Studies on Liposome-encapsulated-chemical Actinometer in UV-disinfection by Low Pressure UV Lamp: Bio-chemical Actinometer in UV-Disinfection

2012 ◽  
Author(s):  
Jinglan Hong ◽  
Masahiro Otaki
Keyword(s):  
Low Pressure ◽  
Uv Disinfection ◽  
Uv Lamp

scholarly journals Molecular Indications of Protein Damage in Adenoviruses after UV Disinfection

2010 ◽  
Vol 77 (3) ◽  
pp. 1145-1147 ◽  
Author(s):  
Anne C. Eischeid ◽  
Karl G. Linden
Keyword(s):  
Cell Culture ◽  
Viral Proteins ◽  
Low Pressure ◽  
Protein Damage ◽  
Uv Disinfection ◽  
Medium Pressure ◽  
The Difference ◽  
Uv Lamp ◽  
Detailed Work

ABSTRACTAdenoviruses are resistant to monochromatic, low-pressure (LP) UV disinfection—but have been shown to be susceptible to inactivation by polychromatic, medium-pressure (MP) UV—when assayed using cell culture infectivity. One possible explanation for the difference between UV lamp types is that the additional UV wavelengths emitted by MP UV enable it to cause greater damage to viral proteins than LP UV. The objective of this study was to examine protein damage in adenoviruses treated with LP and MP UV. Results show that MP UV is more effective at damaging viral proteins at high UV doses, though LP UV caused some damage as well. To our knowledge, this study is the first to investigate protein damage in UV-treated adenovirus, and the overview presented here is expected to provide a basis for further, more detailed work.

Characterization of a commercially-available, low-pressure UV lamp as a disinfection system for decontamination of common nosocomial pathogens on N95 filtering facepiece respirator (FFR) material

2020 ◽  
Vol 6 (8) ◽  
pp. 2089-2102 ◽  
Author(s):  
C. Carolina Ontiveros ◽  
Crystal L. Sweeney ◽  
Chris Smith ◽  
Sean MacIsaac ◽  
Sebastian Munoz ◽  
...  
Keyword(s):  
Low Pressure ◽  
Uv Disinfection ◽  
Nosocomial Pathogens ◽  
Hospital Room ◽  
Uv Lamp

A commercially-available UV disinfection system used for hospital room disinfection was characterized and used for N95 filtering facepiece respirator (FFR) material disinfection.

scholarly journals E. coli Inactivation Kinetics Modeling in a Taylor-Couette UV Disinfection Reactor

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
M. L. Palacios-Contreras ◽  
F. Z. Sierra-Espinosa ◽  
K. Juárez ◽  
S. Silva-Martínez ◽  
A. Alvarez-Gallegos ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Polynomial Equation ◽  
Microbial Inactivation ◽  
Uv Disinfection ◽  
Order Kinetic ◽  
E Coli ◽  
Toroidal Vortices ◽  
Angular Velocities ◽  
Uv Lamp ◽  
Kinetics Of

A simple model was developed to predict the survival behavior of E. coli subjected to UV disinfection in a Taylor-Couette reactor. The model includes the CFD evaluation of the counterrotating toroidal vortices developed within the annular space of two coaxial cylinders. The UV lamp was located within the diameter of the internal rotating cylinder. The residence time of the bacteria near the UV lamp is, therefore, a function of both the size of the vortex and its angular velocity. The effect of angular velocity on the formation of counterrotating toroidal vortices and their impact on the kinetics of UV microbial inactivation was experimentally evaluated. The kinetics of microbial inactivation follow an apparent first-order kinetic equation between 300 and 2000 revolutions per minute. Therefore, in this range of angular velocities, a set of k values (indirectly taking into account the hydrodynamic pattern and UV irradiance) was obtained for a given concentration of bacteria. Then, the set of k values was correlated with the range of angular velocities applied using the polynomial equation. A k value can be obtained for an unknown angular velocity through the polynomial equation. Therefore, a simulation curve of microbial inactivation can be obtained from the first-order kinetic equation. The efficiency of bacteria removal improves depending on the angular velocity applied. A good agreement is observed between the simulation of the survival behavior of the microorganisms subjected to UV disinfection with the experimental data.

