• 한국환경과학회지
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• 제11권7호
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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.

• 한국염색가공학회지
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• 제8권1호
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• pp.43-55
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• 1996

When some disperse dye was decolored with oxidation power of ozone, the results in investigation of decoloration behavior with dye solution and its order of reaction and variation of TOC were as follow: 1. Order of decoloration for Some disperse dye is C.I. Disperse Blue 79>Blue 73> Red 343>Red 60>Blue 354>Yellow 42. 2. Velocity of decoloration for the all dyestuffs was the fastest when pH 3. 3. TOC was rapidly reduced between 10 min. and 20 min. 4. For the reduction of TOC ozone was needs many times as compared with decoloration of dyestuffs.

• 한국작물학회지
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• 제51권2호
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• pp.142-147
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• 2006

The present study describes carbohydrate metabolism, macro-element utilization and antioxidant defenses in response to an ozone dose (100 ppb, 8d) in two rice varieties. Tolerant (cv. Jinpumbyeo) and sensitive (cv. Chucheongbyeo) varieties of rice were grown in growth chamber for 30 days after sowing. Concentrations of chloroplast pigments and non-structural carbohydrates as well as activity of antioxidant enzymes were determined to evaluate the resistance against ozone stress. Ozone caused the decrease in chlorophyll a and carotenoid contents, and also resulted in faster decomposition of non-structural carbohydrate in leaf blade and leaf sheath. The contents of nitrogen and potassium in leaves were visibly decreased in cv. Chucheongbyeo with an increase in ozone exposure, but not in cv. Jinpumbyeo. Enzymatic antioxidants against ROS in both varieties responded in the order of POD, SOD and CAT, and their capacity was stronger in cv. Jinpumbyeo.

• Korean Chemical Engineering Research
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• 제51권4호
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• pp.523-526
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• 2013

본 연구에서는 수질정화 기술개발을 위하여 수산화라디칼 및 오존 발생기를 이용하여 수중에 존재하는 천연 지방산 분해 제거 연구를 수행하였다. 천연 지방산은 수산화라디칼 및 오존에 의하여 1차 분해반응 형태로 제거되었으며, 천연 지방산의 분해반응에서 수산화라디칼 단독으로 사용하는 것 보다 오존과 함께 사용한 경우 분해 효율을 크게 향상시킬 수 있음을 알 수 있었다. 또한, 천연 지방산이 수산화라디칼과 오존에 의해 분해되는 화학반응 기구를 제안하였다.

• 상하수도학회지
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• 제29권4호
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• pp.481-491
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• 2015

The aim of this study was to evaluate the chemical quenching system for residual ozone and to determine the operating condition for the quenching system. Hydrogen peroxide ($H_2O_2$) and sodium thiosulfate ($Na_2S_2O_3$) were investigated as quenching reagents for ozone removal, and the tendency of each chemical was notably different. In the case of $H_2O_2$, the degradation rate of ozone was increased as the concentration of $H_2O_2$ increase, and temperature and pH value have a significant effect on the degradation rate of ozone. On the other hand, the degradation rate of ozone was not affected by the concentration of $Na_2S_2O_3$, temperature and pH value, due to the high reactivity between the ${S_2O_3}^{2-}$ and ozone. This study evaluates the decomposition mechanism of ozone by $H_2O_2$ and $Na_2S_2O_3$ with consideration for the water quality and reaction time. Furthermore, the removal test for the quenching reagents, which can be remained after reaction with ozone, was conducted by GAC process.

• 한국환경보건학회지
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• 제22권1호
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• pp.57-64
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• 1996

The main objectives of this research program were to study the ozonation characteristics of phenol wastewater in the continuous packed colamn reactor(PCR) and the bubble column reactor (BCR) using ozone and to provide the fundamentals of ozonizing the phenol wastewater. Among various influencing factors that affect on phenol decomposition through the oxidation by ozone, contacting method, and ozone flow rate were chosen as reaction parameters. The results were obtained from two different types of contacting methods where the countercurrent flow was more efficient than the cocurrent flow in both the phenol removal efficiency and the ozone utilization efficiency. Furthermore, PCR showed the phenol removal efficiency 1.6 to 3% higher than that of BCR in both contacting methods, as well as the ozone utilization efficiency, suggesting that the countercurrent flow is more efficient than the cocurrent flow. The phenol removal efficiency and the ozone utilization efficiency were reduced in both reactors as the influent ozone flow rate increased. Upon varing flow rate from 0.5l/min to 2.0 l/min by 0.5 l/min, the phenol removal efficiency was reduced approximately from 8.5% to 10.5% and the ozone utilization efficiency was reduced approximately from 6% to 8% in both reactors. The performance of PCR was superior to that of BCR in the aspects of phenol removal and ozone utilization efficiency.

