Journal articles: 'Uv treatment'

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Prasetyaningrum, Aji, Widayat Widayat, Bakti Jos, Yudhy Dharmawan, and Ratnawati Ratnawati. "UV Irradiation and Ozone Treatment of κ-Carrageenan: Kinetics and Products Characteristics." Bulletin of Chemical Reaction Engineering & Catalysis 15, no. 2 (March 13, 2020): 319–30. http://dx.doi.org/10.9767/bcrec.15.2.7047.319-330.

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The low molecular weight (LMW) of sulfated polysaccharides including k-carrageenan, is shows a wide spectrum of biological activities. This research investigates the influence of UV irradiation, ozone (O3), and the combination of O3/UV methods on the depolymerization of k-carrageenan. The depolymerization kinetics of k-carrageenan using the Advanced Oxidation Process (UV/O3) was also studied. Furthermore, the intrinsic viscosity method was used to determine the average molecular weight of the research sample, and a mathematical model was developed to predict the kinetic rate constant, as a function of ozone dosage and UV irradiation intensity. Therefore, the physicochemical and morphological properties of the degraded k-carrageenan were analyzed by FT-IR, SEM, and XRD. The intrinsic viscosity k-carrageenan decreases with increasing UV light intensity and ozone concentration. The combination of UV/O3 treatment appeared to be more effective than the individual approaches, as the highest kinetic rate constant for depolymerization was 1.924×10-4 min-1, using 125 mg/L ozone concentration and 40 mW/cm2 of UV lamp intensity. This research also evaluated the relationship between various experimental conditions, including UV lamp power dissipation and ozone concentration on the reaction kinetics model, and the results suggest that lower effect is contributed by UV irradiation intensity. In addition, FT-IR spectra showed the absence of any significant change in the functional properties of k-carrageenan treated with UV and O3 processes, although the morphological properties of the LMW k-carrageenan were rougher and more porous than the native k-carrageenan. Copyright © 2020 BCREC Group. All rights reserved

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KURIHARA, Yuichi, and MASUTAKA Furue. "Carcinogenic Risk of UV Treatment." Nishi Nihon Hifuka 75, no. 3 (2013): 197–99. http://dx.doi.org/10.2336/nishinihonhifu.75.197.

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Bozzi, A., A. Lopez, G. Mascolo, and G. Tiravanti. "Pharmaceuticals degradation by UV and UV/H2O2 treatments." Water Supply 2, no. 2 (April 1, 2002): 19–26. http://dx.doi.org/10.2166/ws.2002.0041.

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The degradation by UV and UV/H2O2 treatments of the pharmaceutical intermediate 5-methyl-1,3,4-thiadiazole-2-methylthiol (MMTD-Me) has been investigated and compared to that of its parent compound [5-methyl-1,3,4-thiadiazole-2-thiol (MMTD)] previously studied. The investigation has been carried out with a 17 W low pressure mercury lamp, at room temperature, with an initial MMTD-Me concentration of 1 mg/l and with a molar ratio H2O2/substrate of 100/1. The results show that: (i) the complete MMTD-Me removal is achieved within 60 and 20 minutes by UV and UV/H2O2 treatment respectively; (ii) the UV only irradiation does not cause any MMTD-Me mineralization; (iii) the UV/H2O2 treatment, after 4 hours, leads to a complete mineralization of MMTD-Me organic sulfur and to a partial mineralization of carbon and nitrogen (79 and 16% respectively). Degradation by-products identification, performed by HPLC-UV-MS, revealed that the UV only irradiation gives rise to the sequential transformation of MMTD-Me into two by-products one of which, the last one, accumulates in the solution. Conversely, the UV/H2O2 treatment leads to the formation of two intermediate by-products that undergo further degradation with the breakdown of the thiadiazole ring. These results confirm the effectiveness of UV based processes, alone or in combination with H2O2, in degrading pharmaceutical intermediates.

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Luiz, D. B., A. K. Genena, H. J. José, R. F. P. M. Moreira, and H. Fr Schröder. "Tertiary treatment of slaughterhouse effluent: degradation kinetics applying UV radiation or H2O2/UV." Water Science and Technology 60, no. 7 (October 1, 2009): 1869–74. http://dx.doi.org/10.2166/wst.2009.583.

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In some Brazilian regions, surface water has become scarce, e.g. semi arid climate areas and densely populated and industrial areas, where water over-exploitation and/or fluvial pollution has been more common. Advanced oxidative processes (AOP) provide treated water as a source of reuse water even with the characteristics of drinking water enabling water reuse practices also in food industries. The secondary wastewater of a slaughterhouse was the water source for a tertiary treatment study evaluating the kinetics of the photo-induced degradation of color and UV254 under UV radiation with and without the addition of H2O2. The proximity of the k′ values of color and UV254 degradation by UV indicates that the compounds responsible for color may be the same content measured by UV254. The H2O2/UV treatment was 5.2 times faster than simple UV in removing aromatic compounds. The degradation kinetics of aromatic compounds in both treatments followed a pseudo-first order law. The pseudo-first order constant for H2O2/UV and UV treatments were kUV254′=0.0306 min−1 and kUV254′=0.0056 min−1, respectively.

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Michod, R. E., M. F. Wojciechowski, and M. A. Hoelzer. "DNA repair and the evolution of transformation in the bacterium Bacillus subtilis." Genetics 118, no. 1 (January 1, 1988): 31–39. http://dx.doi.org/10.1093/genetics/118.1.31.

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Abstract The purpose of the work reported here is to test the hypothesis that natural genetic transformation in the bacterium Bacillus subtilis has evolved as a DNA repair system. Specifically, tests were made to determine whether transformation functions to provide DNA template for the bacteria] cell to use in recombinational repair. The survivorship and the homologous transformation rate as a function of dose of ultraviolet irradiation (UV) was studied in two experimental treatments, in which cells were either transformed before (DNA-UV), or after (UV-DNA), treatment with UV. The results show that there is a qualitative difference in the relationship between the survival of transformed cells (sexual cells) and total cells (primarily asexual cells) in the two treatments. As predicted by the repair hypothesis, in the UV-DNA treatment, transformed cells had greater average survivorship than total cells, while in the DNA-UV treatment this relationship was reversed. There was also a consistent and qualitative difference between the UV-DNA and DNA-UV treatments in the relationship between the homologous transformation rate (transformed cells/total cells) and UV dosage. As predicted by the repair hypothesis, the homologous transformation rate increases with UV dose in the UV-DNA experiments but decreases with UV dose in the DNA-UV treatments. However, the transformation rate for plasmid DNA does not increase in a UV-DNA treatment. These results support the DNA repair hypothesis for the evolution of transformation in particular, and sex generally.

