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        검색결과 434

        421.
        2004.01 KCI 등재 서비스 종료(열람 제한)
        In this study, the decomposition of gas-phase TCE, Benzene and Toluene, in air streams by direct UV Photolysis and UV/TiO2 process was studied. For direct UV Photolysis, by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene and Benzene in this work were determined to be 0.00392s-1, 0.00230s-1 and 0.00126s-1, respectively. And the adsorption constant K of TCE, Toluene and Benzene in this work were determined to be 0.0519mol-1 ,0.0313mol-1 and 0.0084mol-1, respectively. For UV/TiO2 system by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene, and Benzene in this work were determined to be 5.74g/ℓ․min, 3.85g/ℓ․min, and 1.18g/ℓ․min, respectively. And the catalyst adsorption constant K of TCE, Toluene, and Benzene in this work were determined to be 0.0005m3/mg, 0.0043m3/mg and 0.0048m3/mg, respectively.
        422.
        2003.10 KCI 등재 서비스 종료(열람 제한)
        The aim of this study is, firstly, to find out what kinds of inorganic species are produced in the photocatalytic oxidation of ammonium-nitrogen containing water and, secondly, to seek the influence of anion for the photocatalytic oxidation of ammonium contained compounds. The photoenergy above 3 eV(λ<415 nm) was effectively absorbed by TiO2 and TiO2/polymer was used to be oxidized NH4-N in wastewater to NO3-N. Existing the anion as Cl-, the rate of photocatalytic oxidation decreased regardless of other condition. This result showed that the chloride ions reduced the rate of oxidation by scavenging oxidizing radical species as OH- and OCl-. Some of the added ion might have blocked the active sites of the catalyst surface, thus deactivated the catalyst.
        424.
        2002.03 KCI 등재 서비스 종료(열람 제한)
        One of the Musty and earthy smell compounds in raw water is generally attributed to 2-methylisoborneol (2-MIB). It is well known that activated carbon and oxidants such as O3, ClO2 are effective ways to control 2-MIB. In isotherm equilibrium experiments, 2-MIB in distilled water was much more adsorbed to the activated carbon(A/C) than raw water containing dissolved organic carbon (DOC). The Freundlich constants(k) of distilled water and raw water were 3.36 and 0.049, and 1/n values were 0.80 and 0.42, respectively. The 2-MIB residual rate were Y = e-0.55x~ e-0.54x with Ozone(O3) dose by 5 minutes contact time at the 241 and 353 ng/L initial concentrations. The 2-MIB residual rate were Y = e-0.32x~ e-0.35x with Chlorine dioxide(ClO2) dose by 15 minutes contact time at the 89 and 249 ng/L initial concentrations. 2-MIB was decreased from 1911 ng/L to 569ng/L by post-ozonation(70%removal efficiency) and removal efficiencies of 2-MIB by the following 4 kinds Granular Activated Carbon(GAC) process such as coal base, coconut base, wood base and zeolite+carbon base were 95.8, 89.5, 88.4, and 93.7% respectively.
        426.
        2001.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        가열우지중 콜레스테롤 산화안정성을 연구하기 위하여 130, 150 및 18 가열온도에서 일정시간 가열하였을 때 생성되는 각종 콜레스테롤 산화생성물을 TLC에 의하여 분리.확인하고, 지방산 조성의 변화를 측정하였다. 지방산 조성은 가열시간이 경과함에 따라 linoleic과 linolenic acid등의 불포화 지방산은 약간씩 감소한 반면 포화지방산의 함량은 다소 증가하는 경향이었고, 이러한 변화는 가열온도가 높을수록 심하였다. 추출한 비비누화물의
        428.
        1999.12 KCI 등재 서비스 종료(열람 제한)
        The advanced oxidation process (AOP) using ozone combined with hydrogen peroxide and ultraviolet treatment were evaluated for biodegradable dissolved organic carbon (BDOC) formation and dissolved organic carbon (DOC) removal. Oxidation treatment were conducted alone or combination with ozone, hydrogen peroxide and ultraviolet processes. Ozone dosage of ozone process was varied from 0.5㎎/ℓ·min to 5㎎/ℓ·min. Ozone/hydrogen peroxide process was done using 20㎎/ℓ of hydrogen peroxide concentration. Ozone/ultraviolet process was irradiated with 12mW/㎠ of density and 254nm. Ozone dosage was varied from 0.5㎎/ℓ·min to 5㎎/ℓ·min at the ozone/hydrogen peroxide and ozone/ultraviolet processes too. Contact time of all the process was 20 minutes. Oxidation treatment were performed on microfiltration effluent samples. BDOC formation was reached to an optimum at ozone dosage of 1.5㎎/ℓ·min in the ozone/hydrogen peroxide process and 1㎎/ℓ·min in ozone/ultraviolet process, after which BDOC formation was decreased at higher ozone dosages. But BDOC formation was increased with ozone dosages increasing in ozone process. The efficiency of DOC removal was higher AOPs than ozone process. Ozone/ultraviolet proces was the highest for DOC removal efficiency in each process. THMFP removal efficiency by ozone/ultraviolet process was higher than that by each of ozone process and ozone/hydrogen peroxide process.
