• Environmental Engineering Research
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• 제16권3호
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• pp.131-136
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• 2011

The degradation of 30 pharmaceuticals and personal care products (PPCPs) subjected to $O_3$, $O_3$/UV, and $O_3/H_2O_2$ treatments were investigated using semi-batch tests and evaluated by their pseudo-first-order rate constants. The additional application of UV or $H_2O_2$ during $O_3$ treatment significantly improved the degradation rate of most of the PPCPs. At the same $O_3$ feed rate, $O_3$/UV treatment exhibited much higher PPCP degradation efficiency than that of $O_3$ treatment. This was probably due to degradation of the PPCPs by $O_3$, direct UV photodegradation, and OH radicals that formed from the photodegradation of $O_3$ during $O_3$/UV treatment. PPCP degradation by $O_3$ was also promoted by adding $H_2O_2$ during the $O_3$ treatment. However, when the initial $H_2O_2$ concentration was high during $O_3$ treatment, OH radicals were likely to be scavenged by excess $H_2O_2$, leading to low PPCP degradation. Therefore, it is important to determine the appropriate $H_2O_2$ dosage during $O_3$ treatment to improve PPCP degradation when adding $H_2O_2$ during $O_3$ treatment.

• 한국의류학회지
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• 제34권11호
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• pp.1859-1869
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• 2010

This study provides improved wrinkle recovery and UV protection capabilities as well as an antibacterial and deodorizing function to linen fabrics for summer shirts. The results obtained from this study are as follows. By setting catalyst concentration to 1.2% and DMDHEU concentration to 6% respectively and applying a heat treatment to them at $160^{\circ}C$ for 5 minutes, the decrease of fabric strength could be minimized and the crease resistance of linen fabrics improved. Compared to the treatment with DMDHEU only, the crease resistance of linen fabrics could be maintained and degradation of their properties could be more effectively prevented by applying the mixture of the UV absorber and the nano silver to the DMDHEU resin. The UV protection of fabrics could be improved by adding the UV absorber. Although the separate treatment of resin or the nano silver had no effect on the improvement of the UV protection properties for treated fabrics, they could increase the UV protection capability when they were combined with the UV absorber. Linen fabrics could possess an antibiosis and deodorizing capability by applying the mixture of the UV absorber, the nano silver, and the resin. The UV protection, crease resistance and flexibility of finished fabrics were maintained even after laundering. Washed treated fabrics maintained excellent antibiosis and odor free capabilities compared to untreated fabrics.

• Membrane and Water Treatment
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• 제8권3호
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• pp.211-223
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• 2017

In this work, an attempt was made to compare the effects of UV irradiation on the intrinsic and separation properties of membranes made of two different polymeric materials, i.e., polyvinylidene fluoride (PVDF) and polyetherimide (PEI). The changes on membrane structural morphologies and chemical characteristics upon UV-A exposure (up to 60 h) were studied by FESEM and FTIR, respectively. It was found that cracks and fractures were detected on the PVDF-based membrane surface when the membrane was exposed directly to UV light for up to 60 h. Furthermore, the mechanical strength and thermal stability of irradiated PVDF-based membrane was reported to decrease with increasing UV exposure time. The PEI membrane surface meanwhile remained almost intact throughout the entire UV irradiation process. Filtration experiments showed that the permeate flux of UV-irradiated PVDF membrane was significantly increased from approximately 11 to $16L/m^2.h$ with increasing UV exposure time from zero to 60 h. Oil rejection meanwhile was decreased from 98 to 85%. For the PEI-based membrane, oil rejection of >97% was recorded and its overall structural integrity was marginally affected throughout the entire UV irradiation process. The findings of this work showed that the PEI-based membrane should be considered as the host for photocatalyts incorporation if the membrane was to be used for UV-assisted wastewater treatment process.

