Supplying Clean Water Globally
Emulating Biology through Nanotechnology to Purify Water
Stephen L. Gillett, Ph.D.
Dept. of Geological Sciences
Mackay School of Mines
University of Nevada
http://www.foresight.org/SrAssoc/BioGillett.html
Clean water—for humans and animals, for agriculture, for industry—is a fundamental necessity. Billions of people worldwide, however, do not have access to clean drinking water. Even in the industrialized countries, with their enormously expensive water distribution and purification infrastructures, maintaining the purity of water supplies remains a pressing issue, particularly with the pressure to remediate pollution legacies accumulated over decades.
Contrary to popular belief, purifying water, even including desalination, is not intrinsically an energy-expensive problem. Biosystems selectively separate solutes from water at low concentrations with much less fuss than current technology; kidneys are an example. Supplying pure water is also not intrinsically a capital-intensive problem. With better technology, decentralized purification is not only practical but considerably cheaper. Indeed, in industrialized countries pollution control is already becoming decentralized, due to restrictions on discharge concentrations of toxins.
Nanotechnology promises to considerably improve decentralized water purification systems, in emulation of biological capabilities. Better control of nanoscale fabrication will lead to large gains in efficiency and longevity in such areas as:
- Membrane technologies such as reverse osmosis and electrodialysis (both much used in pollution control and desalination);
- Adsorption processes such as ion exchange;
- Advanced oxidative technologies (e.g., photo-oxidation) for disinfection;
- Cheaper synthesis of compounds for the selective extraction of highly toxic solutes (e.g., mercury).
Moreover, "switchable" adsorbing materials, which could be eluted merely by an external "trigger" such as light or electricity, will be a vast improvement over current versions whose regeneration typically requires extreme chemical measures (e.g., flushing with brine) that lead to even greater amounts of wastewater. Such materials, however, will require nanoscale design and fabrication.
Some representative links:
Governments and NGOs:
World Water Assessment Programme (WWAP)| The UN World Water Development Report (WWDR)
USGS—Water Resources of the United States
Environment Canada's Green Lane
Water Quality Association
American Water Works Association
SIWI — Stockholm International Water Institute
WaterGenius.com — Now a Complete Search Engine of Water Industry
Commercial companies:
Global Water Intelligence
Reverse Osmosis and Ultrafiltration
An extant "pocket" water disinfector:
MSR - Mountain Safety Research : Water Filters : MIOX® Purifier
Investment implications:
Blue Gold
The Case for Investing in Water Industry Stocks 2005
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