scholarly journals INFLUENCE OF UV RADIATION ON THE TRANSFORMATION OF MONOAND DICHLORAMINES IN WATER OF SWIMMING POOLS IN FULL-SCALE TESTS AND IN THE EXPERIMENT

2020 ◽  
Vol 99 (3) ◽  
pp. 230-234
Author(s):  
Zoya I. Zholdakova ◽  
Yana I. Lebed-Sharlevich ◽  
Nadezda I. Belyaeva ◽  
Roman A. Mamonov
Keyword(s):  
Uv Radiation ◽  
Active Chlorine ◽  
Swimming Pools ◽  
Subsequent Reaction ◽  
Uv Treatment ◽  
Pool Water ◽  
Before And After ◽  
Aquarium Water ◽  
Uv Dose ◽  
Full Scale Tests

Introduction. The use of chlorine-containing reagents for disinfection of water in swimming pools may lead to the formation of chloramines, both worsening the organoleptic properties of water and affecting the health of swimmers. To reduce the content of chloramines in pool water, UV radiation can be used. The aim of work is investigation of the effect of UV radiation on the transformation of mono- and dichloramines in water. Material and methods. The study was conducted on water samples from children’s pools, as well as in a model experiment on aquarium water with sodium hypochlorite added. Samples were irradiated with ultraviolet at doses of 40, 80 and 120 mJ/cm2. Before and after UV treatment, the content of chloramines was determined in all samples. Results. UV dose 40 mJ/cm2 was found to be insufficient for the destruction of mono- and dichloramine in water. During UV treatment with a dose 80 mJ/cm2 a decrease in the content of monochloramines and an increase in the content of dichloramines were observed. These processes were depended on the initial concentration of active chlorine in the samples. Conclusion. Thus, an effective UV dose to reduce the concentration of monochloramines in water with a concentration of active chlorine of 0.5 mg/l is 80 mJ/cm2. However, standard UV equipment used for disinfection of pool water cannot guarantee a reduction of chloramine concentration as it is usually designed for the minimum required UV dose (25-40 mJ/cm2). In addition, the effect of UV at this dose on water with a high content of active chlorine led to a significant increase in the content of dichloramines, which is supposedly associated with the destruction of proteins in water under the influence of UV radiation and the subsequent reaction of amino acids with active chlorine.

Influence of UV radiation on the transformation of mono- and dichloramines in water of swimming pools in full-scale tests and in the experiment

2020 ◽  
Vol 99 (3) ◽  
pp. 230-234
Author(s):  
З.И. I. Жолдакова ◽  
Яна Ивановна Лебедь-Шарлевич ◽  
Н.И. I. Беляева ◽  
Р.А. A. Мамонов
Keyword(s):  
Uv Radiation ◽  
Active Chlorine ◽  
Swimming Pools ◽  
Subsequent Reaction ◽  
Uv Treatment ◽  
Pool Water ◽  
Before And After ◽  
Aquarium Water ◽  
Uv Dose ◽  
Full Scale Tests

Introduction. The use of chlorine-containing reagents for disinfection of water in swimming pools may lead to the formation of chloramines, both worsening the organoleptic properties of water and affecting the health of swimmers. To reduce the content of chloramines in pool water, UV radiation can be used. The aim of work is investigation of the effect of UV radiation on the transformation of mono- and dichloramines in water. Material and methods. The study was conducted on water samples from children’s pools, as well as in a model experiment on aquarium water with sodium hypochlorite added. Samples were irradiated with ultraviolet at doses of 40, 80 and 120 mJ/cm2. Before and after UV treatment, the content of chloramines was determined in all samples. Results. UV dose 40 mJ/cm2 was found to be insufficient for the destruction of mono- and dichloramine in water. During UV treatment with a dose 80 mJ/cm2 a decrease in the content of monochloramines and an increase in the content of dichloramines were observed. These processes were depended on the initial concentration of active chlorine in the samples. Conclusion. Thus, an effective UV dose to reduce the concentration of monochloramines in water with a concentration of active chlorine of 0.5 mg/l is 80 mJ/cm2. However, standard UV equipment used for disinfection of pool water cannot guarantee a reduction of chloramine concentration as it is usually designed for the minimum required UV dose (25-40 mJ/cm2). In addition, the effect of UV at this dose on water with a high content of active chlorine led to a significant increase in the content of dichloramines, which is supposedly associated with the destruction of proteins in water under the influence of UV radiation and the subsequent reaction of amino acids with active chlorine.

