Pulsed UV lamp performance and comparison with UV mercury lamps

Schaefer, R.; Grapperhaus, Michael; Schaefer, Ian; Linden, Karl G.

doi:10.1139/s06-068

Cited by 44 publications

(18 citation statements)

References 12 publications

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“…For Ad40 testing, the quantitative spectra of all lamps, including conventional LP and MP mercury lamps and a pulsed surface discharge (SD) lamp (11,12,13), were measured using a multichannel spectrometer, convenient for capturing the entire UV spectra of polychromatic lamps. The measurements used an Ocean Optics (model USB2000) multichannel spectrometer with 2,048 elements over the wavelength range of 200 to 800 nm.…”

Section: Methodsmentioning

confidence: 99%

“…Ad40 was exposed to UV irradiation from LP, MP, and PUV irradiation under similar CB conditions. The LP and MP sources were conventional continuous-wave UV sources, while the PUV system utilized an SD lamp developed by Phoenix Science and Technology (Chelmsford, MA) (11,12,13). The UV inactivation data are presented in Fig.…”

Section: Fig 2 Description Of the Geometry For The Test Cell Used Tmentioning

confidence: 99%

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Enhanced UV Inactivation of Adenoviruses under Polychromatic UV Lamps

Linden

Thurston

Schaefer

et al. 2007

Appl Environ Microbiol

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Adenovirus is recognized as the most UV-resistant waterborne pathogen of concern to public health microbiologists. The U.S. EPA has stipulated that a UV fluence (dose) of 186 mJ cm ؊2 is required for 4-log inactivation credit in water treatment. However, all adenovirus inactivation data to date published in the peer-reviewed literature have been based on UV disinfection experiments using UV irradiation at 253.7 nm produced from a conventional low-pressure UV source. The work reported here presents inactivation data for adenovirus based on polychromatic UV sources and details the significant enhancement in inactivation achieved using these polychromatic sources. When full-spectrum, medium-pressure UV lamps were used, 4-log inactivation of adenovirus type 40 is achieved at a UV fluence of less than 60 mJ cm ؊2 and a surface discharge pulsed UV source required a UV fluence of less than 40 mJ cm ؊2 . The action spectrum for adenovirus type 2 was also developed and partially explains the improved inactivation based on enhancements at wavelengths below 230 nm. Implications for water treatment, public health, and the future of UV regulations for virus disinfection are discussed.UV disinfection is a well-accepted technology for inactivation of bacterial and protozoan pathogens. Until recently, UV was also considered a viable technology for disinfection of viruses. At UV fluences (doses) typically used in water disinfection, UV is very effective (Ͼ4-log inactivation) against almost all known pathogenic viruses, with the one exception of adenoviruses (5). Adenovirus has been recently listed on the U.S. EPA Candidate Contaminant List, which indicates that it is a high priority for possible future regulation and is known or anticipated to occur in public water systems, but significant data gaps need to be addressed before regulation can be invoked. According to recently published U.S. EPA regulations (17), the inactivation of adenoviruses to a level of 4 log requires a UV fluence of 186 mJ cm Ϫ2 , based on an 80% credible interval, as presented in the Draft UV Disinfection Guidance Manual (16). The U.S. EPA-regulated UV fluence for inactivation of all viruses is now based on the conservative case of adenoviruses. Yates et al. (18) provide an excellent review of the issues surrounding the UV inactivation of adenovirus.Although data sets for UV inactivation of adenovirus differ moderately, they all place adenovirus as the most UV-resistant health-related virus known. However, all peer-reviewed published studies to date have been performed using a low-pressure (LP) mercury vapor UV lamp source characterized by a monochromatic output in the UV range at 253.7 nm. Based on these LP UV irradiation studies, the UV fluence necessary to achieve 4-log inactivation of adenovirus varies from 120 to approximately 180 mJ cm Ϫ2 . For adenovirus type 5 (Ad5), the required UV fluence is 160 to 170 mJ cm Ϫ2 (1), which is similar to those required for Ad1 (9), Ad2 (1, 5), Ad6 (9), and Ad40 and Ad41 (8). However, there are two studies that repo...