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Hann, Seung Kyung, Moo Yon Cho, and Yoon-Kee Park. "UV Treatment of Generalized Prurigo Nodularis." International Journal of Dermatology 29, no. 6 (July 1990): 436–37. http://dx.doi.org/10.1111/j.1365-4362.1990.tb03833.x.

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Ruzyllo, J., G. T. Duranko, and A. M. Hoff. "Preoxidation UV Treatment of Silicon Wafers." Journal of The Electrochemical Society 134, no. 8 (August 1, 1987): 2052–55. http://dx.doi.org/10.1149/1.2100818.

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MacLeod, Alex J., Qiangyi Li, Carol Bienek, and Peter R. Foster. "UV-C treatment of protein solutions." Biologicals 35, no. 4 (October 2007): 373. http://dx.doi.org/10.1016/j.biologicals.2006.09.003.

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Li, Wei, Liqiang Tan, Yao Zou, Xiaoqin Tan, Jiacheng Huang, Wei Chen, and Qian Tang. "The Effects of Ultraviolet A/B Treatments on Anthocyanin Accumulation and Gene Expression in Dark-Purple Tea Cultivar ‘Ziyan’ (Camellia sinensis)." Molecules 25, no. 2 (January 15, 2020): 354. http://dx.doi.org/10.3390/molecules25020354.

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‘Ziyan’ is a novel anthocyanin-rich tea cultivar with dark purple young shoots. However, how its anthocyanin accumulation is affected by environmental factors, such as ultraviolet (UV), remains unclear. In this study, we observed that UV light treatments stimulated anthocyanin accumulation in ‘Ziyan’ leaves, and we further analyzed the underlying mechanisms at gene expression and enzyme activity levels. In addition, the catechins and chlorophyll contents of young shoots under different light treatments were also changed. The results showed that the contents of total anthocyanins and three major anthocyanin molecules, i.e., delphinidin, cyanidin, and pelargonidin, were significantly higher in leaves under UV-A, UV-B, and UV-AB treatments than those under white light treatment alone. However, the total catechins and chlorophyll contents in these purple tea plant leaves displayed the opposite trends. The anthocyanin content was the highest under UV-A treatment, which was higher by about 66% than control. Compared with the white light treatment alone, the enzyme activities of chalcone synthase (CHS), flavonoid 3′,5′-hydroxylase (F3′5′H), and anthocyanidin synthase (ANS) under UV treatments increased significantly, whereas the leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR) activities reduced. There was no significant difference in dihydroflavonol 4-reductase (DFR) activity under all treatments. Comparative transcriptome analyses unveiled that there were 565 differentially expressed genes (DEGs) of 29,648 genes in three pair-wise comparisons (white light versus UV-A, W vs. UV-A; white light versus UV-B, W vs. UV-A; white light versus UV-AB, W vs. UV-AB). The structural genes in anthocyanin pathway such as flavanone 3-hydroxylase (F3H), F3′5′H, DFR, and ANS, and regulatory gene TT8 were upregulated under UV-A treatment; F3′5′H, DFR, ANS, and UFGT and regulatory genes EGL1 and TT2 were upregulated under UV-AB treatment. However, most structural genes involved in phenylpropanoid and flavonoid pathways were downregulated under UV-B treatment compared with control. The expression of LAR and ANR were repressed in all UV treatments. Our results indicated that UV-A and UV-B radiations can induce anthocyanin accumulation in tea plant ‘Ziyan’ by upregulating the structural and regulatory genes involved in anthocyanin biosynthesis. In addition, UV radiation repressed the expression levels of LAR, ANR, and FLS, resulting in reduced ANR activity and a metabolic flux shift toward anthocyanin biosynthesis.

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Angeles Amaro-Soriano, Fernando Hernández-Aldana, and Antonio Rivera. "Photochemical treatments (UV/H2O2, UV/O3 and UV/H2O2/O3) and inverse osmosis in wastewater: Systematic review." World Journal of Advanced Research and Reviews 10, no. 2 (May 30, 2021): 229–40. http://dx.doi.org/10.30574/wjarr.2021.10.2.0231.

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Every year, the bodies of water receive millions of cubic meters of wastewater from municipal, industrial, agricultural or livestock discharges, treated in an inadequate way or without treatment. The objective of this study was to carry out a systematic review of the frequency of use and effectiveness of the main photochemical processes and the complementation with other treatments such as it is reverse osmosis, used in different types of wastewater effluents. We searched multiple electronic databases (2010-2021), using a stepwise searching approach, supplemented with hand searching. In vitro or in vivo English language publications, original studies, and reviews were included. The database was made up of a total of 100 articles that met the minimum selection criteria, of which 25 articles the maximum scores for analysis. These articles report the improvement in the elimination of pollutants when the treatments are used together and not individually, in relatively short times ranging from 30 minutes of radiation to 8 minutes of exposure to the treatments. Regarding the type of water that was treated, most of the articles report the decontamination of natural wastewater, that is, from the industry without treatment. The percentages calculated to identify research opportunities or gaps in relation to photochemical processes (UV/H2O2/O3). As proposed some authors, if any value of the percentage of pre-selected articles (PAA %) is less than the value of the percentage of failure (MAPAA %), a research opportunity is revealed not addressed by the literature. Based on the percentage results, it is observed that there are no gaps with respect to the photochemical processes or that there are possibly no updates reported in the literature yet.

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KUO, FUENG-LIN, JOHN B. CAREY, and STEVEN C. RICKE. "UV Irradiation of Shell Eggs: Effect on Populations of Aerobes, Molds, and Inoculated Salmonella typhimurium." Journal of Food Protection 60, no. 6 (June 1, 1997): 639–43. http://dx.doi.org/10.4315/0362-028x-60.6.639.

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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.

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Loc, Dang Thi Thanh, Le Van Tuan, Hidenori Harada, Duong Van Hieu, Pham Khac Lieu, and Duong Thanh Chung. "ENHANCEMENT OF WATER DISINFECTION EFFICIENCY USING UV RADIATION WITH THE AID OF A LIQUID-FILM-FORMING DEVICE." Vietnam Journal of Science and Technology 58, no. 3A (May 25, 2020): 203. http://dx.doi.org/10.15625/2525-2518/58/3a/14420.