        430.
        1999.03 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study was carried out to investigate the effect of Pine needle extract on lipid oxidation and free radical reaction in iron sources reacted with active oxygen species. The results were summarized as follow; The pine needle extracts didn`t show a distinct effect on reduction of lipid oxidation if the iron ion didn`t exist in oil emulsion. The pine needle extracts played role as a strong chelating agents to bind iron ion if Ferrous iron(Fe\ulcorner) exist in oil emulsion. Ferric iron(Fe) was lower effect than Ferrous iron(Fe) on free radical reaction in oil emulsion. And also, the Fe\ulcorner reacted with pine needle extract did not show distinct effect on free radical reaction, compared to Fe\ulcorner reacted with pine needle extract. And also, Pine needle extracts reacted with H\ulcornerO\ulcorner were tended to show a low oxygen scavenging ability in case of H\ulcornerO\ulcorner only was existed, compared to those of H\ulcornerO\ulcorner + Fe\ulcorner complex. Pine needle extracts were the most powerful Fe\ulcorner binding agents, compared to other strong synthetic antioxidants such as EDTA and DTPA.
        431.
        1997.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Proximate compositions of black rice and antioxidative effects of its methanol extract on refined perilla oil were investigated. Black rice seeds were composed of water 12.4%, crude protein 7.9%, crude fat 2.2%, crude fiber 1.0%, ash 1.4% and N-free extract 75.1%. The hexane and 80% methanol fractions in yields were higher than 80% ethanol and chloroform. In AOM(active oxygen method) test, antioxidative effects of black rice added to the refined perilla oil was increased with dose-dependent fashion in concentration of the black rice extracts. Among several extracts tested, 80% aqueous methanol extract showed the highest antioxidative activity, followed by hexane, chloroform, in that order. The peroxide value and TBA value for their antioxidation stability were also lower than that of control. This result was similar to that of AOM test.
        432.
        1996.02 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to evaluate the partial oxidation of the biological treatment plant effluents using Fenton`s reagent as a pretreatment step prior to a tertiary biological oxidation of these effluents. Fenton`s reagent was evaluated as a pretreatment process for inhibitory or refractory organics. Based on the Fenton oxidation system, the petrochemical wastewater treatment plant effluent was shown to have significant improvement in toxicity after oxidation with hydrogen peroxide. For example, at range of 42∼184 ㎎/L COD of petrochemical plant effluents, the COD removal efficiencies were from 38.2% to 60.1% after reaction with hydrogen peroxide 200 ㎎/L and Fe^2+ 100 ㎎/L and reaction time was 30 minutes. The total TOC reduction were about 15.8∼22.4% with same test condition and difference between the overall removal rate and BOD/COD ratio after Fenton`s oxidation estabilished in the biodegradation and otherwise meets the discharge standard or reuse for cooling tower make-up water.
        433.
        1995.12 KCI 등재 서비스 종료(열람 제한)
        Reuse of industrial effluents through the cooling systems in a petrochemical complex was described. The partial oxidation of the effluents from the biological treatment plant was examined, using Fenton`s reagent as a pretreatment step prior to a next treatment of the effluents. Next tertiary treatment using fixed-film reactor resulted in marked reductions in COD and suspended solids. The continuous fixed-film process with Fenton oxidation pretreatment showed a 23% increase in the COD removal efficiency when compared to that without pretreatment of Fenton oxidation under the volumetric organic loading rate of 0.1 ㎏ COD/㎥/day. The Fenton oxidation treatment seemed to be a possible method for tertiary biological treatment to reduce the residual toxicity with the enhanced biodegradation of the effluents.
        434.
        1992.12 KCI 등재 서비스 종료(열람 제한)
        The present study was performed to develop the removal system of the offensive gases, including hydrogen sulfide of acid gas, ammonia or amine of base gas, from the nightsoil treatment plant. In order to remove the offensive gases, the Fe-EDTA system liquid phase catalytic oxidation method with the bubble lift column reactor was employed. From the results obtained it was confirmed that the offensive gases can be deodorized simultaneously and also hydrogen sulfide of acid gas, ammonia of base gas completely removed at pH 6.45. In addition, as input gases feed rate the efficiency of acid gas did not change but the efficiency of base gases decreased to approximately 90% at pH 6.0. From the result of particle size analyzer, it was found that the particle sizes including sulfur and other impurites grew up to 21μm over 72hour reaction time.
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