• 제목/요약/키워드: photodegradation

검색결과 224건 처리시간 0.035초

Efficient Photocatalytic Degradation of Salicylic Acid by Bactericidal ZnO

  • Karunakaran, Chockalingam;Naufal, Binu;Gomathisankar, Paramasivan
    • 대한화학회지
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    • 제56권1호
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    • pp.108-114
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    • 2012
  • Salicylic acid degrades at different rates under UV-A light on $TiO_2$, ZnO, CuO, $Fe_2O_3$, $Fe_3O_4$ and $ZrO_2$ nanocrystals and all the oxides exhibit sustainable photocatalysis. While ZnO-photocatalysis displays Langmuir-Hinshelwood kinetics the others follow first order on [salicylic acid]. The degradation on all the oxides enhance with illumination intensity. Dissolved oxygen is essential for the photodegradation. ZnO is the most efficient photocatalyst to degrade salicylic acid. Besides serving as the effective photocatalyst to degrade salicylic acid it also acts as a bactericide and inactivates E.coli even in absence of direct light.

Synthesis of CuO/ZnO Nanoparticles and Their Application for Photocatalytic Degradation of Lidocaine HCl by the Trial-and-error and Taguchi Methods

  • Giahi, M.;Badalpoor, N.;Habibi, S.;Taghavi, H.
    • Bulletin of the Korean Chemical Society
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    • 제34권7호
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    • pp.2176-2182
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    • 2013
  • A novel sol-gel method was implied to prepare CuO-doped ZnO nanoparticles. XRD and SEM techniques were used to characterize the CuO-doped ZnO sample. The photocatalytic degradation of Lidocaine HCl was investigated by two methods. The degradation was studied under different conditions such as the amount of photocatalyst, pH of the system, initial concentration, presence of electron acceptor, and presence of anions. The results showed that they strongly affected the photocatalytic degradation of Lidocaine HCl. The photodegradation efficiency of drug increased with the increase of the irradiation time. After 6 h irradiation with 400-W mercury lamp, about 93% removal of Lidocaine HCl was achieved. The degree of photodegradation obtained by Taguchi method compatible with the trial-and-error method showed reliable results.

TiO2/UV공정을 이용한 수중 MTBE의 광분해 특성 (Characteristic of Photodegradation of MTBE Using TiO2/UV Process)

  • 류성필;김성수;오윤근
    • 한국환경과학회지
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    • 제13권3호
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    • pp.289-295
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    • 2004
  • The objective of this study is to delineate removal efficiency of the MTBE in solution by $TiO_2$ photocatalytic degradation as a function of the following different experimental conditions: Initial concentration of MTBE, air flow rate in solution, $H_2O_2$ dosage and pH of the solution. Photodegradation rate was increased with decreasing initial concentration of MTBE. The removal efficiency was 82% after 180 min in the case of MTBE concentration of 100 mg/L but 100% after 180 min in the case of 20 mg/L. Removal efficiency was increased with increasing pH, $H_2O_2$ dosage and air flow rate in solution.

Pt (IV)/AMM-Ti 광촉매를 이용한 휴믹산에서의 1, 3, 5-Trichlorobenzene의 광분해반응의 연구 (Photodegradation Study of 1, 3, 5-Trichlorobenzene Using Pt (IV)/AMM-Ti Photocatalyst in Humic Acid (HA) Solution)

  • Kim, Jae-Hyoun
    • Environmental Analysis Health and Toxicology
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    • 제15권3호
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    • pp.93-98
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    • 2000
  • 1, 3, 5-TCB의 광분해를 목적으로 Pt (IV)/AMM-Ti 광촉매의 산화반응을 이용하여 조사시간, 농도, PH의 변수에 대한 효과 및 광분해물질의 성분분석과 휴믹산의 1, 3, 5-TCB의 분해에 미치는 영향을 연구하였다.

