Disinfection of water.

Researchers are casting new light on the disinfection of water used in food processing. They have developed a nonthermal method that performs better and is less costly than existing techniques. Like current technologies, the new system relies on ultraviolet (UV) radiation to eliminate molds, viruses and bacteria. But the new system handles water more efficiently and improves the overall effectiveness of the disinfection process. 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. Inside the gap, the cylinder rotation causes water to churn and tumble in a well-documented phenomenon called a Taylor vortex. It's actually a number of vortices that mix water with light shining from four UV lamps embedded in the outside cylinder wall. UV light penetrates the water thoroughly, so no additional cycles through the system are necessary. Preliminary work shows a reduction in the concentration of viable pathogens by a factor of more than 200, compared to existing technology with the same UV dosage. Contact: Larry Forney, School of Chemical Engineering, Georgia Institute of Technology, 311 Ferst Dr. NW, Atlanta, GA 30332. Phone: [phone]. Fax: [phone]. Email: [e-mail].