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Improving Water Quality with Nanoscale Technologies
Improving Water Quality with Nanoscale Technologies

 

In 1974, Congress passed the Safe Drinking Water Act authorizing the U.S. Environmental Protection Agency (E.P.A.) to establish standards for drinking water to safeguard public health against naturally-occurring and man-made contaminants in rivers, lakes, reservoirs, springs, and groundwater supplies. As a part of a broad portfolio of water-related research, PSU faculty and students are using the latest nanotechnology to help implement regulations like these.

Trichloroethylene (TCE) is one of the compounds the E.P.A. regulates. Commonly used as an industrial solvent and in consumer products such as liquid paper, adhesives, paint thinners and spot removers, TCE poses major health risks that include: liver and kidney damage, arrhythmias, cancer and adverse reproductive and developmental effects.

The common method for removing TCE from water is to use granular activated carbon (GAC) filtration, similar to the approach used to clean hobbyists' fish tanks. However, for large-scale purification operations such as those at industrial manufacturing plants or commercial laboratories, GAC filtration of TCE is too slow and releases too many toxic byproducts that must be removed and safely stored; both factors increase overall costs at public and private water treatment facilities.

To solve this problem researchers in the lab of Dr. Jun Jiao, joint Professor of Mechanical & Materials Engineering and Physics, sought a catalytic additive that could be incorporated into existing purification systems in common use, rather than requiring the creation of an entirely new industrial system. Dr. Jiao and her colleagues developed a simple process to hybridize gold-palladium (AuPd) nanocrystals with a number carbon substrates including activated carbon. When H2 is added to TCE-tainted water passing through carbon filters enhanced with AuPd, the nanocrystals become catalysts that remove the TCE from water. With this low cost method of manufacturing carbon-supported AuPd catalysts, it is possible to greatly improve the ability of large-scale filtration systems already in place in industrial, commercial and municipal water treatment facilities to remove TCE from waste water supplies.

Initial lab results show that Dr. Jiao's method increases the rate of degradation of TCE and similar compounds by several times compared to the traditional use of activated carbon. In large-scale operations, this increased efficiency could lower the cost of materials, maintenance, and hazardous waste disposal. In the long run, public health is the real beneficiary of this innovative technology. Eliminating TCE and its toxic byproducts altogether guarantees it will not enter the environment where it poses serious health risks.

RSP’s Innovation & Intellectual Property team is working with Dr. Jiao to find partners interested in further developing this patent-pending technology. Initial studies have shown the carbon-supported AuPd catalyst to be effective not only for TCE, but also for the explosive, TNT, and the active ingredient in tear gas, 2-CAP. Dr. Jiao and her colleagues are showing that innovations at the nanoscale can have potentially huge impacts.

 

Author by Shaun McGillis
Posted August 8, 2014