• 제목/요약/키워드: chemically oxidized intermediate

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PAHs 오영 토양의 Fenton 보조 동시산화 (Fenton Reaction Assisted Cooxidation for PAHs Contaminated Soils)

  • 류선정;박갑성
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 1998년도 총회 및 춘계 학술발표회 논문집
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    • pp.53-60
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    • 1998
  • The effect of chemically oxidized intermediated of PAH compounds on the degradation of the parent PAHs was characterized and evaluated for the context of cooxidation. Anthracene and pyrene exhibited extensive degradation (mean percent removal of 57.5%) after 28 days of incubation by introducing the Fenton oxidation intermediate of the PAH compounds, while unoxidized anthracene and pyrene exhibited 12.5% removal. Dehydrogenase activities for the oxidized PAH studies ware enhanced two to five folds to the unoxidized PAHs studies. The chemical oxidation products can serve as a structually very similar analogue substrates for a consortia of soil microorganisms and as a metabolic intermediates in the biodegradation sequence of the parent PAH compounds. These results may be interpreted in the context of cooxidation mechanism whereby high recalcitrant PAH compounds are biodegraded in the soil and suggest a potential tool for bioremediation of PAHs contaminated soils and protection of groundwater.

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난분해 PAHs의 화학적산화에 의한 유사기질동시대사 (Analogue Substrate Cometabolism by Chemical Oxidation of Recalcitrant PAHs)

  • 류선정;박갑성
    • 한국토양환경학회지
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    • 제3권3호
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    • pp.87-92
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    • 1998
  • The effect of chemically oxidized intermediates of Polynuclear Aromatic Hydrocarbon (PAH) compounds on the degradation of the parent PAHs was characterized and evaluated for the context of cooxidation. Anthracene and pyrene exhibited extensive degradation (mean percent removal of 57.5%) after 28 days of incubation by introducing the Fenton oxidation intermediate of the PAH compounds, while unoxidized anthracene and pyrene exhibited 12.5% removal The chemical oxidation products can serve as a structually similar analogue substrates for a consortia of soil microorganisms and as a metabolic intermediates in the biodegradation sequence of the parent PAH compounds. These results may be interpreted in the context of cooxidation mechanism whereby high recalcitrant PAH compounds are biodegraded in the soil and suggest a potential tool for bioremediation of PAHs contaminated soils and protection of groundwater.

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Photoemission Study on the Adsorption of Ethanol on Chemically Modified TiO2(001) Surfaces

  • Kong, Ja-Hyun;Kim, Yu-Kwon
    • Bulletin of the Korean Chemical Society
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    • 제32권8호
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    • pp.2531-2536
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    • 2011
  • Ethanol is a prototype molecule used in probing catalytic reactivity of oxide catalysts such as $TiO_2$. In the present study, we adsorbed ethanol on $TiO_2$(001) at room temperature (RT) and the corresponding bonding state of ethanol was systematically studied by x-ray photoemission spectroscopy (XPS) using synchrotron radiation. Especially, we compared $TiO_2$(001) surfaces prepared in ultra-high vacuum (UHV) with different surface treatments such as $Ar^+$-sputtering and oxidation with molecular $O_2$, respectively. We find that the saturation coverage of ethanol at RT varies depending on the amount of reduced surface defects (e.g., $Ti^{3+}$) which are introduced by $Ar^+$-sputtering. We also find that the oxidized $TiO_2$(001) surface has other type of surface defects (not related to Ti 3d state) which can dissociate ethanol for further reaction above 600 K. Our C 1s core level spectra indicate clearly resolved features for the two chemically distinct carbon atoms from ethanol adsorbed on $TiO_2$(001), showing the adsorption of ethanol proceeds without C-C bond dissociation. No other C 1s feature for a possible oxidized intermediate was observed up to the substrate temperature of 650 K.