• Title/Summary/Keyword: Photo-Degradation

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Degradation of 2-Chlorophenol in the Aqueous Phase by a Photo-Fenton Process (광펜톤 반응에 의한 수중 2-클로로페놀 분해특성연구)

  • Kim, Il-Kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.6
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    • pp.779-786
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    • 2012
  • The degradation of 2-chlorophenol(2-CP) by various AOPs(Advanced Oxidation Processes) including the photo-Fenton process has been examined. In sole $Fe^{2+}$, UV or $H_2O_2$ process without combination, low removal efficiencies have been achieved. But the photo-Fenton process showed higher removal efficiency for degradation of 2-chlorophenol than those of other AOPs including the Fenton process and the UV processes. In the photo-Fenton process, the optimal experimental conditions of 2-chlorophenol degradation were obtained at pH 3 and the $Fe^{2+}/H_2O_2$molar ratio of 1. Also the 2-chlorophenol removal efficiency increased with decreasing of the initial 2-chlorophenol concentration. 3-chlorocatechol and chlorohydroquinone were identified as photo-Fenton reaction intermediates, and a degradation pathway of 2-chlorophenol in the aqueous phase during the photo-Fenton reaction was proposed.

Degradation of 4-Chlorophenol by a Photo-Fenton Process with Continuous Feeding of Hydrogen Peroxide (과산화수소 연속주입식 광펜톤산화공정에 의한 4-염화페놀 분해연구)

  • Kim, Il-Kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.27 no.1
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    • pp.31-38
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    • 2013
  • The degradation of 4-chlorophenol(4-CP) by various AOPs(Advanced Oxidation Processes) with continuous feeding of $H_2O_2$, including the ultraviolet/hydrogen peroxide, the Fenton and the photo-Fenton process has been investigated. The photo-Fenton process showed the highest removal efficiency for degradation of 4-chlorophenol than those of other AOPs including the Fenton process and the combined UV process with continuous feeding of $H_2O_2$. In the photo-Fenton process, the optimal experimental condition for 4-CP degradation was obtained at pH 3. Also the 4-CP removal efficiency increased with decreasing of the initial 4-CP concentration. 4-chlorocatechol and 4-chlororesorcinol were identified as photo-Fenton reaction intermediates, and the degradation pathways of 4-CP in the aqueous phase during the photo-Fenton reaction were proposed.

Degradation Of 4-chlorophenol By Photo-Fenton Process and Fenton Process in Aqueous Solutions (광펜톤반응과 펜톤반응에 의한 수중 클로로페놀 분해비교연구)

  • Kim, Hyun-Seung;Kim, Il-Kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.4
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    • pp.463-469
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    • 2011
  • The degradation of 4-chlorophenol by various AOPs(Advanced Oxidation Processes) including the Fenton and the photo-Fenton process has been examined. In sole Fe, UV or $H_2O_2$ process without combination, low removal efficiencies have been achieved. But the photo-Fenton process showed higher removal efficiency for degradation of 4-chlorophenol than those of other AOPs including the Fenton process. Generally more hydrogen peroxide was required to achieve higher removal efficiencies of 4-CP at constant dosage of $FeSO_4$ in both of the Fenton and the photo-Fenton processes. Based on the results, The photo-Fenton process is proposed to be the most efficient alternative for degradation of 4-chlorophenol among the processes studied in this research.

Degradation of 2,3-dichlorophenol by a Photo-Fenton Process with Continuous Pump-Feeding of Hydrogen Peroxide (동력펌프주입식 광펜톤시스템에 의한 2,3-디염화페놀 분해특성 연구)

  • Kim, Il-Kyu
    • Journal of Power System Engineering
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    • v.18 no.6
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    • pp.84-90
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    • 2014
  • The degradation of 2,3-dichlorophenol(2,3-diCP) by various advanced oxidation systems with continuous feeding of hydrogen peroxide including the ultraviolet/hydrogen peroxide, the Fenton and the photo-Fenton process has been conducted. The highest removal efficiency for 2,3-diCP in the aqueous phase was obtained by the photo-Fenton process among the advanced oxidation systems. In the photo-Fenton process, The removal efficiency of 2,3-diCP decreased with increasing pH in the range of 3 to 6, and it decreased with increasing initial concentration. As the intermediates of 2,3-diCP by photo-fenton reaction, 3,4-chlorocatechol and 2,3-dichlorohydroquinone were detected, thus the degradation pathways were proposed.

