medium pressure ultraviolet lamp Articles
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Aging evaluation of medium-pressure mercury lamps under typical operating conditions for drinking water disinfection applications
Little is known regarding how medium pressure (MP) ultraviolet (UV) lamps age under typical operating conditions, yet a number of assumptions regarding lamp aging are utilized when UV reactors are validated, often as unfounded approximations. This study was designed to evaluate the aging of MP UV lamps utilized with a closed-vessel UV reactor technology for drinking water disinfection ...
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Effect of photoreactivation on ultraviolet inactivation of
Microcystis aeruginosa Microcystis aeruginosa forms algal bloom in lakes. They produce toxic compounds such as microcystin. Against such algal problems, the effect of UV treatment was examined. In UV treatment, the effect of photoreactivation should be examined. Photoreactivation is a repair mechanism of genomic DNA damage by sunlight irradiation. UV treatment causes DNA damages on target cyanobacteria, however ...
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Determination of pyrimidine dimers in the genomic DNA of Escherichia coli during photoreactivation following inactivation by medium-pressure UV lamp
A polychromatic medium-pressure (MP) UV lamp was compared with a monochromatic low-pressure (LP) UV lamp to investigate the inactivation and the subsequent photoreactivation of Escherichia coli . An endonuclease sensitive site (ESS) assay was applied to determine the number of UV-induced pyrimidine dimers in the genomic DNA of E.coli in parallel with a conventional colony forming assay. more than ...
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Spectral distribution of uv light during aging of medium pressure UV lamps
As part of a project to validate a UV reactor for disinfection of drinking water, the germicidal output of four medium pressure lamps housed in a continuously operating reactor was followed as a function of time. Spectra were measured monthly and were used in conjunction with radiometer readings to calculate germicidal fluence rates (using DNA absorbance weighting) at the radiometer sensor ...
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Potential Repair of Escherichia coli DNA following Exposure to UV Radiation from Both Medium- and Low-Pressure UV Sources Used in Drinking Water Treatment
The increased use of UV radiation as a drinking water treatment technology has instigated studies of the repair potential of microorganisms following treatment. This study challenged the repair potential of an optimally grown nonpathogenic laboratory strain of Escherichia coli after UV radiation from low- and mediumpressure lamps. Samples were irradiated with doses of 5, 8, and 10 mJ/cm2 from a ...
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Reduction of
Escherichia coli bacteria from contaminated water by combining hydrogen peroxide, ozone and ultraviolet lightThis study demonstrates the reduction of Escherichia coli bacteria from contaminated water when the water is treated with advanced oxidation processes utilising the following combinations: hydrogen peroxide (H2O2) and ozone (O3), ultraviolet light (UV) and hydrogen peroxide (H2O2), and ultraviolet light (UV) and ozone (O3). Approximately 1 × 108cell/mL of E. coli were spiked into water ...
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Comparison of Low and Medium Pressure UV
DESTRUCTION OF PATHOGENS (Bacteria, Viruses, Protozoan Cysts): Both Conventional (low pressure) and Medium pressure UV will assist chlorine in disinfection including the destruction of all bacteria, viruses and protozoan cysts on a single pass. DESTRUCTION OF CHLORAMINES: Monochloramine (NH2Cl), Dichloramine (NHCl2), and Nitrogen Trichloride (NCl3) are the products of nitrogen introduction ...
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Effects of natural organic matter and nitrate on the behavior of nitrosodimethylamine during ultraviolet irradiation and chloramination
Nitrosodimethylamine (NDMA), a potent carcinogen, is found in natural and engineered water systems. Ultraviolet (UV) treatment is potentially a useful tool for controlling NDMA at water purification plants. However, a recent study has reported that UV/advanced oxidation process (AOP) treatment may provide a source of NDMA precursors. Therefore, we investigated the effect of UV treatment on the ...
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How UV can reduce corrosion in swimming pool structure - Case Study
UV reduces the risk of stress corrosion cracking by removing the root cause – chloramines. The polychromatic emission of medium pressure UV lamps breaks the chlorine-nitrogen bond in chloramine molecules by photolysis. In 1985, twelve people were killed in Uster, Switzerland when the concrete roof of a swimming pool collapsed after only thirteen years of use. The roof was supported by ...
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SOFI - Case Study
Liquid Sugar Disinfection atg UV Technology, market leaders in the Ultraviolet treatment industry have supplied SOFI, atg UV’s French distributors with three state-of-the-art, ultra compact SS-73-4 Ultraviolet disinfection systems for the treatment of sugar syrup solutions. The systems where supplied to a market leading Algerian food and beverage manufacture who required effective ...
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Water treatment for swimming pools – Spas & hydro pools - Case Study
UV manufacturers now offer a specialist range of UV systems providing tailored water treatment for swimming pools to meet the requirements of spas and hydro pools. Increased Adoption of UV Water Treatment For Swimming Pools With the rise of health centres and leisure clubs throughout the UK, a key feature in many modern facilities is the inclusion of spas and hydro pools. As a ...
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Scale-up of a Medium Pressure UV System for the Treatment of N-Nitrosodimethylamine (NDMA) and its Advantages Over Low Pressure UV Systems
Recently there has been considerable concern in California about the detection of N-nitrosodimethylamine (NDMA) in drinking water at levels as high as 900 ppt. NDMA was found to be a carcinogen in animals and assessed as a Class 1 carcinogen. It is currently listed as a priority pollutant on the US EPA National Priorities List. California has set an 'action level' of 20 ppt for NDMA. NDMA is ...
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UV systems for spas & hydro pools - Case Study
With the rise of health centres and leisure clubs throughout the UK, a key feature in many modern facilities is the inclusion of spas and hydro pools. As a specialist aquatic application, spas and hydro pools feature high turnover rates, high bather loads, increased turbulence and water temperatures above 35oC. This combination of factors provides a perfect breeding ground for harmful ...
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