TEL AVIV, Israel, April 22 (UPI) — Most water treatment plants use chlorine to keep water free of bacteria but Israeli scientists say ultraviolet light might be a better method.
Tel Aviv University postdoctoral researcher Hadas Mamane, doctoral student Anat Lakretz, Professor Eliora Ron and their team said although chlorine keeps water free of micro-organisms, it also produces carcinogenic byproducts.
The scientists say they recently determined the optimal UV wavelength water treatment plants and large-scale desalination facilities could use to destroy health-threatening micro-organisms, as well as make the facilities more efficient.
“UV light irradiation is being increasingly applied as a primary process for water disinfection,” Lakretz said. “In our recent study, we’ve shown how this treatment can be optimized to kill free-swimming bacteria in the water — the kinds that also stick inside water distribution pipes and clog filters in desalination plants by producing bacterial biofilms.”
The researchers said they used lamps that emit a multi-wavelength UV spectrum and are more advanced than the single-wavelength UV lamps found in home water systems.
“The best way to control and kill these micro-organisms was to damage their DNA,” Lakretz said. “The damage that the UV light causes has no known negative effect on the water.”
The scientists noted their approach is even more helpful against parasites that aren’t adversely affected by chlorine treatment but place children, the elderly and those in developing nations at particular risk.
Small amounts of chlorine or other oxidants will still be necessary to make sure residual bacteria don’t enter the water further along the distribution pipeline, the researchers said.
The study appears in the journal Biofouling.
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