Arizona Water Resource Vol. 18 No. 2 (Spring 2010) Authors University of Arizona. Water Resources Research Center.; Gelt, Joe; Lamberton, Melissa L.; Megdal, Sharon Publisher Water Resources Research Center, College of Agriculture, University of Arizona (Tucson, AZ) Rights Copyright © Arizona Board of Regents. The University of Arizona. Download date 27/09/2021 12:47:07 Link to Item http://hdl.handle.net/10150/325894 Volume 18, Number 2 Spring 2010 Mapping a Mythical by Joe Gelt and River Melissa L. Lamberton Maps do more than record geogra- phy; maps also reflect myths and human longings. Consider the mapping of the Buenaveventura River. The Buenaventura River was once thought to flow from the Rocky Moun- tains to the Pacific Ocean over what is now the western United States. Such a river was much sought with several candidates identified before the Buenaventura River. Explorers were seeking the Great River of the West that would be the western seg- ment of a coast-to-coast waterway, an easy route for travel and trade. Coloring these explorations was the dream of a Northwest Passage. A map by Robert Sayer (1750?) has the Great River of the West flowing from Lake Winnipeg. Albert Finley’s influential 1826 map continued the myth of the Buenaventura River as the Great River of Historian Bernard DeVoto wrote of the the West, a segment of a coast-to-coast waterway. Great River of the West: “It must exist be- cause it had to. The logic of deduction from Nanotechnology Promises Water Resource known things required it to, and so did the Gains But Raises Concerns syllogism of dream — both on no grounds whatever.” Small world of nanotechnology is big research area by Joe Gelt Settlers facing the vast expanse between the Rockies and the Sierra Nevada believed Some say a nanorevolution is at hand, perhaps not an overly zealous assessment considering fervently in this riverine mirage. John Melish the emerging pervasiveness of nanotechnology and its rapid pace of development. The water in 1816 and Albert Finley in 1826 (See Finley resource field is among those areas expected to benefit from nanotechnology, its application map at right) both drew maps displaying holding special promise for treatment and remediation; sensing and detection; and pollution the Buenaventura connecting the Great Salt prevention. That cuts a rather wide swath in the water resources field. The nanorevolution or movement is being met with both optimism and caution as scien- Continued on page 4 tists ponder how best to take advantage of its benefits and at the same time understand and reckon with its possible risks. What is Nanotechnology? A promising prospect with something of a sci-fi appeal, nanotechnology or nanotech is about size rather than a particular scientific discipline. Nanomaterial, a billionth of a meter, is Features.......................... 1 to matter what a nanosecond is to time, a billionth of a second. A nanometer is roughly 10,000 WRRC News and times smaller than the diameter of a human hair and 1 million times smaller than a single grain Information............... 3 of sand. Without hyperbole, Nano Magazine, devoted to covering nanotech issues, bills itself as Legislation and Law...... 4 the “Magazine for Small Science.” Guest View................... 5 Understanding the small science of nanotechnology requires thinking at an ultrasmall scale, downscaling one’s perceptions to the atomic and molecular level. Researchers at the nanoscale Special Projects............. 6 work to control matter about 100 nanometers or smaller, the smallest particles of matter that Student Writing Contest.... 7 can be manipulated. Public Policy Review.... 11 Nanotech involves assembling atoms and molecules to meet exact specifications to create Continued on page 2 2 Arizona Water Resource Spring 2010 Nanotechnology...continued from page 1 softening water and treating wastewater. Meanwhile new classes of new materials or modify existing ones. Nano-scaled materials and nanoporous materials are in the works with pores sufficiently small devices can be developed with a vast range of applications. Stuart to filter out the tiniest micro-organism. Lindsay, Arizona State University Regents’ professor and director Further, the pores can be developed that are straighter than con- of the Biodesign Institute’s Center for Single Molecule Biophysics, ventional filters allowing water to flow through faster. Acting as a says, “What is so striking is that events occurring at the nanoscale physical barrier, the membrane filters out particles and microorgan- have implications for chemistry, biology, physics, materials science, isms larger than its pores and selectively rejects substances. Nano- engineering, you name it.” Lindsay is the author of the just released technology