Fifteen years of experience with standardized reference radiometers for controlling low-pressure UV disinfection plants for drinking water

2016 ◽  
Vol 17 (4) ◽  
pp. 975-984
Author(s):  
A. W. Schmalwieser
Keyword(s):  
Drinking Water ◽  
Environmental Conditions ◽  
Quality Criteria ◽  
Low Pressure ◽  
Test Methods ◽  
Radiation Monitoring ◽  
Uv Disinfection ◽  
Test Results ◽  
High Quality ◽  
The Past

The only practicable way to control the disinfection capability of a UV disinfection plant for drinking water all the time is to use a UV radiometer. According to the Austrian Standard M5873, this plant radiometer is a standardized part of each plant. The standard defines a so-called reference radiometer (RRM) as well. This is necessary because a plant radiometer has to be controlled periodically. A RRM is a hand-held device which has to fulfil high-quality criteria and must be almost insensitive to environmental conditions. In this paper the principles of the concept behind the RRM are explained together with the requirements of such a device. Further on, the test methods are presented as well as a summary of test results from all RRMs developed during the past 15 years. It is shown that the radiation monitoring concept of the Austrian Standard has been successfully practicable and that the international acceptance of the Austrian Standard is justified.

Method to determine the power efficiency of UV disinfection plants and its application to low pressure plants for drinking water

2016 ◽  
Vol 17 (4) ◽  
pp. 947-957 ◽  
Author(s):  
Alois W. Schmalwieser ◽  
Georg Hirschmann ◽  
Alexander Cabaj ◽  
Regina Sommer
Keyword(s):  
Drinking Water ◽  
Electric Power ◽  
Power Efficiency ◽  
Electrical Power ◽  
Low Pressure ◽  
Uv Disinfection ◽  
Plant Type ◽  
Uv Irradiance ◽  
Flow Through ◽  
Selection Of

In this paper we present a method to determine the power efficiency of ultraviolet (UV) disinfection plants and apply this to low pressure plants for drinking water. In UV disinfection plants the water flow is regulated to ensure that microorganisms receive the necessary fluence for inactivation while passing through. The flow depends on the UV transmission (UVT) of the water. The lower the UVT of the water is, the less water may flow through the plant. UV irradiance is produced by lamps that consume, together with other components, electrical power and entail running costs. The power efficiency – electrical power versus disinfected volume – of a plant has therefore an important impact. Applying this method to different UV plants that are on the market shows that electric power of at least 5.3 Wh is necessary to disinfect 1 m3 of water possessing a UVT of 80% (100 mm), 8 Wh at 50% and 22 Wh at 10%. Further we found that ineffective design or a wrong selection of a plant may enhance these values by a factor of up to 7. This method enables not only the calculation of the power efficiency but also the decision for a certain plant type.

Development of UV Distribution Model for the Non-Contact Type UV Disinfection System

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Sung Hong Kim ◽  
Young Gyun Choi ◽  
Dooil Kim
Keyword(s):  
Mathematical Model ◽  
Exposure Time ◽  
Uv Light ◽  
Treatment Plant ◽  
Water Layer ◽  
Distribution Model ◽  
Uv Disinfection ◽  
Contact Type ◽  
Irradiation System ◽  
Uv Lamp

Fouling on the quartz sleeve reduces the transmittance of UV light through the sleeve into the water in submerged UV disinfection system. The concept of a non-contact type of UV disinfection system was introduced in this study. UV lamps and their quartz sleeves hang over the water surface and there is no interface between the sleeve and water. Indeed, there is no fouling. Based on optical laws and UV distribution model, a detailed mathematical model for a non-contact type UV disinfection system was developed and simulated in this study. UV light passes through 4 media of air-quartz-air and water in case of non-contact type irradiation system. By the simulation of the mathematical model of the system, it is known that the non-contact type of UV system requires 2.5 times more powerful UV lamp or a lamp with longer exposure time than that of the submerged type of UV system. In a non-contact type of UV system, high-reflective ceiling material can increase the UV intensity of the water layer as much as 28 percent more than the case of non-reflective ceiling material. The non-contact type UV irradiation system requires more powerful lamp or one that have longer exposure time. Nevertheless, considering the fouling attenuation and maintenance problem associated with the fouling, non-contact type of UV disinfection system deserves to be practically considered, especially in a small to middle scale water or wastewater treatment plant.

scholarly journals Effects of UV Radiation on Photolyase and Implications with Regards to Photoreactivation following Low- and Medium-Pressure UV Disinfection

