• Title/Summary/Keyword: UV treatment

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A study on improvement of ozone process by Granular Activated Carbon (입상 활성탄을 이용한 오존공정의 개선에 관한 연구)

  • Lee, Yu-Mi;Rhee, Dong Seok
    • Journal of Industrial Technology
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    • v.28 no.A
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    • pp.23-26
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    • 2008
  • Ozone/GAC and ozone-GAC processes were introduced for treatment of humic acid, which is representative refractory organic compound. The treatment efficiencies of humic acid in each process were analyzed in pH variation, DOC removal, and $UV_{254}$ decrease. $UV_{254}$ decrease in all processes was comparatively high with efficiency over 92%. $UV_{254}$ decrease in ozone alone process was 85%. DOC removal in Ozone-GAC process was the highest with 75%. Removal by Ozone/GAC, Ozone alone processes were 71% and 33% respectively.

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Blocking the 1st Cleavage in Mud Loach, Misgurnus mizolepis

  • Yoon Kwon Nam;Gyeong Cheol Choi;Dong Soo Kim
    • Journal of Aquaculture
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    • v.12 no.3
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    • pp.167-173
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    • 1999
  • Blocking the 1st mitotic cleavage was performed in mud loach (Misgurmus mizolepis) using UV-irradiated cyprinid loach (M. anguillicaudatus) sperm and ternal shocks Optimum UV range for inactivation of cyprinid loach sperm and thermal shocks. Optimum UV range for inactivation of cyprinid loach sperm was between 3,150 to 4,050 ergs/m$m^2$. Heat shock treatment ($41^{\circ}C$ for 3mins) with various treatment initiation times ranged from 22 to 50 min post insemination resulted wide range of success for induced gynogenesis. Best result was obtained when haploid egges were shocked at 28 min after insemination (corresponding to metaphase division of the 1st cleavage); 26% of total eggs inseminated were viable diploid gynogens. The hatching success and early survival of the both meiotic and mitotic gynogenetic groups were significantly lower than those of control crosses (P<0.05). Maternal origin of induced gynogenetic mud loach was verified by multi-locus DNA fingerprinting.

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Enhancement of UV-induced nucleotide excision repair activity upon forskolin treatment is cell growth-dependent

  • Lee, Jeong-Min;Park, Jeong-Min;Kang, Tae-Hong
    • BMB Reports
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    • v.49 no.10
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    • pp.566-571
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    • 2016
  • Forskolin (FSK), an adenylyl cyclase activator, has recently been shown to enhance nucleotide excision repair (NER) upon UV exposure. However, our study revealed that this effect was detected in human skin epithelial ARPE19 cells only in growing cells, but not in non-cycling cells. When the cells were grown at low density (70% confluence), FSK was capable of stimulating cAMP responsive element binding (CREB) phosphorylation, a marker for FSK-stimulated PKA activation, and resulted in a significant increase of NER activity compared to control treatment. However, cells grown under 100% confluent conditions showed neither FSK-induced CREB phosphorylation nor the resulting NER enhancement. These findings indicate that cellular growth is critical for FSK-induced NER enhancement and suggest that cellular growth conditions should be considered as a variable while evaluating a reagent's pharmacotherapeutic efficacy.

Fabric dyeing with Laminaria japonica as a marine resources (해양자원을 활용한 직물염색-다시마-)

  • Kim, Sangyool;Jeon, Soonduk
    • The Research Journal of the Costume Culture
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    • v.22 no.6
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    • pp.890-898
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    • 2014
  • This study focuses on the effects of dyeing conditions and mordanting conditions, changes of colorfastness, antibacterial properties and UV protective of silk fabric dyed with Laminaria japonica extracts. A natural colorant was extracted from Laminaria japonica using distilled water as extractants. According to the results, maximum dye uptake (K/S) were obtained at 100% V/V colorant concentration, $80^{\circ}C$, 60 min and pH 2. Silk fabric was dyed with Laminaria japonica extract at $80^{\circ}C$ for 60 min with pre-treatment or post-treatment of various metal salts as mordants. The Laminaria japonica extracts produced yellow hue on silk fabric in pre-mordanting and manifested green yellow hue mordanted with $CuSO_4$ in post-mordanting method. Mordant $CuSO_4$ for silk fabric was found to give good light fastness (rating 4). UV protection property did not increase significantly upon mordanting.