Study on Marine Bacteria Inactivation by UV Radiation Combined with Multi-pore Ceramic Filtration

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Manxia Zhang ◽  
Xiaojia Tang ◽  
Xiaomei Wu ◽  
Na Li ◽  
Ran Yu ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Marine Bacteria ◽  
Transmission Rate ◽  
Economic Feasibility ◽  
Uv Treatment ◽  
Experimental Conditions ◽  
Bacteria Inactivation ◽  
Low Efficiency ◽  
Uv Dose ◽  
Ceramic Filtration

AbstractUV is one of well-established ways to deal with bacteria in water. However, when applying on marine bacterium inactivation in ballast water, it shows low efficiency due to the existence of large amounts of plankton. To recover high transmission rate of seawater, plankton are required to be removed before UV radiation. Considering technical and economic feasibility, a novel method of multi-pore ceramic filtration (MPCF) is used as a primary treatment before UV radiation. The study compared UV treatment with MPCF & UV treatment at different flow rates and alga concentrations. The results showed that less than 40% marine bacteria can be inactivated by single UV radiation for the existence of large amounts of algae, while up to 100% inactivation rates were observed by MPCF & UV treatment at high alga concentration. According to the results of orthogonal tests, optimal experimental conditions including UV dose were detected. With the combination of MPCF, lethal UV dose for marine bacteria inactivation can reduce to 8 mW·s·cm

UV Irradiation of Shell Eggs: Effect on Populations of Aerobes, Molds, and Inoculated Salmonella typhimurium

1997 ◽  
Vol 60 (6) ◽  
pp. 639-643 ◽  
Author(s):  
FUENG-LIN KUO ◽  
JOHN B. CAREY ◽  
STEVEN C. RICKE
Keyword(s):  
Salmonella Typhimurium ◽  
Uv Radiation ◽  
Uv Light ◽  
The Other ◽  
Uv Exposure ◽  
Microbial Populations ◽  
Aerobic Bacteria ◽  
Fluorescent Light ◽  
Uv Treatment ◽  
Shell Eggs

The effects were investigated of 254-nm UV radiation on populations of Salmonella typhimurium, aerobes, and molds on the shells of eggs. In the first experiment, the CFU of attached S. typhimurium cells on unwashed clean shell eggs were determined after 0, 1, 3, 5, and 7 min of UV treatment (620 μW/cm2) on both ends of the egg. All UV treatments significantly reduced S. typhimurium CFU (P < .01). UVtreatment (620 μW/cm2) in 1-min alternating light and dark cycles for 5 min (three light and two dark) was compared to 0, 3, and 5 min of UV treatment. No significant differences in microbial populations were observed among light and dark cycles and the other UV treatments. In a subsequent experiment, the same UV treatments were utilized to evaluate photoreactivation. After UV exposure, eggs were exposed to 1 h of fluorescent light or I h of darkness or cultured immediately. S. typhimurium CFU were significantly (P < .01) reduced by the UV treatments. However, no significant differences between microbial populations exposed to UV treatment and UV radiation plus photoreactivation were detected. For studies of aerobic bacteria and molds, different UV treatment times (0, 15, and 30 min) at the intensity of 620 μW/cm2 and different intensities (620, 1350, and 1720 μW/cm2) for 15 min were evaluated. Mold CFU per egg were either 0 or 1 for all UV treatments and a 99% reduction of CFU of aerobic bacteria per egg were observed for all UV treatments. It appears from these studies that UV light can significantly reduce populations of S. typhimurium, aerobes, and molds on shell eggs.