Accelerated Life Test of Knife Protection Fabrics for Cut Resistance (절단 방지용 방검소재의 가속수명시험)

  • Chang, Gap-Shik;Jung, Ye-Lee;Jeon, Byong-Dae
    • Journal of Applied Reliability
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    • v.15 no.4
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    • pp.270-275
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    • 2015
  • Purpose : UHMWPE (Ultra-high-molecular-weight-polyethylene) is one of the most widely used material in knife protection clothes because of high strength, elasticity, and light weight. The purpose of this study is to develop the accelerated life test method and predict the lifetime for the knife protection fabric composed by UHMWPE. Methods : In this study, degradation characteristics of UHMWPE fibers and knife protection fabric for cut resistance were evaluated under the hydrolysis and photo-degradation conditions. It was found out that the degradation rate of retained tensile strength was more significant in the photo-degradation than hydrolysis. Therefore, the failure time was determined as the time that the retained tensile strength in photo-degradation is less than 50%. Considering an acceleration factor for irradiance and exposure time, the lifetime was predicted from the calculated failure time. Results : As a result of the accelerated life test, the $B_{10}$ lifetime of knife protection fabric composed by UHMWPE fibers is estimated as 2.8 years for a 90% statistical confidence level. Conclusion: Since the lifetime is predicted by the view-point of radiant exposure in this study, there is a possibility that the estimated lifetime may differ from the actual lifetime. However, it is considered as an useful methodology to estimate the long-term lifetime of knife protection fabrics.

Preparation of TiO2 Photocatalysts by Diffusion Flame Reactor and Its Application on Photo-degradation of Phenol and Toluene (확산화염 반응기를 이용한 TiO2 광촉매 제조 및 페놀 및 톨루엔 광분해 응용)

  • Choi, Sang-Keun;Kim, Kyo-Seon
    • Journal of Industrial Technology
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    • v.22 no.B
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    • pp.117-124
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    • 2002
  • We prepared the nano-sized $TiO_2$ particles by the diffusion flame reactor and investigated the effects of several process variables on the generation and transport properties of $TiO_2$ particle. As the length from the tip of diffusion flame reactor increases, the size of $TiO_2$ particle increases by the coagulation between particles. The structure of $TiO_2$ particles prepared is almost found to be anatase. It was found that the $TiO_2$ particle size depends more largely on the change of reactor temperature than on the change of inlet $TiCl_4$ concentration. By the photo-degradation experiment of phenol and toluene with the prepared $TiO_2$ particles, we found that the photo-degradation efficiencies of phenol and toluene change, depending on the process variables such as size of $TiO_2$ photocatlysts, concentration of phenol or toluene. Degradation efficiencies of phenol and toluene was above 90% in our experiments in 60 minutes.

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A Study on the degradation of Lindane in water by a Photo-Fenton process and a UV/$H_2O_2$ process (Photo-Fenton 공정과 UV/$H_2O_2$ 공정을 이용한 Lindane의 분해특성 비교 연구)

  • Lee, Ju-Hyun;Choi, Hye-Min;Kim, Il-Kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.24 no.1
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    • pp.109-117
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    • 2010
  • In the present study, the degradation characteristics of Lindane by Advanced Oxidation Processes(UV/$H_2O_2$, Photo-Fenton process) were studied. The degradation efficiency of Lindane in aqueous solution was investigated at various initial pH values, Fenton's reagent concentrations and initial concentrations of Lindane. GC-ECD was used to analyze lindane. Lindane has not been degraded without application of AOPs over two hours. But, approximately 5% of lindane was degraded with UV or $H_2O_2$ alone. Lindane with UV/$H_2O_2$ process showed approximately 7% higher removal efficiency than $H_2O_2$ process. In the UV/$H_2O_2$ process, the pH values did not affect the removal efficiency. The optimal mole ratio of $H_2O_2/Fe^{2+}$ for lindane degradation is about 1.0 in Photo-Fenton process. Also, the experimental results showed that lindane removal efficiency increased with the decrease of initial concentration of lindane. Under the same conditions, the order lindane of removal efficiency is as following : Photo-Fenton process > UV/$H_2O_2$ process > $H_2O_2$ process. In addition, intermediate products were identified by GC-MS techniques. Than PCCH(Pentachlorocyclohexene) was identified as a reaction intermediate of the Photo-Fenton process.

