also applying nanotechnologies to filtration.
But in other segments of water treatment, nanotechnology’s potential has yet to be truly leveraged. Take the case of desalination, an area where nanotechnology could cut costs, save energy, and improve the lifetime and efficiency of membranes. Today, seawater is most often turned into drinking water through a 40-year-old process called reverse osmosis, which is slow, expensive, and energy intensive.
One way of improving the process is using a modern-day version of forward osmosis. Hydration Technologies of Albany, Oregon, has developed a semi-permeable membrane that acts as a molecular sieve, allowing water to pass through while rejecting impurities such as viruses, anthrax spores, e.Coli bacteria, heavy metals, and other health threats. Today the technology is used to clean up industrial water and in the production of some food concentrates.
Another potential application is sensitive-sensor technology, which involves the use of carbon nanotubes, nanowires, and micro- and nanoscale cantilevers to detect contaminants. These sensors could effectively and affordably protect against biowarfare through contamination of water supplies. Nanosight in the United Kingdom has a system that can detect waterborne nanoparticles and viruses in real time.
Nanotech can also help tackle decontamination of groundwater from industrial and natural sources. Taiwan Surfactant is developing a surface-modified gel designed to selectively absorb heavy metal ions from wastewater using a novel nanopore structure.
Still, most nanotech companies aren’t yet exploring water treatment applications, and research labs suffer from lack of funding, says Mr. Harper. In 2003 Cientifica, the Peres Center for Peace, and the Israeli Nanotechnology Trust hatched a plan to use an Israeli-based nanotechnology water initiative to provide access to clean, affordable water for domestic, industrial, and agricultural use. At the same time, the project is attempting to repair the effects of large-scale desalination and excessive withdrawal of water from aquifers. Israel plans to generate half of its urban water supplies through desalination by 2008. If nanotechnology can make the process cheaper and more efficient, it could have a large impact.
Field trials are important for these technologies, says Mr. Harper, because like any other business sector, the water industry is likely to adopt nanotechnologies once it sees that costs can be reduced through lower maintenance and better efficiency.
If nanotech really can bring down the cost of water treatment or desalination, clean water could be within the grasp of a larger portion of the world. And that will be no small feat.
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