• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.237-238
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• 2002

과산화수소는 광화학적 이차 생성물질이며 대기의 산화상태를 알려주는 지시자의 역할을 한다. H2O2 는 O3의 광분해로 시작되는 광화학 반응 중 HO2 radical 의 self reaction(HO2＋ HO2＋M$\longrightarrow$H2O2＋M)으로 주로 생성된다(Lee,2000). 대기 내 수명이 1-2일인 과산화수소를 측정하므로써 오존의 대표적인 전구물질인 NOx와 VOC를 산화시키는 OH, HO2 라디칼의 농도를 예측할 수 있고 궁극적으로 오존을 저감하는 대책을 세우는데 필요한 요인으로 사용된다. (중략)

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.703-709
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• 2013

Ozonation was performed under various experimental conditions that $Al_2O_3$ catalysts dosage and temperature for removal of DMP in laboratory scale batch reactor. Flow rate of ozone $1.0Lmin^{-1}$ and ozone concentration of $300{\pm}10mgL^{-1}$ were maintained constantly, and the pH, $COD_{Cr}$ and TOC was measured in 10 min intervals during the 60 min at oxidation processes. As a result, the presence of the $Al_2O_3$ than only ozonation increased the removal efficiency of both $COD_{Cr}$ and TOC in solution. The pseudo first-order rate constants for the elimination of $COD_{Cr}$ and TOC were $3.65{\times}10^{-4}sec^{-1}$, $2.52{\times}10^{-4}sec^{-1}$, and activation energy was $0.75kcal{\cdot}mol^{-1}$ and $0.70kcal{\cdot}mol^{-1}$ at $20^{\circ}C$, respectively.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.298-303
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• 2007

Several combinations of ozone based advanced oxidation processes were tested for the treatment of red water (RW) containing recalcitrant chemical pollutants produced from 2,4,6-trinitrotoluene (TNT) manufacturing process. $O_3$, $UV/O_3$, $UV/O_3/H_2O_2$, $UV/O_3/H_2O_2/Fe^{2+}$ processes were tested for the treatment of RW. The order of organic and color removal efficiency was found to be : $O_3{\leq}UV/O_3$ < $UV/O_3/H_2O_2$ < $UV/O_3/H_2O_2/Fe^{2+}$. The optimum conditions for the removal of organic and color in the $UV/O_3/H_2O_2/Fe^{2+}$ process were 0.053 g/min of ozone flow rate, 10 mM of $H_2O_2$ concentration and 0.1 mM of $FeSO_4$ concentration. Organic and color removal efficiencies were 96 and 100 % respectively in the $UV/O_3/H_2O_2/Fe^{2+}$ process. tert-butyl alcohol (t-buOH) was used as the hydroxyl radical scavenger. Enhancement of hydroxyl radical production was achieved by the combination of ozone with several oxidants such as UV, $H_2O_2$, $Fe^{2+}$.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.103-111
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• 2000

Ozonation and advanced oxidation($H_2O_2/O_3$) process were investigated under various experimental conditions to improve the efficiency of biological filter used for the treatment of recycled wastewater from aquaculture. Ammonia removal followed the first-order reaction whose reaction rate constant(k) was $2.0{\times}10^{-2}min^{-1}$ in ozonation. The ammonia removal rate increased according as the bicarbonate alkalinity is increased. About 46% $NH_3$ was oxidized by ozone at 200 mg/L as $CaCO_3$. When alkalinity existed in wastewater, ammonia removal rate by advanced oxidation was very low due to the inhibition effect of bicarbonate. However, when initial pH was adjusted to about 8.2 by 0.1 N KOH, ammonia removal rate was improved higher than that by ozonation. Especially. ammonia removal rate was the highest at $H_2O_2/O_3$ of 0.25 and about 90% of ammonia was removed in 30 min at this ratio as pH was maintained over 9. In the case of wastewater containing ammonia and organic constituents, ammonia removal efficiency by both ozonation and advanced oxidation decreased seriously because organic constituents consumed the oxidant faster than ammonia. In addition the optimal $H_2O_2/O_3$ ratio was changed. Like ammonia removal, DOC(dissolved organic carbon) increased for first 10 min and then decreased slowly because the particulate organic constituents were oxidized rapidly and then produce DOC. Even when the ammonia concentration by twice, oxidation of DOC was not retarded.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.11-17
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• 1999