A Study for Degradation Mechanism of Plastic Materials (플라스틱 소재의 탈변색 열화 메커니즘 분석)

  • Youn, Hyung-Joon;Jung, Won-Wook;Byun, Doo-Jin;Choi, Gi-Dae
    • Journal of Applied Reliability
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    • v.7 no.4
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    • pp.173-181
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    • 2007
  • Out door exposure to daylight and weather climate conditions can cause adverse effect on the properties of automotive plastic materials. The effects of sunlight exposure, especially ultra violet (UV) radiation, can break down the chemical bonds in a polymeric material. This degradation process is called photo-degradation and ultimately leads to color changes, cracking, chalking, the loss of physical properties and deterioration of other properties. To explore the effect of sunlight exposure on the automotive materials, this study investigated photo-oxidation degree and surface property change of molding parts by analytical methods. For the further study, accelerated weathering test methods are proposed, which can correlate with out door weathering, to predict long term performance of automotive plastic materials.

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Improved Photo Degradation of Rhodamine B Dye using Iron Oxide/Carbon Nanocomposite by Photo-Fenton Reaction

  • Kim, Min-Il;Im, Ji-Sun;In, Se-Jin;Kim, Hyuk;Kim, Jong-Gyu;Lee, Young-Seak
    • Carbon letters
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    • v.9 no.3
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    • pp.195-199
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    • 2008
  • A nanocomposite consisting of $Fe_3O_4$ and MWCNT was produced via sol-gel technique using $FeCl_3$ along with MWCNT by calcination at $300^{\circ}C$. The degradation effect of rhodamine B dye has been investigated under UV illumination in a darkroom. The degradation reaction was studied by monitoring the discoloration of dye as a function of irradiation time using UV-visible spectrophotometeric technique. The $Fe_3O_4$-MWCNT samples have continuous degradation ability under the UV illumination with the first order kinetics and the dye removal was better than in the pristine $Fe_3O_4$. The resultant composite catalyst was found to be efficient for the photo-Fenton reaction of the dye.

Removal of Rhodamine Dye from Water Using Erbium Oxide Nanoparticles

  • Luaibi, Hasan M.;Al-Taweel, Saja S.;Gaaz, Tayser Sumer;Kadhum, Abdul Amir H.;Takriff, Mohd S.;Al-Amiery, Ahmed A.
    • Korean Journal of Materials Research
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    • v.29 no.12
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    • pp.747-752
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    • 2019
  • Environmental pollution remains a considerable health risk source all over the world; however, hazards are usually higher in developing countries. Iraq has long been suffering from the problem of pollution and how to treat pollution. Photocatalytic degradation has turned out to be most productive process for dye degradation. In this investigation, Rhodamine B (RhB), dye has been selected for degradation under visible light illumination. To address this issue, we fabricate erbium trioxide nanoparticles (Er2O3/NPs). Erbium trioxide nanoparticles are prepared and utilized for photo-catalytic degradation. The characterization of Er2O3/NPs is described and confirmed by utilizing of XRD (X-ray diffraction) and SEM (Scanning Electron Microscopy). The average size of Er2O3 nanoparticles is observed to be 16.00 nm. Er2O3/NPs is investigated for its ability of photo-catalytic degradation through certain selected parameters such as concentration and time. The methodological results show that the synthesized Er2O3/NPs is a good photo-catalytic for Rhodamine degradation.