may significantly reduce the cost of desalination. “Introduction to Nanoscience,” a comprehensive guide to the Work is underway to apply nanocatalysts and magnetic nanopar- nanotech world. ticles to treat heavily polluted water for use in drinking, sanitation Even prior to the recent burgeoning interest, nanotechnology and irrigation. Nanocatalysts have stronger catalytic properties due had been used in water treatment. Troy Benn, an ASU researcher in to their nanosize or their modification at the nanoscale. They can environmental engineering, explains: “Water treatment has always chemically degrade pollutants including those that current technolo- worked at the nanoscale but it was not recognized as nanotechnol- gies treat inefficiently and at great cost. ogy. Nanotech is about size, and for years filtration has worked Also, research is looking at the use of magnetic nanoparticles to at the nanoscale. Dissolved ions or particles are removed at the bind with contaminants that are then removed by a magnet. Having nanoscale.... What is new today is a greater control of the process.” large surface areas relative to their volume, magnetic nanoparticles Key to understanding the workings of nanotechnology and its readily bind with water-borne contaminants such as arsenic or oil. possible real world applications is knowing the changes that occur Along with treating water-borne contaminants nanotechnology also to materials at the nanoscale. Nanomaterials are not merely a greatly can be applied to detect them. New sensor technologies combining downsized version of the same material at the micro or macroscale; micro and nanofabrication are being developed to create small, por- the physical and chemical properties of nano-scaled materials often table and highly accurate sensors capable of detecting single cells of change from what characterizes them at the bulk scale. chemical and biochemical substances in water. For example, nanotitanium dioxide is a more effective catalyst Another promising application of nanotechnolgy is its use than microscale titanium dioxide and can be used to treat water by to address water problems in developing countries by helping to chemically degrading organic pollutants that are harmful to the en- resolve technical challenges to removing water contaminants. Nano- vironment. Nanosilver also is used to disinfect drinking water. Both technology holds promises for more varied, affordable, effective are successful adaptions to the nanoscale to serve a beneficial use. water treatment methods that are more adaptable to the needs of Other materials at the nanoscale might act differently, possibly pos- developing countries. ing environmental or health hazards. Researchers seek to optimize Nanotechnolgy research is underway at Arizona universities. See nano-benefits and avoid nano-risks. page 6 for a description of a University of Arizona research project Regulatory problems have arisen because of possible changes using nano scale zero valent iron to bioremediate water containing occurring at the nanoscale. Of an earlier vintage, current regulations uranium. James A. Field and Reyes Sierra of the UA department do not adequately address the development and use of nanoma- of chemical and environmental engineering are conducting the re- terials. Complicating the regulatory task is the need to determine search. The two researchers along with Farhang Shadman, also from if a nanomaterial is actually a new substance or not. This can be ChEE, Scott Boitano, UA college of medicine, and Buddy Ratner, a controversial issue. EPA would have the authority to regulate a University of Washington, also are involved in a project studying nanoform if its different properties warrant it being considered a the toxicity of nano-sized materials for the semi-conductor industry. new substance. In another project Sierra, Shadman and Field are looking at the fate Nanotechnology and Water of nanoparticles in municipal wastewater treatment plants. Some nano-scaled particles have properties that make them very At ASU, Paul Westerhoff, civil, environmental and sustainable suitable for treating water. They often have enhanced catalytic prop- engineering, has researched the fate of commercial nanomaterials in erties, with the potential to improve such processes as adsorption, drinking water and wastewater treatment plants, and their potential catalysis and disinfection. Nanoparticles are especially valued as a human toxicity. type of building block to custom make other particles for specific Caution is Urged applications. Amidst the promising news, the potential risks of nanotechnol- A prime water resource application of nanotechnology is to fur- ogy are not to be overlooked, with some advocating more research ther improve membrane