• Journal of Forest and Environmental Science
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• 제34권2호
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• pp.153-161
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• 2018

Ozone absorbs ultraviolet light which is harmful to life. However, the recent increase of ambient ozone level due to climate change is becoming the cause of stimulating human eyes, affecting respiratory system, and damaging crops. In this paper, a study was conducted at the Taehwa Research Forest (TRF) of Seoul National University with the purpose of analyzing the characteristics of forest air chemistry based on the measurement of BVOCs emitted from forests and investigating the correlation of BVOCs with ozone generation. The results showed that levels of isoprene and MVK (Methyl Vinyl Keton)+MACR (Methacrolein) were high in summer, but level of monoterpene was high in spring. Ozone level was high from the middle of May to the middle of June, which was before the rainy season. Comparison of the correlation between ozone and isoprene during the measurement period at the TRF showing limited NOx showed that the $R^2$ was correlated with a low value of about 0.4. However, when the isoprene was actively produced from 6:00 AM to 6:00 PM, correlation analysis showed that $R^2$ was about 0.9, while monoterpene started to increase in the afternoon, and decreased level of ozone at night. Correlation analysis showed negative correlation. Forests have two characteristics: not only the formation of ozone but also the decomposition of ozone.

• Journal of Korean Society for Atmospheric Environment
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• 제21권E2호
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• pp.57-65
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• 2005

An experimental study was performed on the decomposition of gaseous ammonia and two selected volatile organic compounds (VOCs: toluene and acetone) in a combined nonthermal plasma reactor with corona and glow discharges. A lab pilot scale reactor (206 liter) equipped with a high electric power pack was used to determine the decomposition efficiency in relation with the inlet concentration and applied voltage. Three different types of discharging electrode such as wired rack, wire strings for corona discharge, and thin plate for glow discharge were put in order in the reactor. While decomposition of ammonia decreased with an increase in the initial concentration, acetone showed an opposite result. In the case of toluene however no explicit tendency was found in toluene and aceton. Negative discharge resulted in high decomposition efficiency than the positive one for all gases. A better removal of gas phase element could be achieved when fume dust were present simultaneously.

• 공업화학
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• 제29권4호
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• pp.432-439
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• 2018

활성탄의 화학적 흡착 및 오존촉매반응의 작용기를 향상시키기 위해 Fe, Co, Mn 및 Pd 금속들을 활성탄에 담지하여 금속촉매 활성탄을 제조하였다. 고급산화공정의 실험결과에서 페놀 분해속도, 용존 오존 분해율 및 TOC (총유기탄소) 제거율은 Pd-AC > Mn-AC > Co-AC > AC > Fe-AC의 순서로 나타났다. BET 분석에서 금속담지활성탄의 물리적 특성은 오존촉매반응에 영향을 미치지 않았으며, 촉매효과는 담지한 금속의 종류에 따라 상이한 결과를 나타내었다. RCT (생성된 OH radical과 오존의 비율) 값 측정은 OH radical과 쉽게 반응하지만 오존과는 매우 느리게 반응하는 probe compound로 알려진 파라-클로로벤조산(p-chlorobenzoic acid)의 분해결과로부터 구할 수 있었으며, 오존단독 공정은 $5.48{\times}10^{-9}$, 활성탄 공정은 $1.47{\times}10^{-8}$로 측정되었고, Fe-AC, Co-AC, Mn-AC 및 Pd-AC 공정은 각각 $2.13{\times}10^{-9}$, $1.51{\times}10^{-8}$, $4.77{\times}10^{-8}$ 및 $5.58{\times}10^{-8}$로 측정되었다.

• 분석과학
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• 제13권5호
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• pp.652-658
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• 2000

오존 분자와의 직접반응경로 및 OH라디칼을 통한 간접반응경로를 통한 부식산의 분해특성을 TOC, $UV_{254}$ 그리고 오존 소모량의 변화를 통해 살펴보았다. 부식산의 분해를 위한 반응시스템은 오존 단독 처리 외에 OH라디칼의 생성조건을 조사하기위해 pH를 5에서 염기성 영역인 9까지 변화시켰으며, OH라디칼 생성 촉진제인 $H_2O_2$를 5-15 mg/L의 농도로, 그리고 OH라디칼 소거제로서 작용하는 $HCO_3{^-}$는 20-100 mg/L로 변화시키면서 처리하였다. 각 반응 조건에 따른 부식만의 분해특성을 살펴본 결과, TOC 제거율은 주로 0H라디칼에 의한 간접반응의 영향을 받았으며, $UV_{254}$ 감소율은 주로 오존분자와의 직접반응에 의해 효율이 결정되는 반응 경로를 거치는 것으로 나타났다. 또한 오존소모량은 주로 용액의 pH, alkalinity 변화에 따른 영향을 많이 받았다.