The Study of VOCs Decomposition Characteristics Using UV Photolysis Process (휘발성유기화합물의 광분해 제거 특성에 관한 연구)

  • 서정민;정창훈
    • Journal of Environmental Science International
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    • v.11 no.7
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    • pp.743-748
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    • 2002
  • UV photolysis process is little known in parts of air pollution treatment, so there are not many applications in field. Therefore we have to do more experiment and study application possibility for treatment of VOCs(Volatile organic compounds). To solve these problems, we have been studying for simultaneous application of this technology. It has shown that concentration of TCE and B.T.X., diameter of reactor and wavelength of lamp have effected on decomposition efficiency. Analysis of TCE and B.T.X. concentration was carried out by GC-FID. A cylinderical reactor consisting of a quartz tube and a centrally located lamp(${\psi}25mm$) was used. The length and diameter of reactor were 1800mm, 75mm. It has shown that the generated ozone concentration goes up 250ppm when using 64watt ozone lamp. When using Photolysis process only, the rates of fractional conversion of each material are TCE 79%, Benzene 65%, Toluene 68%, Xylene 76%. This phenomenon can be rationalized in terms of the different bond energy that indicates how easily VOCs species can be decomposed.

Electrical Properties of a CuPc Field-Effect Transistor Using a UV/Ozone Treated and Untreated Substrate

  • Lee, Ho-Shik;Cheon, Min-Woo;Park, Yong-Pil
    • Transactions on Electrical and Electronic Materials
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    • v.12 no.1
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    • pp.40-42
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    • 2011
  • An organic field-effect transistor (OFET) was fabricated using a copper phthalocyanine (CuPc) as the active layer on the silicon substrate. The CuPc FET device was configured as a top-contact type. The substrate temperature was room temperature. The CuPc thickness was 40 nm, and the channel length and channel width were 100 ${\mu}m$ 3 mm, respectively. Typical current-voltage (I-V) characteristics of the CuPc FET were observed and subsequently compared to the UV/ozone treatment on substrate surface.

Disinfection of E. coli from Wastewater using a Non-contact type UV Photoreactor and Log Inactivation Index (비접촉식 자외선 광반응조를 이용한 하수 대장균의 살균과 Log 불활성화율 지표)

  • Kim, Sunghong;Kim, Kyungmyun;Kim, Gwangil;Choe, Jaewan
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.2
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    • pp.139-145
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    • 2016
  • Disinfection of microorganisms using UV light is widely used in the field of water supply and wastewater treatment plant, In spite of high germicidal effect and relatively clean by-product, UV disinfection has fundamental defeat that is accumulation of fouling materials at the interface of water and lamp sleeve. Non-contact type of UV photoreactor which can avoid this fouling generation was developed and the experimental performance evaluation of the system was carried out in this study. Log inactivation rate of E. coli was selected as a disinfection index. The concentration of E. coli of second clarifier effluent was $8.2{\times}10^1-8.2{\times}10^3$ colony per mL and was well inactivated by the non-contact type of UV photoreactor. Under the UV intensity condition of $2.1-2.5mW/cm^2$, E. coli removal rate was observed in the range of 54 - 95% when the HRT was increased from 10 to 52 seconds. Experimental results showed that log inactivation of E. coli was proportional to UV dosage and $200mJ/cm^2$ of UV dose is expected for the 2.0 log inactivation of E. coli from the second clarifier effluent. Between the two parameters of UV intensity and contact time which are consist of UV dose, UV intensity was 4 times more effective than contact time.

Development of Wastewater Treatment System by Energy-Saving Photocatalyst Using Combination of Solar Light, UV Lamp and $TiO_2$ (태양광/자외선/이산화티타늄($TiO_2$)을 이용한 에너지 절약형 광촉매 반응 처리시스템 개발)