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This study presents results for the use of UV radiation and a liquid-film-forming device (LFFD) for disinfection of water. Escherichia coli was used as a model microorganism for examining the bactericidal performance of UV. Bacterial inactivation was conducted in a LFFD with various condition of UV dosages, air flow rates, and initial bacterial concentrations. Combined UV/LFFD treatments resulted in a greater inactivation efficiency than those for the UV treatment alone. Combined treatment with UV (UV dosage = 3.020×10-20 kJ/m2, initial bacterial concentration = 1.1×105 – 2.2×105 CFU/mL, and room temperature) and LFFD (air flow rate = 2400 L/min) caused 89% inactivation in terms of the bacterial load. In contrast, when the UV treatment was used, only 29% of the E. coli load was inactivated. These findings suggest that the combined UV/LFFD treatments could provide a promising method for water disinfection.

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Gouma, M., E. Gayán, J. Raso, S. Condón, and I. Álvarez. "UV-Heat Treatments for the Control of Foodborne Microbial Pathogens in Chicken Broth." BioMed Research International 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/436030.

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This investigation established the process criteria for using UV-C light and mild heat (UV-H treatment) to inactivate 5-Log10cycles (performance criterion) of common foodborne pathogen populations,Escherichia coli,SalmonellaTyphimurium,Listeria monocytogenes, andStaphylococcus aureus, when inoculated in chicken broth. To define the target microorganism and the proper UV-H treatment conditions (including UV dose, treatment time, and temperature) that would achieve the stated performance criterion, mathematical equations based on Geeraerd’s model were developed for each microorganism. For the sake of comparison, inactivation equations for heat treatments were also performed on the same chicken broth and for the same microorganisms.L. monocytogeneswas the most UV-H resistant microorganism at all temperatures, requiring a UV dose between 6.10 J/mL (5.6 min) and 2.26 J/mL (2.09 min) to achieve 5-Log10reductions. In comparison with UV treatments at room temperatures, the combination of UV and mild heat allowed both the UV dose and treatment time to be reduced by 30% and 63% at 55°C and 60°C, respectively. Compared to heat treatments, the UV-H process reduced the heating time for 5-Log10reductions of all the investigated microorganisms in chicken broth from 20-fold to 2-fold when the operating temperature varied from 53 to 60°C.

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Qureshi, Tahir Imran, and Young-Ju Kim. "UV-OXIDATIVE TREATMENT OF BIO-REFRACTORY ORGANIC HALOGENS IN LEACHATE: Comparison Between UV/O3, UV/H2O2, and UV/H2O2/O3Processes." Environmental Engineering Research 11, no. 2 (April 30, 2006): 84–90. http://dx.doi.org/10.4491/eer.2006.11.2.084.

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Xie, Yajing, Qiong Lin, Wenqiang Guan, Shuzhen Cheng, Zhidong Wang, and Chongde Sun. "Comparison of Sodium Acid Sulfate and UV-C Treatment on Browning and Storage Quality of Fresh-Cut Potatoes." Journal of Food Quality 2017 (2017): 1–7. http://dx.doi.org/10.1155/2017/5980964.

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Fresh-cut vegetables, such as potato chips, get brown quickly and can easily be infected by bacterium during storage. Sodium acid sulfate (SAS) and UV-C treatments are regarded as effective methods for food preservation. In this study, the effects of SAS, UV-C treatment, and their combination on fresh-cut potatoes during storage were evaluated. Compared with the control, all of the treatments were effective in inhibiting the bacterial growth during the whole storage period. Also, both SAS and SAS + UV-C treatments significantly decreased browning and polyphenol oxidase (PPO) activity and increased the firmness and malondialdehyde (MDA) contents, while the UV-C treatment has no good effects on protecting such storage qualities in fresh-cut potatoes. However, when compared with SAS treatment, the combination of SAS and UV-C treatment did not promote the effect in protecting the storage abilities. Thus, it was concluded that SAS is a better treatment in extending shelf life and controlling the quality of fresh-cut potatoes during storage compared to UV-C treatment.

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Lee, Jin-Hui, Min Cheol Kwon, Eun Sung Jung, Choong Hwan Lee, and Myung-Min Oh. "Physiological and Metabolomic Responses of Kale to Combined Chilling and UV-A Treatment." International Journal of Molecular Sciences 20, no. 19 (October 8, 2019): 4950. http://dx.doi.org/10.3390/ijms20194950.

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Short-term abiotic stress treatment before harvest can enhance the quality of horticultural crops cultivated in controlled environments. Here, we investigated the effects of combined chilling and UV-A treatment on the accumulation of phenolic compounds in kale (Brassica oleracea var. acephala). Five-week-old plants were subjected to combined treatments (10 °C plus UV-A LED radiation at 30.3 W/m2) for 3-days, as well as single treatments (4 °C, 10 °C, or UV-A LED radiation). The growth parameters and photosynthetic rates of plants under the combined treatment were similar to those of the control, whereas UV-A treatment alone significantly increased these parameters. Maximum quantum yield (Fv/Fm) decreased and H2O2 increased in response to UV-A and combined treatments, implying that these treatments induced stress in kale. The total phenolic contents after 2- and 3-days of combined treatment and 1-day of recovery were 40%, 60%, and 50% higher than those of the control, respectively, and the phenylalanine ammonia-lyase activity also increased. Principal component analysis suggested that stress type and period determine the changes in secondary metabolites. Three days of combined stress treatment followed by 2-days of recovery increased the contents of quercetin derivatives. Therefore, combined chilling and UV-A treatment could improve the phenolic contents of leafy vegetables such as kale, without growth inhibition.

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Rosenfeldt, Erik J., Barbara Melcher, and Karl G. Linden. "UV and UV/H2O2 treatment of methylisoborneol (MIB) and geosmin in water." Journal of Water Supply: Research and Technology-Aqua 54, no. 7 (November 2005): 423–34. http://dx.doi.org/10.2166/aqua.2005.0040.

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Gayán, E., M. J. Serrano, J. Raso, I. Álvarez, and S. Condón. "Inactivation of Salmonella enterica by UV-C Light Alone and in Combination with Mild Temperatures." Applied and Environmental Microbiology 78, no. 23 (September 21, 2012): 8353–61. http://dx.doi.org/10.1128/aem.02010-12.

