FEB. 24–ATLANTA, Ga.–Georgia Institute of Technology researchers have developed a better-performing, less costly method of disinfecting water used in food processing.

Like current technologies, the new Advanced Disinfection Technology System relies on ultraviolet (UV) radiation to eliminate molds, viruses and bacteria. But the new system handles water more efficiently and thus improves the overall effectiveness of the disinfection process, researchers reported.

“We’re creating a mixing pattern to ensure that every particle of water is equally exposed to the (UV) lamp,” said John Pierson, a senior research engineer at the Georgia Tech Research Institute and co-principal investigator. “By doing a better job of mixing the water, you get better disinfection.”

Federal regulations require the disinfection of water used in food processing before it can be reused. In many cases, the lack of cost-effective disinfection means water is used only once and then discarded. When a disinfection system is used, the process is not always effective.

Most existing systems pump water through pipes lined with dozens of UV lamps. The lamps tend to foul quickly, reducing their effectiveness and requiring ongoing cleaning and replacement. More important, UV light has little penetrating power — just about an inch — so used water must be run through long pipes to increase the likelihood that UV light will contact enough of the liquid to affect the microorganisms it carries.

“Water right up against the lamp gets treated, and water farther away gets treated less — or maybe not treated at all,” explained Pierson, who is collaborating on the advanced disinfection system with Larry Forney, project director and an associate professor of chemical engineering at Georgia Tech.

The heart of the new advanced system is a pair of cylinders, one inside the other. The smaller cylinder rotates inside the stationary outer cylinder while water is pumped through the gap separating the two.