• 상하수도학회지
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• 제25권6호
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• pp.861-867
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• 2011

Wastewater from crude oil reserve base usually contains large amount of non-biodegradable contaminants. The conventional wastewater treatment progress can hardly meet the regulation of wastewater effluent quality. This study investigated the removal of non-biodegradable organic contaminants in wastewater from crude oil reserve base using a pulse UV treatment. The modified process incorporating pulse UV process was set up to treat the wastewater from crude oil reserve base. The treatment process is composed with coagulation and flocculation, micro-bubble flotation, sand filter, pulse UV system, and GAC filter. The results show CODMn was effectively removed by the process with pulse UV system and it can meet the wastewater effluent regulation. The single effect of pulse UV process in CODMn removal was not significant(9~15% based on sand filtered effluent), however with the subsequent activated carbon filter the removal ratio CODMn was increased up to 28% compared to the process without pulse UV syetem.

• 한국식품위생안전성학회지
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• 제32권1호
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• pp.64-69
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• 2017

본 연구에서는 양상추에 접종된 E. coli O157:H7, S. Typhimurium과 L. monocytogene에 대하여 저온 플라즈마와 UV-C 단독처리 및 병행처리 효과를 측정하였다. E. coli O157:H7, S. Typhimurium, L. monocytogenes는 양상추에 초기 농도가 5.82, 5.09, 5.65 log CFU/g이 되도록 각각 접종하였다. 저온 플라즈마와 UV-C를 처리된 양상추는 $4^{\circ}C$에서 9일간 보관하며 미생물학적 분석과 관능평가를 실시하였다. 저온 플라즈마 처리는 E. coli O157:H7, S. Typhimurium, L. monocytogenes의 개체 수를 각각 0.26, 0.65, 0.93 log CFU/g 수준으로 감소시켰다. 또한, UV-C 처리 시 각각 0.87, 0.88, 1.14 log CFU/g 수준으로 감소되었다. 또한 UV-C 처리 후 저온 플라즈마를 처리한 병행처리에서는 각각 1.44, 2.70, 1.62 log CFU/g 수준으로 감소하였다. 저온 플라즈마와 UV-C 단독처리 보다는 병행처리가 좀 더 효과적으로 균을 저감하는 것으로 판단되었다. 관능평가 결과는 외관, 질감, 전체적인 수용도 면에서 대조구와 비교하였을 때, 보관 6일까지 유의적인 차이가 없었다. 따라서 저온 플라즈마와 UV-C 병행처리는 양상추에 존재하는 균을 저감하기 위한 효과적인 기술로 활용될 수 있을 것으로 생각되었다.

• 한국의류학회지
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• 제29권5호
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• pp.617-625
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• 2005

The purpose of this study was to develop functional and environment-friendly polyester fabric by irradiating Ultra-Violet, which was produced by the low-pressure mercury lamp. UV irradiation was conducted with various treatment times and distances. Also, pretreatments of solvents and photoinitiator were used to improve the surface modification effects. The effects of UV irradiation on the moisture regain were found to increase gradually with increase of UV treatment time and decrease of treatment distance. Compared the effects of UVC and UVA, UVC was more effective than UVA. Moisture regain and wicking of PET was increased after UV treatment in our experimental condition. And owing to increasing of moisture regain, static charge was decreased. Pretreatment of solvents such as methanol, ethyl ether and addition of photoinitiator such as Benzophenone accelerated surface modification. The moisture regain was increased but wicking was decreased with pretreatment and addition of photoinitiatior. Therefore it is considered as inappropriate f3r clothing because of wicking effects. Yellowness, tensile strength and elasticity slightly decreased after UV irradiation.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권10호
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• pp.479-488
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• 2001

The effects of accelerated Ultraviolet (UV) radiation on High temperature vulcanized (HTV), Room temperature vulcanized (RTV) silicone rubber and two types of ethylene propylene diene terpolymer (EPDM) used for composite insulator were inverstigated by hydrophobicity class (HC), surface voltage decay after corona charging, SEM-EDS, FTIR and XPS. The contact angle in two kinds of silicone rubber was scarcely change, but EPDM occurred to the loss of hydrophobicity followed by surface cracking and chalking. The surface voltage decay on UV-treated silicone rubber and EPDM showed a different decay trend with UV treatment. EDS and XPS analysis indicated that the oxygen content increased with UV treatment time in all samples. For silicone rubber, the oxidized groups of inorganic silica-like structure increased with UV treatment time. The oxidized carbon of C=0, O=C-O in EPDM increased. These oxidized surface for each material had different electrostatic characteristics, so deposited charges were expected to have different impacts on their surface hydrophobicity. The degradation mechanism based on our results was discussed.