Multiple Keratoacanthomas Arising Post-UVB Therapy

2004 ◽  
Vol 8 (4) ◽  
pp. 239-243 ◽  
Author(s):  
Kenneth J. Craddock ◽  
Jaggi Rao ◽  
Gilles J. Lauzon ◽  
Victor A. Tron
Keyword(s):  
Adverse Effect ◽  
Squamous Cell Carcinoma ◽  
Skin Cancer ◽  
Cell Carcinoma ◽  
Uv Radiation ◽  
Squamous Cell ◽  
Etiologic Agent ◽  
Etiologic Factor ◽  
Uv Treatment ◽  
Uvb Phototherapy

Background: Ultraviolet (UV) radiation is known to be an important etiologic agent in the development of skin cancer. Keratoacanthoma is an unusual, well-described cutaneous neoplasm that resembes squamous cell carcinoma but spontaneously resolves. Rarely, multiple keratoacanthomas may develop. Objective We present a case of multiple keratoacanthomas in a patient with psoriasis who had received UVB phototherapy. These lesions were hyperkeratotic papules, many of which spontaneously resolved and demonstrated the histologic characteristics of keratoacanthoma. Conclusion: We believe that UV radiation is the most likely etiologic factor in this patient's development of multiple keratoacanthomas. We wish to bring to the attention of clinicians this unusual adverse effect of UV treatment.

scholarly journals Vegetable Tannin as a Sustainable UV Stabilizer for Polyurethane Foams

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 480 ◽  
Author(s):  
Maria Oliviero ◽  
Mariamelia Stanzione ◽  
Marco D’Auria ◽  
Luigi Sorrentino ◽  
Salvatore Iannace ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Uv Radiation ◽  
Polyurethane Foams ◽  
Accelerated Weathering ◽  
Polyphenolic Compound ◽  
Uv Treatment ◽  
Blowing Agent ◽  
Performance Change ◽  
Urethane Linkage ◽  
Vegetable Tannin

A vegetable tannin, a flavonoid-type natural polyphenolic compound, was used to promote the stabilization of polyurethane foams against UV radiation. Several polyurethane foams were synthesized by using an isocyanate, and a mixture of ethoxylated cocoalkyl amine and vegetable tannin. The content of vegetable tannin was varied from 0 to 40 wt %. The effects of tannin and water (used as a blowing agent) on the foaming kinetics and cellular morphology of foams were investigated. Samples were subjected to accelerated weathering under UV radiation for 3 to 24 h, and FTIR and DMA analyses were conducted to assess the performance change. The former analysis revealed a strong inhibiting effect of tannin on urethane linkage degradation during the UV treatment. The mechanical properties were significantly affected by the addition of tannin. The capability of the foams to withstand UV radiation was dependent on the amount of tannin. At tannin contents higher than 20%, the decrease in mechanical properties under UV irradiation was almost avoided.

scholarly journals The Puncture and Water Resistance of Polyurethane- Impregnated Fabrics after UV Weathering

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 15
Author(s):  
Antonella Patti ◽  
Domenico Acierno
Keyword(s):  
Experimental Data ◽  
Uv Radiation ◽  
Water Resistance ◽  
Uv Light ◽  
Crosslinking Agent ◽  
Waterborne Polyurethane ◽  
Impregnation Method ◽  
Polyurethane Dispersion ◽  
Spectroscopic Analyses ◽  
Before And After

