A University of Florida (Gainesville) engineering professor said an indoor air cleaning system originally developed to zap dust mites and mold spores also destroys airborne anthrax and other pathogenic microbes. The system has been successfully tested against a close cousin of the anthrax bacteria and could be installed relatively inexpensively and quickly in office and home heating and air conditioning systems, said Yogi Goswami, a UF professor of mechanical engineering and director of UF's Solar Energy and Energy Conversion Laboratory. "There are other technologies for air cleaning, but for air disinfection, there is no more effective system," Goswami said.
The photocatalytic air cleaning system relies on the interaction between light and titanium dioxide, a simple and widely available chemical. When light is absorbed into the titanium dioxide, it acts as a catalyst to produce an oxidizing agent. The agent, called a hydroxyl radical, "is like a bullet for the bacteria," Goswami said, destroying dust mites, mold spores and pathogens by disrupting or disintegrating their DNA.
In the detection realm, a researcher working under a U.S. Office of Naval Research grant is reportedly "just a couple of months away" from completing a prototype detector designed to sound an alarm when airborne microbes such as anthrax are in the air. Dr. Jeanne Small, a biophysicist and professor of chemistry and biochemistry at Eastern Washington University (Cheney, WA), has come up with a detector that continuously samples the air, offering analysis in under a half-hour. "Our research showed that common substances such as road dust and soot behaved differently than bacteria," Small said.
Small successfully tested biological particles ranging in size from 1 to 10 microns by using lasers and acoustic sensors to detect and identify microbes. In the research, laser pulses were used to excite light-absorbing substances that release energy as heat. Heat-induced solvent expansion generated sound waves, which were measured by an ultrasonic transducer.
Publication date: 11/05/2001