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ABSTRACTThe aim of this investigation was to study the efficacy of the combined processes of UV light and mild temperatures for the inactivation ofSalmonella entericasubsp.entericaand to explore the mechanism of inactivation. The doses to inactivate the 99.99% (4D) of the initial population ranged from 18.03 (Salmonella entericaserovar Typhimurium STCC 878) to 12.75 J ml−1(Salmonella entericaserovar Enteritidis ATCC 13076). The pH and water activity of the treatment medium did not change the UV tolerance, but it decreased exponentially by increasing the absorption coefficient. An inactivating synergistic effect was observed by applying simultaneous UV light and heat treatment (UV-H). A less synergistic effect was observed by applying UV light first and heat subsequently. UV did not damage cell envelopes, but the number of injured cells was higher after a UV-H treatment than after heating. The synergistic effect observed by combining simultaneous UV and heat treatment opens the possibility to design combined treatments for pasteurization of liquid food with high UV absorptivity, such as fruit juices.

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Liu, Kun, Eunyoung Park, Karen M. Mancl, Jiyoung Lee, and Olli H. Tuovinen. "Batch UV Disinfection for Small Flow Onsite Wastewater Treatment." Applied Engineering in Agriculture 36, no. 5 (2020): 717–25. http://dx.doi.org/10.13031/aea.13398.

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HighlightsThe onsite batch UV disinfection system has potential to replace traditional flow-through system.Advantages of UV batch UV system include lamp life savings and controlled dosage by controlling re-circulation time.Higher re-circulation flow rate within batch UV system does not improve disinfection performance.Batch UV system saves energy compared to flow-through system when daily circulation time can be designed for less than 2.5 hours.Abstract. Many small flow and residential wastewater generators are not connected to centralized treatment facilities. Decentralized wastewater treatment systems require effluent disinfection to minimize the public health hazard associated with onsite reuse of the water. The objective of this study was to investigate the performance of an onsite batch UV disinfection system for reuse of wastewater. The field tests were performed with residential wastewater that was treated by septic tank and peat filtration before UV disinfection. E. coli counts were reduced by 1.4 log after 2.5 h contact time. Circulation flow rates did not affect the disinfection efficacy. UV batch disinfection, with hours of operation, has potential to significantly inactivate pathogens but needs site-specific optimization for daily onsite wastewater treatment. Keywords: Clostridium perfringens, Coliphages, Escherichia coli, Onsite wastewater, UV disinfection, Wastewater reuse.

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Silva, Sónia, Conceição Santos, João Serodio, Artur M. S. Silva, and Maria Celeste Dias. "Physiological performance of drought-stressed olive plants when exposed to a combined heat–UV-B shock and after stress relief." Functional Plant Biology 45, no. 12 (2018): 1233. http://dx.doi.org/10.1071/fp18026.

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Climate change scenarios increase the frequency of combined episodes of drought, heat and high UV radiation, particularly in the Mediterranean region where dryland farming of olive (Olea europaea L.) orchards remains a common practice. Nonirrigated olive plants (drought treatment) were subjected to an episode of heat plus UV-B radiation shock (DH+UV-B treatment) for 2 days. After the treatments, plants were allowed to grow under irrigated conditions (recovery). Compared with irrigated plants, drought treatment induced lower relative water content but this status was not aggravated when DH+UV-B shock was applied. Additionally, the effective quantum yield of PSII was similar in the drought-stressed and DH+UV-B treatments. Interestingly, the DH+UV-B treatment produced higher photosynthetic pigment contents than drought-stressed plants. Concerning oxidative status, the DH+UV-B treatment induced similar lipid peroxidation levels and only cell membrane permeability was higher than in drought-stressed plants. On other hand, drought-stressed plants showed higher levels of anthocyanins and proline. Our data suggest that plants grown under dryland conditions modulated some tolerance mechanisms that may prevent cumulative damages by other stressors. Moreover, drought-stressed and DH+UV-B plants were able to recover their physiological performance in a similar way. These data represent an important contribution to understanding how dryland -grown olive plants will cope with climate change.

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Kim, Bong-Yong, Akira Isogai, Fumihiko Onabe, and Makoto Usuda. "Degradation mechanism of paper by UV treatment." JAPAN TAPPI JOURNAL 44, no. 2 (1990): 242–48. http://dx.doi.org/10.2524/jtappij.44.242.

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Le, Vinh Xuan, Phung Tieu Ly, and Hien Thi To. "Textile wastewater treatment by UV/Fenton process." Science and Technology Development Journal 18, no. 4 (December 30, 2015): 201–11. http://dx.doi.org/10.32508/stdj.v18i4.950.

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The textile wastewater is one of the most complex wastewaters because it contains many persistant organic compounds. In this study, factors effect on UV/Fenton process were investigated including: concentration of H2O2, Fe2+, initial pH, time reaction and the stirring speed. Raw wastewater was aerated for 24 h and filtered by 20 μm filter paper before conducting reactions. The optimum conditions of the UV/Fenton process were attained at 660 mgH2O2/L and 20 mgFe2+/L, pH 3, 90 min irradiation time and 100 rpm stirring speed. Decolorisation and COD removal efficiencies were achieved 94.2 % and 75.5 %, respectively. The ratio of BOD5/COD was increased from 0.1 to 0.45. In addition, the effects of anions Cl-, SO4 2- on the efficient treatment were investigated. Both anions could inhibit the mineralization process due to scavenging of hydroxyl radical as well as forming strong complexes with iron ions.

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Reckhow, David A., Karl G. Linden, Junsung Kim, Hilla Shemer, and Gladys Makdissy. "Effect of UV treatment on DBP formation." Journal - American Water Works Association 102, no. 6 (June 2010): 100–113. http://dx.doi.org/10.1002/j.1551-8833.2010.tb10134.x.

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Donaghy, J., M. Keyser, J. Johnston, F. P. Cilliers, P. A. Gouws, and M. T. Rowe. "Inactivation ofMycobacterium aviumssp.paratuberculosisin milk by UV treatment." Letters in Applied Microbiology 49, no. 2 (August 2009): 217–21. http://dx.doi.org/10.1111/j.1472-765x.2009.02644.x.

