Efficient Disinfection of Tap and Surface Water with Single High Power 285 nm LED and Square Quartz Tube

Heßling, Martin; Gross, Andrej; Hoenes, Katharina; Rath, Monika; Stangl, Felix; Sift, Michael

doi:10.3390/photonics3010007

Cited by 6 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the one hand, legionellae have the ability to repair this kind of DNA damage in the presence of light with the help of the enzyme photolyase [ 3 ], and on the other hand, the penetration depth of UV-C radiation in water is very low. Depending on the degree of contamination, it can be determined within the millimeter or centimeter range [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

Photoinactivation of Legionella rubrilucens by visible light

Schmid

Hoenes

Rath

et al. 2017

EuJMI

View full text Add to dashboard Cite

In this study, the photoinactivation of Legionella by visible light is investigated. The success of this approach would offer new prospects for technical water disinfection and maybe even for therapeutic measures in cases of Legionella infections. Therefore, Legionella rubrilucens was dispensed on buffered charcoal yeast extract medium agar plates and illuminated with different doses of violet light generated by 405 nm light-emitting diodes (LEDs). A strong photoinactivation effect was observed. A dose of 125 J/ cm2 reduced the bacterial concentration by more than 5 orders of magnitude compared to Legionella on unirradiated agar plates. The necessary dose for a one log-level reduction was about 24 J/cm2. These results were obtained for extracellular L. rubrilucens, but other Legionella species may exhibit a similar behavior.

show abstract

Section: Introductionmentioning

confidence: 99%

Photoinactivation of Legionella rubrilucens by visible light

Schmid

Hoenes

Rath

et al. 2017

EuJMI

View full text Add to dashboard Cite

show abstract

“…Sommer et al (1996) found that the use of an aluminum reflector increased the reduction equivalent fluence (REF) of a UV disinfection device by over 40% at a water UV transmittance (UVT) of 97%. Recently, with a rapid progress in UV light emitting diodes (UV-LEDs), UV reactors employing this new light source have been developed, and reflectors made of aluminum or other highly reflective materials have been applied to make the best use of UV radiation inside the reactor chamber (Hessling et al, 2016;Wurtele et al, 2011). Nevertheless, researches concerning how the reflected UV radiation contributes to the UV reactor performance are still very limited, compared to the abundant works discussing the effect of the reactor hydrodynamics (Sozzi and Taghipour, 2006a;Wols et al, 2011;Xu et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Impact of inner-wall reflection on UV reactor performance as evaluated by using computational fluid dynamics: The role of diffuse reflection

Bolton

et al. 2017

Water Research

View full text Add to dashboard Cite

Making use of the reflected ultraviolet (UV) radiation with a reflective inner wall is a promising way to improve UV reactor performance. In this study, the impact of inner-wall reflection on UV reactor performance was evaluated in annular single-lamp UV reactors by using computational fluid dynamics, with an emphasis on the role of diffuse reflection. The UV radiation inside the reactor chamber was simulated using a calibrated discrete ordinates radiation model, which has been proven to be a reliable tool for modeling fluence rate (FR) distributions in UV reactors with a reflective inner wall. The results show that UV reactors with a highly reflective inner wall (Reflectivity = 0.80) had obviously higher FRs and reduction equivalent fluences (REFs) than those with an ordinary inner wall (Reflectivity = 0.26). The inner-wall diffuse reflection further increased the reactor REF, as a result of the elevated volume-averaged FR. The FR distribution uniformity had conditioned contributions to UV reactor performance. Specifically, in UV reactors with a plug-like flow the FR distribution uniformity contributed to the REF to some extent, while in UV reactors with a mixed flow it had little influence on the REF. This study has evaluated, for the first time, the impact of inner-wall diffuse reflection on UV reactor performance and has renewed the understanding about the contribution of FR distribution uniformity to UV reactor performance.

show abstract

“…The use of ultraviolet light has been proven to be effective for microbial inactivation by damaging bacterial DNA [ 13 , 14 , 15 ]. Pathogens absorb the ultraviolet (UV) light and thymine dimers are formed, blocking transcription and replication, which ultimately lead to cell death [ 15 , 16 ].…”

Section: Introductionmentioning

confidence: 99%

UV-C LED Irradiation Reduces Salmonella on Chicken and Food Contact Surfaces

Calle

Fernandez

Montoya

et al. 2021

Foods

View full text Add to dashboard Cite

Ultraviolet (UV-C) light-emitting diode (LED) light at a wavelength of 250–280 nm was used to disinfect skinless chicken breast (CB), stainless steel (SS) and high-density polyethylene (HD) inoculated with Salmonella enterica. Irradiances of 2 mW/cm2 (50%) or 4 mW/cm2 (100%) were used to treat samples at different exposure times. Chicken samples had the lowest Salmonella reduction with 1.02 and 1.78 Log CFU/cm2 (p ≤ 0.05) after 60 and 900 s, respectively at 50% irradiance. Higher reductions on CB were obtained with 100% illumination after 900 s (>3.0 Log CFU/cm2). Salmonella on SS was reduced by 1.97 and 3.48 Log CFU/cm2 after 60 s of treatment with 50% and 100% irradiance, respectively. HD showed a lower decrease of Salmonella, but still statistically significant (p ≤ 0.05), with 1.25 and 1.77 Log CFU/cm2 destruction for 50 and 100% irradiance after 60 s, respectively. Longer exposure times of HD to UV-C yielded up to 99.999% (5.0 Log CFU/cm2) reduction of Salmonella with both irradiance levels. While UV-C LED treatment was found effective to control Salmonella on chicken and food contact surfaces, we propose three mechanisms contributing to reduced efficacy of disinfection: bacterial aggregation, harboring in food and work surface pores and light absorption by fluids associated with CB.

show abstract

Efficient Disinfection of Tap and Surface Water with Single High Power 285 nm LED and Square Quartz Tube

Cited by 6 publications

References 16 publications

Photoinactivation of Legionella rubrilucens by visible light

Photoinactivation of Legionella rubrilucens by visible light

Impact of inner-wall reflection on UV reactor performance as evaluated by using computational fluid dynamics: The role of diffuse reflection

UV-C LED Irradiation Reduces Salmonella on Chicken and Food Contact Surfaces

Contact Info

Product

Resources

About