Application of UV Light–Emitting Diodes to Adenovirus in Water

UV-LEDs Efficiently Inactivate DNA and RNA Coliphages

“…In earlier UV-LED studies more than 3 Log 10 -reductions of coliphages φX174 and T7 were achieved with doses of 6.4-20 mWs/cm 2 at wavelengths of 255-285 nm [18,24]. Coliphages Qβ and MS2 were more resistant and they required above 40 mWs/cm 2 to reach 1-3 Log 10 -reductions [13,16,18,21,23,24]. Bowker et al [18] compared the wavelengths of 255 and 275 nm with coliphages T7 and MS2 and found rather similar inactivation rates at both wavelengths.…”

“…MS2 has also proved to be UV-resistant in other studies. Doses from 41 to 60 mWs/cm 2 were needed to reach 2-3 Log 10 -reductions of MS2 at wavelengths of 255-280 nm (excluding 270 nm) [13,18,24], while approximately 110 mWs/cm 2 was needed at 285 nm to reach 3 Log 10 -reduction [21]. However, a tunable laser at 270 nm has yielded 1.5 and at least 3 Log 10 -reductions of MS2 with doses of 20-30 mWs/cm 2 and 60 mWs/cm 2 , respectively [33,34].…”

“…Resistance of MS2 makes it a good surrogate for human enteric viruses when the efficiency, wavelength, and energy in UV disinfection are studied. Human pathogenic adenovirus 5, which is a DNA virus, seems to be slightly more resistant to UV-LED at 285 nm than MS2 [21].…”

“…Earlier studies have used sterilized water in a vertical laboratory system [14,16,24], saline-calcium or phosphate buffer saline in a collimated beam system [18,23], or 50 mL of phosphate buffer saline in a ring-shaped reactor [21]. We used 5.2 L of real municipal drinking water in the reactor where UV-LEDs were placed centrally facing in four directions.…”

“…MS2 and other UV-resistant coliphages tested by [13,16,18,21,24] were RNA viruses. In our study, however, either RNA or DNA coliphages could be UV-resistant or UV-sensitive.…”