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Nyer, Evan K., and Paul Bitter. "Evaluation of Ultraviolet (UV)-Oxidation Treatment Methods." Groundwater Monitoring & Remediation 11, no. 1 (February 1991): 88–92. http://dx.doi.org/10.1111/j.1745-6592.1991.tb00353.x.

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Holl, S. L., C. A. Colinge, K. D. Hobart, and F. J. Kub. "UV Activation Treatment for Hydrophobic Wafer Bonding." Journal of The Electrochemical Society 153, no. 7 (2006): G613. http://dx.doi.org/10.1149/1.2196673.

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Hodaifa, Gassan. "Treatment of Olive Oil Mill Wastewater by UV-Light and UV/H2O2 System." International Journal of Green Technology 1, no. 1 (February 1, 2018): 46–53. http://dx.doi.org/10.30634/2414-2077.2015.01.5.

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Zwiener, C., L. Weil, and R. Niessner. "Atrazine and Parathion-Methyl Removal by UV And UV/O3in Drinking Water Treatment." International Journal of Environmental Analytical Chemistry 58, no. 1-4 (January 1995): 247–64. http://dx.doi.org/10.1080/03067319508033128.

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Westerhof, Wiete. "Treatment of Vitiligo With UV-B Radiation vs Topical Psoralen Plus UV-A." Archives of Dermatology 133, no. 12 (December 1, 1997): 1525. http://dx.doi.org/10.1001/archderm.1997.03890480045006.

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Westerhof, W. "Treatment of vitiligo with UV-B radiation vs topical psoralen plus UV-A." Archives of Dermatology 133, no. 12 (December 1, 1997): 1525–28. http://dx.doi.org/10.1001/archderm.133.12.1525.

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Maarschalkerweerd, Jan, Rory Murphy, and Gail Sakamoto. "Ultraviolet Disinfection in Municipal Wastewater Treatment Plants." Water Science and Technology 22, no. 7-8 (July 1, 1990): 145–52. http://dx.doi.org/10.2166/wst.1990.0240.

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Pilot and full-scale studies of UV disinfection of wastewater have demonstrated that the process could consistently meet an effluent fecal coliform standard of 200/100 mL or less, depending on suspended solids and UV transmission. Since 1984 over three hundred systems have been installed at municipal wastewater treatment plants in North America. The majority of these are in treatment plants which have been using chlorination. The UV systems have been retrofitted into the existing chlorine contact tanks or existing channels. The capital costs of retrofitting compare favourably to the costs of upgrading chlorination systems, especially when de-chlorination equipment is required. As experience is gained in the operation of these UV systems, their performance has been monitored for their disinfection efficiency and cost of operation. Several installations are examined and their performance and costs analyzed. The evidence to date supports the premise that UV disinfection can meet demands for reliable effluent disinfection in a cost effective manner.

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Zhao, Jing, Jiadong Peng, Ran Yin, Mengge Fan, Xin Yang, and Chii Shang. "Multi-angle comparison of UV/chlorine, UV/monochloramine, and UV/chlorine dioxide processes for water treatment and reuse." Water Research 217 (June 2022): 118414. http://dx.doi.org/10.1016/j.watres.2022.118414.

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Constantin, Lucian Alexandru, Mirela Alina Constantin, Ines Nitoi, Toma Galaon, Valeriu Robert Badescu, and Nicolae Ionut Cristea. "COMPARISON OF FLUTAMIDE DEGRADATION VIA UV/TIO2, UV/H2O2 AND UV/H2O2/TIO2 SYSTEMS." Romanian Journal of Ecology & Environmental Chemistry 2, no. 1 (July 31, 2020): 4–10. http://dx.doi.org/10.21698/rjeec.2020.101.

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Synthetic solutions of flutamide were subject to degradation using three advanced oxidation systems, namely UV/TiO2, UV/H2O2 and UV/H2O2/TiO2. Optimum conditions and degradation kinetics has been established for all three systems. The experimental results showed that all three systems can be successfully used for flutamide degradation with efficiencies higher than 99% and that advanced oxidation processes are showing good potential for degradation of organic pollutants that cannot be suitable removed/degraded using conventional wastewater treatment processes.

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Xie, Juan, Xin Qiang Wang, and Cheng Tun Qu. "Study on Treatment to Methanol Wastewater by UV/Fenton." Advanced Materials Research 807-809 (September 2013): 1473–78. http://dx.doi.org/10.4028/www.scientific.net/amr.807-809.1473.

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In this paper, aqueous methanol (methanol concentration 1000 mg·l-1) degradation was studied by using UV/Fenton, and effect of methanol degradation was evaluated with COD removal rate. When pH was determined, H2O2 dosage, Fe2+ dosage and reaction time were investigated by single factor test, respectively. In the orthogonal experiment, UV/Fenton was used to deal with wastewater of 1000 mg·l-1methanol, the order of the influent factors on COD removal was: H2O2 dosage > reaction time > Fe2+ content. Under the optimal condition (6%H2O250 ml·l-1, Fe2+ 0.9 g·l-1, reaction time 60 min), 95.77% COD removal rate was obtained. In addition, a comparison of UV, Fenton regent and UV/Fenton system indicated that UV and Fe2+ had synergistic effect on catalytic decomposition of H2O2, and reaction time to obtain the highest COD removal was shorted 10 min when UV/Fenton was used.

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Li, Peiyang, Jacek A. Koziel, Jeffrey J. Zimmerman, Jianqiang Zhang, Ting-Yu Cheng, Wannarat Yim-Im, William S. Jenks, Myeongseong Lee, Baitong Chen, and Steven J. Hoff. "Mitigation of Airborne PRRSV Transmission with UV Light Treatment: Proof-of-Concept." Agriculture 11, no. 3 (March 18, 2021): 259. http://dx.doi.org/10.3390/agriculture11030259.