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푸로세미드의 안정성 및 생체내 이용율에 미치는 ${\beta}-$시클로덱스트린의 영향 (Influence of ${\beta}-Cyclodextrin$ on Stability and Bioavailability Of Furosemide)

  • 한건;유병권
    • Journal of Pharmaceutical Investigation
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    • 제18권3호
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    • pp.99-105
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    • 1988
  • Inclusion complex formation of furosemide with ${\beta}-cyclodextrin({\beta}-CyD)$ in solid state was confirmed by X-ray diffractometry, IR spectroscopy and differential scanning calorimetry (DSC). The solid complexes of ${\beta}-CyD$ with furosemide in molar ratio of 2 : 1 were prepared by solvent evaporation method. The photodegradation of furosemide in alkaline solution under the light and the hydrolysis of furosemide in acidic solution were not inhibited by complex formation with ${\beta}-CyD$. However, the bioavailability of furosemide was improved by complex formation with ${\beta}-CyD$ after oral administration to rats.

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자외선 처리시의 의약품류의 분해도에 관한 연구 (A Study on the Degradability of Pharmaceuticals during UV Treatment)

  • 김일호
    • 한국물환경학회지
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    • 제28권6호
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    • pp.902-910
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    • 2012
  • The photodegradation characteristics of 30 pharmaceuticals were investigated by batch experiments using Ultraviolet (UV) reactor. The investigated pharmaceuticals include antibiotics, analgesics and antiarrhythmic agents etc. Tested water was prepared by simultaneously spiking 30 pharmaceuticals into pure water, and each experiment was conducted using 3 types of UV lamps. As a result, batch experiments showed that reactions of all the investigated pharmaceuticals followed pseudo-first order reaction regardless of the applied UV lamps. Among the pharmaceuticals, Cyclophosphamide, 2-Quinoxaline carboxylic acid and Clarithromycin proved to be the most UV-resistant compounds. Contrarily, Ceftiofur, Diclofenac and Ketoprofen were easily degraded by all the UV lamps. Dissolved organic carbon (DOC) concentration hardly changed although the concentration of the pharmaceuticals concentration gradually decreased with time, indicating that the degradation of parent pharmaceuticals may produce their intermediates during UV treatment.

UV/Ozone 조사에 의한 PET 직물의 편면 발수가공 (One-side Water-repellent Finish of PET Fabrics using UV/Ozone)

  • 김수진;장진호
    • 한국염색가공학회지
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    • 제23권2호
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    • pp.100-106
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    • 2011
  • UV-curable water-repellent finish was carried out to impart one-side repellency to the PET fabrics using a formulation of a UV-active fluorocarbon agent and a water soluble photoinitiator. The aqueous formulation was padded on the PET fabrics and it was subsequently UV-cured. The unirradiated side of the cured fabrics was made to wetteable to water by the prolonged UV/ozone irradiation. The influence of photoinitiator concentration, agent concentration and UV energy for photodegradation on the performance of the finished fabrics were investigated. The difference in the functional property of front and back sides was examined by measuring water repellency at each side of the treated fabrics, which resulted in four rating difference between two-side. The UV-cured and photodegraded PET surfaces were characterized by ATR, ESCA and FE-SEM.

Preparation of $TiO_2$-Coated Polypropylene Beads by PCVD Process for Phenol Removal

  • Pham, Hung-Cuong;Kim, Dong-Joo;Kim, Kyo-Seon
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2009년도 추계학술대회 초록집
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    • pp.185-185
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    • 2009
  • Polypropylene beads (PP) coated with $TiO_2$ thin films were prepared by a rotating cylindrical plasma chemical vapor deposition (PCVD) reactor and were used to remove phenol in aqueous solution. The $TiO_2$ thin films of 416 nm thickness were coated on the PP particles uniformly. As the number of $TiO_2$-coated PP beads increases, the phenol is degraded faster, because of larger total surface area of photocatalysts for photodegradation. This study shows that a rotating cylindrical PCVD reactor can be a good method to prepare the particles coated with high-quality $TiO_2$ thin films, which can be applied to the pollutant removal by a photodegradation reaction of $TiO_2$ with high efficiency.

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