• 상하수도학회지
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• 제21권6호
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• pp.663-670
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• 2007

This study was performed to provide basic information for evaluating the efficiency and applicable extent of photocatalysis and ozonation for the treatment of dye wastewater. The treatability of dye wastewater by $UV/TiO_2$ and $UV/TiO_2/O_3$ advanced oxidation process (AOP) was investigated under various conditions. The experiments were conducted in a batch reactor of 50 liters equipped with twelve UV Lamps of 16W. In $UV/TiO_2$ AOP, the removal efficiency of TCODMn and Color increased to 58% and 67% respectively with increasing UV intensity. Also, The removal efficiency of TCODMn and Color increased to 97% and 99% respectively with increasing $H_2O_2$. Acid area was more efficient than neutral and alkalic areas in wastewater treatment, and pH 5 was the most effective and the treatment efficiency continually increased as the amount of photocatalyst was increased. When the photocatalyst was increased, TCODMn was removed faster than Color.

• 한국식품영양학회지
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• 제36권1호
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• pp.17-24
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• 2023

To apply UV-C as a non-heating sterilization method to increase the microbiological safety of fresh seedless watermelon products, reductions in E. coli and quality changes by treatment dose (0, 2, 4, 8, 14, 20 kJ/m²) were investigated. The pH, sugar content, and hardness of watermelon inoculated with E. coli were not significantly different according to the UV-C treatment dose, but the polyphenol content was significantly decreased compared to the controls (425.4 GAE ㎍/g F.W.). When treated with 2 and 4 kJ/m², the lycopene content was 31.6 and 30.9 ㎍/g F.W., respectively, which was increased compared to the controls (28.5 ㎍/g F.W.). The arginine and citrulline content was also significantly increased compared to the controls. The number of E. coli was significantly decreased compared to the controls following UV-C treatment. Considering the degree of E. coli reduction, lycopene content, arginine content, citrulline content, and UV-C irradiation time, subsequent experiments were conducted by selecting a UV-C treatment dose of 2 kJ/m². The results of confirming the degree of reduction in the number of E. coli colonies by a single treatment and combined treatment with UV-C 2 kJ/m² and 70% ethanol showed that the combined treatment was most effective as colonies were decreased by 2.3 log CFU/g compared to the controls. Therefore, it is judged that UV-C 2 kJ/m² radiation and combined treatment with 70% ethanol could be applied as a non-heating sterilization method for fresh watermelon slices.

• 한국식품위생안전성학회지
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• 제33권6호
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• pp.495-499
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• 2018

후춧가루에 존재하는 식중독 균을 저감화시키기 위한 방법으로 UV-C와 mild heat를 병합 처리 가능성을 타진하였다. Escherichia coli O157:H7 (ATCC 35150)와 Salmonella Typhimurium (ATCC 19585)를 후춧가루에 각각 $10^6$, $10^7CFU/g$ 수준으로 인위접종하여 $2.32W/cm^2$의 UV-C와 $60^{\circ}C$의 mild heat을 10분에서 70분 동안 처리하였다. 그 후 미생물 분석 및 후춧가루의 품질변화를 측정하였다. UV-C를 단독으로 70분 동안 처리했을 때 E. coli O157:H7과 S. Typhimurium는 각각 1.89, 2.24 log CFU/g 수준으로 감소하였지만, UV-C와 mild heat을 70분 동안 병합처리 했을 때는 각각 2.46, 5.70 log CFU/g으로 감소하였다. E. coli O157:H7 보다는 S. Typhimurium의 저감효과가 더 컸다. 색도는 모든 처리구에서 유의적인 차이가 없는 것으로 나타났다. 따라서 UV-C와 mild heat 병합처리는 후춧가루에 존재하는 식중독 균을 사멸시키는 데 효과적이기 때문에 산업적인 살균처리 기술로 활용될 수 있을 것으로 판단되었다.