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Proper treatment of infectious air could potentially mitigate the spread of airborne viruses such as porcine reproductive and respiratory syndrome virus (PRRSV). The objective of this research is to test the effectiveness of ultraviolet (UV) in inactivating aerosolized PRRSV, specifically, four UV lamps, UV-A (365 nm, both fluorescent and LED-based), “excimer” UV-C (222 nm), and germicidal UV-C (254 nm), were tested. The two UV-C lamps effectively irradiated fast-moving PRRSV aerosols with short treatment times (<2 s). One-stage and two-stage UV inactivation models estimated the UV doses needed for target percentage (%) reductions on PRRSV titer. UV-C (254 nm) dose needed for 3-log (99.9%) reduction was 0.521 and 0.0943 mJ/cm2, respectively, based on one-stage and two-stage models. An order of magnitude lower UV-C (222 nm) doses were needed for a 3-log reduction, i.e., 0.0882 and 0.048 mJ/cm2, based on one-stage and two-stage models, respectively. However, the cost of 222 nm excimer lamps is still economically prohibitive for scaling-up trials. The UV-A (365 nm) lamps could not reduce PRRSV titers for tested doses up to 4.11 mJ/cm2. Pilot-scale or farm-scale testing of UV-C on PRRSV aerosols simulating barn ventilation rates are recommended based on its effectiveness and reasonable costs comparable to HEPA filtration.

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Zhao, Yaqi, Jinhua Zuo, Shuzhi Yuan, Wenlin Shi, Junyan Shi, Bihong Feng, and Qing Wang. "UV-C Treatment Maintains the Sensory Quality, Antioxidant Activity and Flavor of Pepino Fruit during Postharvest Storage." Foods 10, no. 12 (December 2, 2021): 2964. http://dx.doi.org/10.3390/foods10122964.

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This study examines ultraviolet-C (UV-C) treatment supplementation as a means of inhibiting the senescence of pepino fruit after harvest. Pepino fruits were subjected to 1.5 kJ/m2 UV-C treatments and then packed and stored at 10 °C for 28 d. Results showed that 1.5 kJ/m2 UV-C treatment had the greatest ability to maintain firmness, and reduced the level of respiration and ethylene production. Further analysis indicated that the 1.5 kJ/m2 UV-C treatment maintained the content of total soluble solids (TSS), chlorophyll, vitamin C, flavonoids, and total phenolics. Lower levels of malondialdehyde (MDA) and higher levels of antioxidant enzyme activity were found in UV-C treated fruit during storage. An electronic nose (E-nose) and headspace-gas chromatography-mass spectrometry (HS-GC-MS) was used to determine volatile compounds. Results revealed that the UV-C treatment may promote the synthesis of a large number of alcohols and esters by maintaining the overall level of acids, aldehydes, and esters in fruits. This may contribute to the maintenance of the flavor of harvested fruits. In conclusion, 1.5 kJ/m2 UV-C treatment was demonstrated to be an effective treatment for the maintenance of the sensory, nutritional, and flavor parameters of pepino fruit.

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Ovaska, Kristiina, Theodore M. Davis, and Iñigo Novales Flamarique. "Hatching success and larval survival of the frogs Hyla regilla and Rana aurora under ambient and artificially enhanced solar ultraviolet radiation." Canadian Journal of Zoology 75, no. 7 (July 1, 1997): 1081–88. http://dx.doi.org/10.1139/z97-130.

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The aquatic stages of amphibians may be sensitive to increased levels of solar ultraviolet B radiation (UV-B, 280–320 nm) that have been observed at higher latitudes over the past several decades, but the effects on most species are unknown. We exposed eggs and larvae of Hyla regilla and Rana aurora to three experimental treatments: (1) solar UV < 450 nm blocked (control), (2) ambient solar UV, and (3) solar UV-B enhanced 15 and 30% above ambient levels at midday to simulate conditions predicted for the next decades at midlatitudes. The rearing containers were covered with acrylic filters to provide the desired radiation regimes. Hatching success of H. regilla did not differ among the treatments and was 87.7, 71.8, and 87.1% in April 1995 and 94.0, 85.1, and 97.4% in May 1995 for the control, ambient, and enhanced UV-B treatments, respectively. In contrast, hatching success of R. aurora in the enhanced UV-B treatment (56.0%) was lower than in the ambient UV (89.8%) and control (81.0%) treatments. Larval survival over the first 2 months of development was reduced to 18.4% for H. regilla and 2.6% for R. aurora in the enhanced UV-B treatment compared with the ambient UV and control treatments. We conclude that ambient UV levels at the study site did not affect the embryonic or early larval survival of either of the species tested under the experimental conditions, but both species are potentially vulnerable to increases in solar UV-B.

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Linden, Karl G., Jeanette Thurston, Raymond Schaefer, and James P. Malley. "Enhanced UV Inactivation of Adenoviruses under Polychromatic UV Lamps." Applied and Environmental Microbiology 73, no. 23 (October 12, 2007): 7571–74. http://dx.doi.org/10.1128/aem.01587-07.

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ABSTRACT 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.

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Zhang, Ji Ku, Zhi Biao Dong, and Yan Bin Yang. "New Closed UV Sterilizer Application of Wastewater Treatment." Advanced Materials Research 535-537 (June 2012): 2232–35. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.2232.

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Sumarlan, Iwan, Is Fatimah, and Karna Wijaya. "Indonesian Modified Clay for Dye Waste Treatment." Acta Chimica Asiana 3, no. 1 (February 28, 2020): 122. http://dx.doi.org/10.29303/aca.v3i1.11.

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Synthesis and Characterization of TiO2 Coated on Clay Pillared Alumina (PILC) for Methyl Orange Photodegradation Under UV Illumination. The synthesis included both pillarization the clay with alumina and TiO2 coated on PILC using impregnation method. Some characterizations also were employed to this research such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), N2 Adsorption Isotherm and UV-Visible Diffuse Reflectance (DR UV). The photocatalyst was then used to decompose waste dye, methyl orange (MO). Among three photocatalysts that were successfully synthesized, PILC Ti 1.0% had the highest activity to decompose the waste dye.

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Lubello, C., C. Caretti, and R. Gori. "Comparison between PAA/UV and H2O2/UV disinfection for wastewater reuse." Water Supply 2, no. 1 (January 1, 2002): 205–12. http://dx.doi.org/10.2166/ws.2002.0025.

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The effect of peracetic acid (PAA) on indicator bacteria in secondary sewage effluent has shown PAA to be a viable alternative to other biocides. The synergy between UV/PAA and UV/H2O2 in laboratory experiments and at a pilot plant fed by the secondary effluent of two civil wastewater treatment plant has been investigated. This experiment is part of a larger research project on advanced treatment for municipal wastewater reuse in agriculture. A very high level of disinfection is necessary because of Italy's strict limits on unrestricted wastewater reuse in agriculture (2 CFU Total Coliform/100 ml). We found out that a combined treatment is satisfactory and that it is more efficient when chemical products such as PAA or H2O2 are introduced before UV irradiation, taking advantage of the hydroxyl radicals formation due to photolysis. At a cost parity PAA/UV advanced oxidation process shows the same disinfectant action as H2O2/UV while at a dose (amount) and cost parity, PAA shows a significantly better disinfectant action than H2O2.