Polyurethane is a polymer adaptable to different scientific and industrial requirements; nevertheless it is also extremely susceptible to UV radiation, which compromises the physical and mechanical functionality. In this framework, our study investigated the effect of waterborne polyurethane dispersion (WPUD) applied to a polyester (PET)-based fabric, through the impregnation method, on the puncturing and water resistance of the pristine material, before and after UV weathering. Results confirmed an increment of both features in the prepared fabrics, attributed to the PUR textile treatment; but a partially loss of the gained properties in the samples due to the UV weathering. In order to improve the efficiency of the impregnating dispersions, in protecting the durability of the treated materials, the addition of different UV light stabilizers, or/and of crosslinking agent into WPUD was also tested. From the experimental data, it can be concluded that formulations based on WPUD, containing both the crosslinker and UV organic absorber, have displayed an increment of their perforation and water resistance for the treated samples with respect to the starting textile, and contemporary have preserved the features against the UV light. Finally, microscopic and spectroscopic analyses have been performed as further characterization techniques of the samples surface.

Removal methods of nematoda contained in the effluent of activated carbon

2002 ◽  
Vol 2 (3) ◽  
pp. 183-190 ◽  
Author(s):  
N. Matsumoto ◽  
T. Aizawa ◽  
S. Ohgaki ◽  
T. Hirata ◽  
K. Toyooka ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Ultraviolet Radiation ◽  
Uv Radiation ◽  
21St Century ◽  
Chlorine Dioxide ◽  
Membrane Filtration ◽  
Sand Filtration ◽  
Uv Dose ◽  
Physical Treatments

Effects of various alternative disinfectants, e.g. chlorine dioxide, ozone, ultraviolet radiation and chloramine, either alone or in combination with other physical treatments like sand filtration and membrane filtration, on the inactivation and removal of nematoda were studied. Ozone and chloramines were found to be effective for nematoda inactivation. Filtration alone was unable to remove nematoda completely. But the combination of UV radiation and sand filtration turned out to be very effective in the removal of nematoda from drinking water. 90% inactivation of nematoda needed a UV dose of (D10-value) 135 mJ/cm2, while 99% inactivation required 232.5 (135 + 97.5) mJ/cm2. This study was a part of a five-year national research project “Advanced Aqua Clean Technology for 21st Century” (ACT21).

scholarly journals Comparison of BGM and PLC/PRC/5 Cell Lines for Total Culturable Viral Assay of Treated Sewage

2008 ◽  
Vol 74 (9) ◽  
pp. 2583-2587 ◽  
Author(s):  
Roberto A. Rodríguez ◽  
Patricia M. Gundy ◽  
Charles P. Gerba
Keyword(s):  
Activated Sludge ◽  
Cell Lines ◽  
Uv Light ◽  
Treatment Plant ◽  
High Rate ◽  
Uv Treatment ◽  
Cell Monolayers ◽  
Reverse Transcription Pcr ◽  
Treated Sewage ◽  
Before And After

ABSTRACT The objective of this study was to compare PLC/PRF/5 and BGM cell lines for use in a total culturable viral assay (TCVA) of treated sewage effluents. Samples were collected before and after chlorination from an activated sludge wastewater treatment plant and from the effluent of a high-rate enhanced flocculation system, followed by UV light disinfection. Cell monolayers were observed for cytopathic effect (CPE) after two passages of 14 days each. Monolayers exhibiting viral CPE were tested for the presence of adenoviruses and enteroviruses by PCR or reverse transcription-PCR. Eight percent of the samples exhibited CPE on BGM cells, and 57% showed CPE on PLC/PRF/5 cells. Only enteroviruses were detected on the BGM cells, while 30% and 52% of the samples were positive for enteroviruses and adenoviruses, respectively, on the PLC/PRF/5 cells. Thirty percent of the samples were positive for both adenoviruses and enteroviruses in chlorinated activated sludge effluent. Thirty percent of the samples were positive for adenoviruses in the UV treatment effluent, but no enteroviruses were detected. In conclusion, the PLC/PRF/5 cells were more susceptible than BGM cells to viruses found in treated sewage. The use of BGM cells for TCVA may underestimate viral concentration in sewage effluent samples. The PLC/PRF/5 cells were more susceptible to adenoviruses, which is important in the evaluation of UV disinfection systems because adenoviruses are highly resistant to UV inactivation.

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