2007 ◽  
Vol 74 (1) ◽  
pp. 327-328 ◽  
Author(s):  
Jiangyong Hu ◽  
Puay Hoon Quek
Keyword(s):  
Uv Radiation ◽  
Uv Irradiation ◽  
Flavin Adenine Dinucleotide ◽  
Low Pressure ◽  
Uv Disinfection ◽  
Medium Pressure ◽  
Uv Lamps

ABSTRACT Photolyase activity following exposure to low-pressure (LP) and medium-pressure (MP) UV lamps was evaluated. MP UV irradiation resulted in a greater reduction in photolyase activity than LP UV radiation. The results suggest that oxidation of the flavin adenine dinucleotide in photolyase may have caused the decrease in activity.

Re-use of wastewater: preventing the recovery of pathogens by using medium-pressure UV lamp technology

2004 ◽  
Vol 50 (6) ◽  
pp. 337-344 ◽  
Author(s):  
B.F. Kalisvaart
Keyword(s):  
Wastewater Treatment Plants ◽  
Uv Light ◽  
Low Pressure ◽  
Energy Output ◽  
Uv Spectrum ◽  
Medium Pressure ◽  
Uv Lamp ◽  
Cellular Dna ◽  
Uv Technology ◽  
Term Performance

Ultraviolet (UV) light has become widely accepted as an alternative to chlorination or ozonation for wastewater disinfection. There are now over 2,000 wastewater treatment plants worldwide using either low- or medium-pressure UV technology. Recent studies investigating UV lamp technology, configuration, cleaning requirements and ageing, as well as long-term performance tests, have demonstrated beyond any doubt the effectiveness of UV in inactivating pathogens in wastewater. Research has also shown that, to ensure permanent inactivation and prevent the recovery of microorganisms following exposure to UV, a broad, “polychromatic” spectrum of UV wavelengths is necessary. These wavelengths inflict irreparable damage not only on cellular DNA, but on other molecules, such as enzymes, as well. Only medium-pressure UV lamps produce the necessary broad range of wavelengths; low-pressure lamps emit a single wavelength peak which only affects DNA. Polychromatic medium-pressure UV light is so effective because of the lampÕs exceptionally high UV energy output at specific wavelengths across the UV spectrum. It has been shown, for example, that pathogenic E. coli O175:H7 was able to repair the damage caused by low-pressure UV, but no repair was detected following exposure to UV from medium-pressure lamps.

Influence of lamp intensity and water transmittance on the UV disinfection of water

1997 ◽  
Vol 35 (11-12) ◽  
pp. 113-118 ◽  
Author(s):  
R. Sommer ◽  
A. Cabaj ◽  
W. Pribil ◽  
T. Haider
Keyword(s):  
Supply Voltage ◽  
Uv Disinfection ◽  
Uv Detector ◽  
Uv Irradiance ◽  
Flow Through ◽  
Uv Lamp ◽  
Uv Transmittance ◽  
Two Parameters ◽  
Uv Lamps ◽  
Irradiation Chamber

The efficiency of UV disinfection devices depends on flow, lamp intensity and water transmittance. In practice the flow is controlled by suitable methods, whereas the other two parameters, to date, have not been taken into consideration sufficiently. The surveillance of the function of UV disinfection plants is routinely based on a sensor placed on the irradiation chamber wall. This measures changes of UV irradiance without differentiating if the effect is caused by transmittance or lamp intensity so that two different conditions of disinfection may occur at the same sensor readings. We investigated the influence of transmittance vs intensity on disinfection at the same sensor readings in a specially designed laboratory flow through UV irradiation system with one single UV lamp as well as in commercially available UV disinfection plants with multiple UV lamps. All devices were equipped with a calibrated selective UV detector connected to a UV radiometer. Lamp intensity was decreased by diminishing the supply voltage. UV transmittance was reduced by pumping aqueous sodium thiosulphate solution into the water inflow. The disinfection capacity was determined by measuring the reduction equivalent doses (RED) using a standardised biodosimetric method. We showed that equal sensor readings, either achieved by reducing the lamp intensity or by lowering the UV transmittance of the water, resulted in different REDs in one-lamp systems. The diminishing of UV intensity caused a greater decrease of REDs than reducing the water transmittance. However, in the multiple-lamp systems tested, equal sensor readings yielded equal REDs.

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