The future availability of groundwater as a source of potable water is jeopardized by the widespread occurrence of organic contaminants in water supplies. Of particular concern are volatile organic compounds (VOCs) such as trichloroethylene (TCE), and other contaminants such as polychlorinated biphenyls (PCBs). These materials are carcinogenic. Current treatment methods usually shift the contaminant to another medium, rather than converting the contaminants to environmentally benign compounds.

Researchers at Arizona State University have developed a ultraviolet-driven heterogeneous photocatalysis technique capable of converting many groundwater pollutants into non-harmful compounds. A titanium dioxide catalyst is provided in combination with ultraviolet illumination in a transparent fluidized bed photoreactor. Contaminated water is passed through the reactor, and the harmful materials are oxidized at the catalyst and converted to benign compounds. This technique can be used to eliminate or mitigate a broad class of pollutants, including VOCs, PCBs, chloroform, dichloromethane, phosphates, paraffins, olefins, and alcohols. The system can be readily integrated into existing water treatment facilities. A low-cost, low-power, highly effective water treatment system is now available.

Potential Applications

• Industrial Processes
• Water Treatment Plants
• Groundwater Treatment and Cleanup

Benefits and Advantages

• Ambient Temperature Operation – The reaction takes place at ambient temperature, eliminating the need for costly heating or cooling equipment.
• Highly Effective – The process is more than 99% effective at oxidizing many harmful compounds.
• Highly Efficient – The process uses near-wavelength ultraviolet light (around 450nm), minimizing lighting costs.

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