  • 김현용;양원호
    • Journal of Environmental Health Sciences
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    • v.29 no.1
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    • pp.51-61
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    • 2003
  • Pollution purification using titanium dioxide (TiO$_2$) photocatalyst has attracted a great deal of attention with increasing number of relent environmental problems. Currently, the application of TiO$_2$ photocatalyst has been focused on purification and treatment of waste water. However. the use of conventional TiO$_2$ powder photocatalyst results in disadvantage of stirring during the reaction and of separation after the reaction. And the usage of artificial UV lamp has made the cost of photocatalyst treatment system high. Consequently, we herein studied the pilot-scale design to aid in optimization of the energy-saving process for more through development and reactor design by solar light/UV lamp/ TiO$_2$system. In this study, we manufactured the TiO$_2$sol by sol-gel method. According to analysis by XRD, SEM and TEM, characterization of TiO$_2$ sol were nano-size (5-6 nm) and anatase type. Inorganic binder (SiO$_2$) was added to TiO$_2$ lot to be coated for support strongly, and support of ceramic bead was used to lower separation rate that of glass bead The influences were studied of various experimental parameters such as TiO$_2$ quantity, pH, flow rate. additives, pollutants concentration, climate condition and reflection plate by means of reaction time of the main chararteristics of the obtained materials. In water treatment system, variable realtor as solar light/ or UV lamp according to climate condition such as sunny and cloudy days treated the phenol and E-coli(Escherichia coli) effectively.

Hybrid Water Treatment of Tubular Ceramic MF and Photocatalyst Loaded Polyethersulfone Beads : Effect of Organic Matters, Adsorption and Photo-oxidation at Nitrogen Back-flushing (관형 세라믹 정밀여과와 광촉매 첨가 PES 구의 혼성 수처리 : 질소 역세척 시 유기물 및 흡착, 광산화의 영향)

  • Hong, Sung Taek;Park, Jin Yong
    • Membrane Journal
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    • v.23 no.1
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    • pp.61-69
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    • 2013
  • The effect of humic acid (HA), and the roles of microfiltration (MF), PES (polyethersulfone) beads adsorption, and photo-oxidation were investigated in hybrid process of ceramic MF and PES beads loaded with titanium dioxide ($TiO_2$) photocatalyst for advanced drinking water treatment. Those were compared and studied in viewpoints of membrane fouling resistance ($R_f$), permeate flux (J), and total permeate volume ($V_T$). Because membrane fouling increased dramatically as decreasing HA, $R_f$ increased and J decreased, and finally $V_T$ was the highest at 2 mg/L HA. In the experiment to investigate the roles of photo-oxidation and adsorption at humic acid 4 mg/L and 6 mg/L. In both conditions, $R_f$ was the lowest and $V_T$ was the highest in MF + $TiO_2$ + UV process. The average treatment efficiencies of turbidity and dissolved organic matters were the highest in MF + $TiO_2$ + UV process, too.

Application of a Microbial Toxicity Assay for Monitoring Treatment Efficiency of Pentachlorophenol in Water using UV Photolysis and $TiO_2$ Photocatalysis

  • Kim, Jung-Kon;Cho, Il-Hyung;Zoh, Kyung-Duk;Choi, Kyung-Ho
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2004.06a
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    • pp.146-150
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    • 2004
  • Degradation efficiency of pentachlorophenol (PCP) by using direct UV photolysis and $TiO_2$ photocatalysis was evaluated with both chemical analyses and acute toxicity assessment employing luminescent bacteria Vibrio fischeri. PCP was chosen as a target compound in this study because of its wide application as fungicide, bactericide, insecticide and wood preservative in agriculture and many industries, in addition to its well-known environmental consequences. The acute toxicity to the microbe was reduced by >60% when applying UV alone, and was completely removed when treated with $UV-TiO_2$ combinations. Toxicity reduction pattern determined with the Microtox Assay generally corresponds with the chemistry data: However, it should be noted that toxicity was greater than expected by the chemistry data. Formation of TCBQ, a toxic byprodut, could not explain observed microbial toxicity. These observations are probably due to the presence of unidentified toxic PCP byproducts, which may include polychlorinated dibenzodioxins and polychlorinated dibenzofurans. When Microtox results were compared between different exposure time, i.e.,5 min and 15 min, an interesting pattern was noted with $UVA-\;TiO_2$ treatment. While no microbial toxicity was observed with 5 min exposure, an EC50 value of 45.4% was estimated with 15 min exposure, which was not observed in $UVB-\;TiO_2$ exposure. This result may suggest the presence of unidentified toxic degradation products generated in the later stage of treatment. Based on this study, $TiO_2$ photocatalyst, together with UVB photolysis could improve the removal of both PCP and its toxic derivatives in more efficient way. The Microtox Assay is promising and economical method for monitoring efficiency of wastewater treatment processes.

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