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Section: Methodsmentioning

confidence: 99%

Section: Fig 2 Description Of the Geometry For The Test Cell Used Tmentioning

confidence: 99%

Enhanced UV Inactivation of Adenoviruses under Polychromatic UV Lamps

Linden

Thurston

Schaefer

et al. 2007

Appl Environ Microbiol

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“…The PUV lamps have been employed especially in inactivation of bacteria and viruses (Schaefer et al 2007;Bohrerova et al 2008;Daryany et al 2009). PUV produces polychromatic high-intensity light via high-power electrical pulses in microsecond bursts.…”

Section: Pulsed Uv Lampsmentioning

confidence: 99%

“…In addition, the efficiency (energy converted to light) is greater. However, the lifetime of flashlamp type PUV lamp has been less than that of MP lamp, yet the SD type lamp is expected to have longer lifetime (Schaefer et al 2007). In comparison with LP and MP lamps for Escherichia coli (E. coli) inactivation, PUV lamps demonstrated much higher treatment efficiency (Bohrerova et al 2008).…”

Section: Pulsed Uv Lampsmentioning

confidence: 99%

Recent developments in photochemical and chemical AOPs in water treatment: a mini-review

Vilhunen

Sillanpää

2010

Rev Environ Sci Biotechnol

120

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Photochemical and chemical oxidation methods, belonging to a wide group of advanced oxidation processes (AOPs), are extensively studied but still under constant development. The aim of this study was to review the recent developments mainly in UV/H 2 O 2 process and Fenton's reactions. Ultraviolet (UV) radiation is an essential factor in photochemical oxidation. In the development of UV radiation sources the energy efficiency and the use of toxicant free materials have become major objectives. Also the emitted wavelength plays a significant role. Besides, there are alternatives for UV radiation sources, such as radio frequency (RF) plasmas, which can operate in water without additional chemicals. A remarkable development in the field of chemical oxidation has been novel catalyst materials for Fenton's reaction enabling the efficient reaction in neutral or almost neutral conditions, instead of pH below 3. In addition, varieties of method integrations, e.g., combinations of AOPs or AOPs integrated to biological processes, and other enhancements such as combining ultrasound (US) with AOP have led to improved water treatment efficiencies.

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“…They are often used in spectrofluorimeters. Xenon arc discharges show a bright continuum in UV-VIS part of the spectrum [9] that allows to vary the excitation wavelength by use of interference filters and to be flexible for different applications. Compared to lasers, the radiation power of xenon flash lamps is lower and decay time is significantly longer.…”

Section: Introductionmentioning

confidence: 99%

Optimization of a Dielectric Barrier Discharge for Pulsed UV Emission of XeCl at 308 nm

Pipa

Bussiahn

2011

Contrib. Plasma Phys.

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A pulsed dielectric barrier discharge (DBD) has been investigated in a wide range of experimental conditions with the purpose of optimization for XeCl excimer radiation. For that the following operation parameters had been considered: four different lamps of coaxial geometry with gas gaps in the range of 1.3 -6.5 mm; gas mixtures of xenon and chlorine containing admixtures of 1%, 2% and 4% Cl2 at total filling pressures between 5 mbar and 600 mbar; voltage rise times of 20 -50 ns and voltage amplitudes of up to 12 kV. A maximum radiation pulse energy of 1.8 μJ has been detected at 310 ± 10 nm with an estimated radiation decay by three orders of magnitude within about 5 μs. It was shown that the minimization of the voltage rise time is essential for enhancing the radiation pulse energy. Furthermore a correlation between the discharge geometry and the optimum pressure for maximum radiation output was observed. The decay characteristics of the excimer emission provides evidence of the harpoon reaction being the main channel of XeCl formation under our operation conditions.

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Pulsed UV lamp performance and comparison with UV mercury lamps

Cited by 44 publications

References 12 publications

Enhanced UV Inactivation of Adenoviruses under Polychromatic UV Lamps

Enhanced UV Inactivation of Adenoviruses under Polychromatic UV Lamps

Recent developments in photochemical and chemical AOPs in water treatment: a mini-review

Optimization of a Dielectric Barrier Discharge for Pulsed UV Emission of XeCl at 308 nm

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