Evaluation of Germicidal UV-LEDs Inactivation and Photoreactivation Efficiency on Escherichia coli in Municipal Sewage

Abstract:

Ultraviolet light emitting diodes(UV-LEDs)presenting the advantages of high efficiency,small size,energy saving and without mercury,are gradually replacing mercury lamps in disinfection systems.This study focused 280nm wavelength of UV-LEDs,the Escherichia coli was served as objective in wastewater,the inactivation efficiency and photoreactivation percentage were examined compared with traditional mercury lamps.A series of UV-LEDs dose caused different inactivationefficiency and photoreactivation percentage of E.coli.When UV dose was 1.8 mJ/cm2, inactivation efficiency reached 2.7-lg,then under a 40w sunlight lamp irradiation,the photoreactivation percentage was up to 2.7%;at 3.6 mJ/cm2, inactivation efficiency reached 3-lg,photoreactivation percentage was up to 0.98%.In advanced wastewater treatment,a threshold dose 3.6 mJ/cm2 is suggested of 280nm UV-LEDS.UV dose higher than 3.6 mJ/cm2 can achieve the depth of sterilization effect,that reaches the effect of mercury lamp 40mJ/cm2.The results indicate great advantages of UV-LEDs compared with mercury lamps.

• Periodical: Advanced Materials Research (Volumes 807-809)
• Pages: 1283-1289
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.807-809.1283
• Online since: September 2013
• Authors: Lei Wang, Yu Jiao Sun, Xiao Hui Zhao, Hui Chun Zhang
• Keywords: Escherichia coli, Inactivation Efficiency, Photoreactivation, UV-LED

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