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

2013 ◽  
Vol 807-809 ◽  
pp. 1283-1289
Author(s):  
Lei Wang ◽  
Yu Jiao Sun ◽  
Xiao Hui Zhao ◽  
Hui Chun Zhang
Keyword(s):  
Escherichia Coli ◽  
High Efficiency ◽  
Municipal Sewage ◽  
Mercury Lamp ◽  
Light Emitting ◽  
Uv Dose ◽  
Inactivation Efficiency ◽  
Uv Leds ◽  
Ultraviolet Light Emitting Diodes ◽  
Sterilization Effect

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.

scholarly journals 310 nm UV-LEDs attenuate imiquimod-induced psoriasis-like skin lesions in C57BL/6 mice and inhibit IL-22-induced STAT3 expression in HaCaT cells

2020 ◽  
Vol 19 (8) ◽  
pp. 1009-1021
Author(s):  
Tae-Rin Kwon ◽  
Sung-Eun Lee ◽  
Jong Hwan Kim ◽  
You Na Jang ◽  
Su-Young Kim ◽  
...  
Keyword(s):  
Light Source ◽  
Ultraviolet Light ◽  
Light Emitting Diodes ◽  
Skin Lesions ◽  
Hacat Cells ◽  
Light Emitting ◽  
Uv Leds ◽  
Ultraviolet Light Emitting Diodes

Ultraviolet light-emitting diodes (UV-LEDs) are a novel light source for phototherapy.

Development of an Al2O3 filled composite for the bracket of ultraviolet light-emitting diodes (UV-LEDs)

2018 ◽  
Vol 83 ◽  
pp. 356-362 ◽  
Author(s):  
Lei Zhang ◽  
Yiting Zheng ◽  
Jiale Mao ◽  
Shuang Wang ◽  
Ruotian Fu ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Uv Leds ◽  
Ultraviolet Light Emitting Diodes ◽  
Filled Composite

ACCURATE MEASUREMENT OF ULTRAVIOLET LIGHT-EMITTING DIODES

2021 ◽  
Author(s):  
C. Yuqin Zong ◽  
Cameron Miller
Keyword(s):  
Ultraviolet Light ◽  
Light Emitting Diodes ◽  
Luminous Flux ◽  
Junction Temperature ◽  
Integrating Sphere ◽  
Light Emitting ◽  
Type D ◽  
Uv Led ◽  
Uv Leds ◽  
Ultraviolet Light Emitting Diodes

We have developed a new calibration capability for 200 nm to 400 nm ultraviolet light-emitting diodes (UV LEDs) using a Type D gonio-spectroradiometer. The recently-introduced mean differential continuous pulse (M-DCP) method is used to overcome the measurement difficulty associated with the initial forward voltage, VF, anomaly of a UV LED, which makes it impossible to use VF to infer junction temperature, TJ, during pulsed operation. The new measurement facility was validated indirectly by comparing the measured total luminous flux of a white LED with that measured using the NIST’s 2.5 m absolute integrating sphere. The expanded calibration uncertainty for the total radiant flux is approximately 2 % to 3 % (k = 2) depending the wavelength of the UV LED.

scholarly journals Effect of electrical injection-induced stress on interband transitions in high Al content AlGaN MQWs

RSC Advances ◽  
2017 ◽  
Vol 7 (87) ◽  
pp. 55157-55162 ◽  
Author(s):  
Jinjian Zheng ◽  
Jinchai Li ◽  
Zhibai Zhong ◽  
Wei Lin ◽  
Li Chen ◽  
...  
Keyword(s):  
Valence Band ◽  
Light Extraction ◽  
Interband Transitions ◽  
Light Emitting ◽  
Al Content ◽  
Induced Stress ◽  
Deep Ultraviolet ◽  
High Al Content ◽  
Uv Leds ◽  
Ultraviolet Light Emitting Diodes

The light extraction from AlGaN deep ultraviolet light-emitting diodes (UV LEDs) is known to be limited by the fundamental valence band crossover issue.

High-Efficiency 352 nm Quaternary InAlGaN-Based Ultraviolet Light-Emitting Diodes Grown on GaN Substrates

2004 ◽  
Vol 43 (No. 10A) ◽  
pp. L1241-L1243 ◽  
Author(s):  
Hideki Hirayama ◽  
Katsushi Akita ◽  
Takashi Kyono ◽  
Takao Nakamura ◽  
Koji Ishibashi
Keyword(s):  
Ultraviolet Light ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Ultraviolet Light Emitting Diodes

scholarly journals Effectiveness of visible and ultraviolet light emitting diodes for inactivation of Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli: A comparative study

2019 ◽  
Vol 15 (4) ◽  
pp. 572-576 ◽  
Author(s):  
Sameen Ahmed Malik ◽  
Tan Tian Swee ◽  
Nik Ahmad Nizam Nik Malek ◽  
Azli Yahya ◽  
Takahiro Emoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Ultraviolet Light ◽  
Exposure Time ◽  
Light Emitting Diodes ◽  
Inhibition Zone ◽  
Light Emitting ◽  
Log Reduction ◽  
Ultraviolet Light Emitting Diodes

The rapid use of ultraviolet light emitting diodes (UV-LEDs) in various disinfection applications is growing tremendously due to their advantages unachievable using UV lamps. In this study, a comparison of standard LED at 460 nm wavelength and UVA LED at 385 nm was conducted to determine their effectiveness in disinfection of frequently isolated pathogens in hospitals (Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli). Determination of disinfection efficiency was carried out by measuring inhibition zone. Effects of varied exposure time on the inactivation of pathogenic microorganisms was studied. The results demonstrated that LED does not have germicidal activities. The highest inactivation for UVA LED was achieved for Pseudomonas aeruginosa. Linear relationship was found between exposure time and log reduction. This study showed that UVA LEDs can effectively inactivate significantly higher number of microorganisms hence can be used in disinfection of various applications.

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