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Demir, Hande, Mustafa Kemal Yıldız, İsmail Becerikli, Sevcan Unluturk, and Zehra Kaya. "Assessing the impact of non-thermal and thermal treatment on the shelf-life of onion juice." Czech Journal of Food Sciences 36, No. 6 (January 7, 2019): 480–86. http://dx.doi.org/10.17221/163/2018-cjfs.

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Onion (Allium cepa L.) juice is a marinating agent for meat and fish marination and readily usable sauce for any meal that has onion in its formulation. This study aims to assess the microbiological and physicochemical changes in the onion juice processed by UV-C irradiation (0.5 mm sample depth, 30 min exposure time, 7.5 mW/cm<sup>2</sup> UV incident intensity) and conventional heat treatment (74.5°C, 12 min) during its storage. Microbiological results showed processing by UV-C irradiation or heat treatment under optimum conditions extended the microbial shelf-life of untreated onion juice by minimum 6-times. Total colour change of heat-treated samples was lower than that of untreated and UV-C treated samples for 12 weeks. Also, pH, total titratable acidity, total soluble solids content, turbidity, NEBI and total phenolic content were monitored for 12 weeks. The results of this study will form scientific infrastructure for onion juice manufacturers to decide on the processing method with respect to its shelf-life.

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Hollman, Jordan, John Albino Dominic, Gopal Achari, Cooper H. Langford, and Joo-Hwa Tay. "Effect of UV dose on degradation of venlafaxine using UV/H2O2: perspective of augmenting UV units in wastewater treatment." Environmental Technology 41, no. 9 (September 19, 2018): 1107–16. http://dx.doi.org/10.1080/09593330.2018.1521475.

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Ruppert, Gerald, Rupert Bauer, and Günter Heisler. "UV-O3, UV-H2O2, UV-TiO2 and the photo-Fenton reaction - comparison of advanced oxidation processes for wastewater treatment." Chemosphere 28, no. 8 (March 1994): 1447–54. http://dx.doi.org/10.1016/0045-6535(94)90239-9.

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Zhang, Ji Ku, Yang Yang Li, Chen Zhang, and Yan Bin Yang. "Experimental Studies of CS Type UV Sterilizer for the Urban Sewage Treatment." Applied Mechanics and Materials 361-363 (August 2013): 601–5. http://dx.doi.org/10.4028/www.scientific.net/amm.361-363.601.

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By treating the secondary effluent of Sanbaotun sewage treatment plant in Fushun with the CS type UV Sterilizer, the experiment researches the influence on the removal rate which includes the factors of turbidity, chromaticity, initial E.coli concentration of raw water, UV dose. The results show that the turbidity does not influence on UV disinfection efficiency with the turbidity from 1.5NTU to 3.8NTU. In the low-dose UV disinfection process, the influent sewage turbidity should under 4NTU to ensure the disinfection efficiency. Low chromaticity does not affect the UV disinfection efficiency, with the influent sewage chromaticity is under 15 degrees.The initial E. coli has a certain impact on little doses of UV disinfection with the concentration from 175 × 104 A/ L to 230 × 104 A/ L, no impact on high doses of UV disinfection。

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KEKLIK, NENE M., ALI DEMIRCI, PAUL H. PATTERSON, and VIRENDRA M. PURI. "Pulsed UV Light Inactivation of Salmonella Enteritidis on Eggshells and Its Effects on Egg Quality." Journal of Food Protection 73, no. 8 (August 1, 2010): 1408–15. http://dx.doi.org/10.4315/0362-028x-73.8.1408.

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The majority of Salmonella Enteritidis outbreaks have been related to the consumption of raw or undercooked eggs or egg-containing foods. Therefore, the U.S. Department of Agriculture mandates egg washing for all graded eggs by use of a detergent solution and sanitizer. These agencies and the egg industry have been investigating alternative decontamination techniques, which could better serve the public, minimize costs, and benefit both the public and the industry. Pulsed UV light is an emerging technology that is used to inactivate microorganisms quickly. In this study, the effectiveness of pulsed UV light was evaluated for the decontamination of eggshells. Eggs inoculated with Salmonella Enteritidis on the top surface at the equator were treated with pulsed UV light 1 to 30 s, at a distance of 9.5 and 14.5 cm from the UV lamp in a laboratory-scale, pulsed UV light chamber. Three eggs were used per treatment in each repetition, except for quality measurements, which involved six eggs per treatment in each repetition. A maximum log reduction of 5.3 CFU/cm2 was obtained after a 20-s treatment at 9.5 cm below the UV lamp at a total dose of 23.6 ± 0.1 J/cm2, without any visual damage to the egg. After a 30-s treatment at 9.5 and 14.5 cm, the temperature of eggshell surfaces increased by 16.3 and 13.3°C, respectively. Energy usage increased up to 35.3 ± 0.1 and 24.8 ± 0.1 J/cm2, after 30-s treatments at 9.5 and 14.5 cm, respectively. The effect of pulsed UV light treatments on egg quality was also evaluated. Pulsed UV-light treatments for 3, 10, and 20 s at either 9.5 or 14.5 cm did not change the albumen height, eggshell strength, or cuticle presence significantly (P > 0.05). This study demonstrated that pulsed UV light has potential to decontaminate eggshell surfaces.

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Abbas, Mazhar, Sumaira Sharif, Ibrahim Salam Baig, Rimsha Anjum, Muhammad Riaz, Muhammad Kamran Rafique, Abdur Rahman, Nadia Nazish, Samiah H. Al-Mijalli, and Munawar Iqbal. "Biochemical Stress Markers, Antioxidants, and Infectious Wound-Healing Potential of UV Irradiation and Salt Stress Effects on the Pre-Treated Seed of Bitter Melon (Momordica charantia L.)." Dose-Response 19, no. 4 (October 2021): 155932582110440. http://dx.doi.org/10.1177/15593258211044062.

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Purpose The secondary metabolites in plants are the basis of defense and stress balance, which is an important aspect in plant growth. The UV-B treatment (a biotic stress) and salt stress on bitter melon ( Momordica charantia L.) were studied, and the impact of pre-sowing seed treatment was evaluated on the basis of biochemical and enzymatic biomarkers, antioxidants, and wound-healing potential during early growth stages. Methods The UV-B treatment for 5 and 10 min and salt stress 250 mM and 500 mM treatments were applied, and 21-day seedling tissue were collected for total phenolic contents (TPC), total flavonoid contents (TFC), antioxidant, chlorophyll contents, hydrogen peroxide, total soluble sugar, enzymes activities, and wound-healing potential studies. Results The TPC, TFC, diphenyl picrylhydrazyl (DPPH), chlorophyll contents, and total soluble sugar were recorded higher at 5 min treatment with UV-B and salt stress at 250 mM concentration. Antioxidant enzymes activities were recorded higher for 10 min UV-B treatment and 500 mM salt treatment. Wound-healing potential was found significant at 5 min treatment with UV-B radiation, which was studied in vivo in rabbits. The LC-MS analysis revealed a variety of phenolic compounds in the seedlings. Conclusion The study concluded that treatments significantly affect the biological activities of bitter melon seeds at the seedling stage, and the seeds contain important phenolic compounds responsible for its antioxidant potential and enzymatic activities. Future studies could be focused on the later stages of growth, development, and yield characteristics subjected to salt stress along with UV-B radiation treatment.

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Kabdaşlı, Işık, Çisem Ecer, Tugba Olmez-Hanci, and Olcay Tünay. "A comparative study of HO•− and SO4•−-based AOPs for the degradation of non-ionic surfactant Brij30." Water Science and Technology 72, no. 2 (April 30, 2015): 194–202. http://dx.doi.org/10.2166/wst.2015.204.

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In the present study aqueous solutions of Brij30, an alcohol ethoxylate surfactant, were photocatalytically and photochemically treated by employing the TiO2/UV-A, H2O2/UV-C and persulfate (PS)/UV-C processes. During TiO2/UV-A treatment, even in short reaction periods (10 minutes), high rates of Brij30 removals were achieved; however, longer experiment periods (240–480 minutes) were needed in order to obtain notable total organic carbon (TOC) removals. Increasing the TiO2 dosage exhibited a positive effect on treatment efficiencies. For initial pH value of 3.0, increasing the TiO2 dosage from 1.0 to 1.5 g/L resulted in an improvement in Brij30 removal from 64% to 79% after 10 minutes whereas 68 and 88% TOC removals were observed after 480 minutes, respectively. Brij30 removal was very fast and complete via both H2O2/UV-C and PS/UV-C treatments, accompanied with significant mineralization rates ranging between 74 and 80%. Toxicity assessed by Vibrio fischeri, was found to be similar to that of the original Brij30 solution during H2O2/UV-C treatment, while in the PS/UV-C process, the relative inhibition of Brij30 towards V. fischeri fluctuated throughout the treatment and eventually non-toxic products were formed by the oxidation of SO4•− radicals.

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KIM, YOUNGBONG, YOONJUNG CHOI, SOOHYUN KIM, JONGHYUN PARK, MYONGSOO CHUNG, KYUNG BIN SONG, INGYUN HWANG, KISUNG KWON, and JIYONG PARK. "Disinfection of Iceberg Lettuce by Titanium Dioxide–UV Photocatalytic Reaction." Journal of Food Protection 72, no. 9 (September 1, 2009): 1916–22. http://dx.doi.org/10.4315/0362-028x-72.9.1916.

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Securing the physical quality and microbial safety of fresh foods has been a major focus in the food industry. To improve quality and increase the shelf life of fresh produce, disinfection methods have been developed. Titanium dioxide (TiO2) photocatalytic reactions under UV radiation produce hydroxyl radicals that can be used for disinfection of foodborne pathogenic bacteria. We investigated the effects of TiO2-UV photocatalytic disinfection on the shelf life of iceberg lettuce. Counts of natural microflora (total aerobic bacteria, coliforms, psychrotrophic bacteria, and yeasts and molds) and inoculated pathogenic bacteria (Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, and Salmonella Typhimurium) on iceberg lettuce were determined after 20-min treatments with TiO2-UV, UV radiation, a sodium hypochlorite (NaOCl) solution, and tap water. TiO2-UV treatment reduced the number of microorganisms by 1.8 to 2.8 log CFU/g compared with reductions of 0.9 to 1.4 and 0.7 to 1.1 log CFU/g obtained with UV radiation and NaOCl treatments, respectively. Treatment with tap water was used as a control and resulted in no reductions. Counts of microflora for iceberg lettuce at 4 and 25°C were determined during a 9-day period. TiO2-UV treatment resulted in 1.2- and 4.3-log increases in the counts of total aerobic bacteria at 4 and 25°C, respectively, compared with 1.3- to 1.6-log and 4.4- to 4.8-log increases due to UV radiation and NaOCl treatments.

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Kim, I. H., N. Yamashita, Y. Kato, and H. Tanaka. "Discussion on the application of UV/H2O2, O3 and O3/UV processes as technologies for sewage reuse considering the removal of pharmaceuticals and personal care products." Water Science and Technology 59, no. 5 (March 1, 2009): 945–55. http://dx.doi.org/10.2166/wst.2009.076.

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The applicability of O3, UV/H2O2 and O3/UV treatment processes as technologies for water reuse considering pharmaceuticals and personal care products (PPCPs) removal was investigated. Electrical energies required for the effective removal of various PPCPs in secondary effluent were 0.09 kWh/m3, 0.54 kWh/m3 and 1.09 kWh/m3 for O3, UV/H2O2 and O3/UV treatments, respectively, showing that O3 treatment is the most cost-effective treatment option for the PPCPs removal. O3 treatment showed the effective PPCPs removal at O3 dose of 6 mg/L; however, the formation of bromate is expected for O3 treatment using O3 dose of more than 4 mg/L. In particular, bromate formation will be a critical issue when the reclaimed water is used for direct/indirect potable reuses. Therefore, in order to suppress the bromate formation as well as achieve the effective PPCPs removal, O3/UV treatment will be recommended. UV/H2O2 treatment will be also a profitable treatment method because no bromate will be formed during the process. The evaluation for ecological risk of PPCPs by the applied processes showed that all the processes could decrease the ecological risk caused by parent PPCPs considerably. This means that the investigated treatment processes can play an important role in reducing unpredictable side effects caused by PPCPs in the aquatic environment.

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Journal articles on the topic 'Uv treatment'

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