This experiment was conducted to select and utilize the tolerant rice varieties for ozone stress through comparing the physiological responses. In SOD activity, Backunchalbyeo which treated once by 0.15 ppm $0_3$, Ilpumbyeo and Inbujinado treated twice showed significantly different SOD activity compared with $non-O_3$ treatment. No significant difference of SOD activity in three-times $0_3$ treated Sangnambatbyeo and Hangangchalbyeo was found as compared to ($non-O_3$ treated)control, POD activity, when Sangnammbatbyeo, Hangsngchalbyeo, Ilpumbyeo and Inbujinado were sequently treated by third ozone, showed no significant difference between $O_3$ treatment and $non-O_3$. In the comparison of amino acid content in rice leaf blade between three times $O_3$ treatment and $non-0_3$ treatment in 3 varieties, phenylalanine content represent as increased quantities. Especially, in three times $0_3$ treatment of Sangnambatbyeo, phenylalanine content(O.66 mg/g) was significantly increased as compared with $non-O_3$. Visual-growing characters of Sangnembatbyeo were significantly different between $0_3$ treatment and non-treatment. However, grain-filling rate showed no difference. SOD and POD related to resistant mechanism were high activity. In addition, phenylalanine known as precursor which is synthesized resistant materials was increased by $0_3$ treatment. These results suggested that Sangnambatbyeo which increased SOD and POD activity, and phenylalanine content under ozone stress could be selected as a tolerant variety.

• Food Engineering Progress
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• v.14 no.4
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• pp.316-321
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• 2010

The efficacy of the ozonated water (0.1, 0.2, 0.4, 0.6, and 1.0 ppm) in reducing the risk of food-borne disease was investigated in this study. After inoculation of Listeria monocytogenes (ATCC 19112), Salmonella enterica subsp. enterica biovar Typhimurium (ATCC 12598), Escherichia coli O157:H7 (ATCC 43890) to lettuce, spinach, and beef, inhibition effect with different washing concentrations, time, and methods with ozonated and tap water were evaluated. As a result, there were 2.16 to 3.85 log CFU/mL reduction in different foods and 7 log CFU/mL reduction on cutting boards after watering with ozonated water. Higher than 0.2 ppm of ozonated water treatment reduced the growth of food-borne disease bacteria with increasing washing time and ozone concentration. These results suggested that the ozonated water treatment effectively improved the microbiological quality and food safety.

• Journal of the Korean earth science society
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• v.23 no.8
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• pp.683-696
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• 2002

In this work. we investigated the ozone data sets that exceeded ambient air quality standards from 31 air quality monitoring stations dispersed across the Seoul metropolitan city during the period covering 1990 and 2000. To specifically describe spatial dependency of high level O$_3$ occurrence, we grouped our data into four different geographical ozone exceedance is much longer in SW than the other three sectors. When we compared the exceedance data in terms of occurrence frequency, the month of maximum frequency differed slightly among different sectors. Examination of long-term exceedance trend indicated that its frequency increased continuously from all sectors over the past years, although slightly opposite patterns existed in their absolute values. Most importantly, its peak occurrence frequency seemed to center in very recent years such as 1998 (NE sector) and 2000 (ail pattern sectors except NE). Consequently, we were able to describe the existence of certain patterns of ozone exceedance data sets in terms of both temporal and spatial scales.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.338-343
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• 1997

The response of seventy-five rice cultivars to ozone (O$_3$) were tested in the open-top chamber with ozone producing and monitoring system to determine the varietal difference of resistance to $O_3$ stress. Ozone was produced by electrostatic discharge in oxygen and was monitored by UV absorption ozone analyzer. Difference in response of rice to ozone was more clearly appeared on rice plants treated for 2 to 4 hours at 0.3 ppm concentration of $O_3$. Varietal resistance of rice to ozone was more distinctly classified at 21- to 35-day seedlings compared with 14-day rice plants. Most of indica and Tongil(indica$\times$japonica) type rice cultivars were more resistant than that of japonica cultivars based on the leaf injury to $O_3$. Eight Korean cultivars belong to japonica groups showed highly resistant reaction to $O_3$. Ozone exposure during booting stage caused lower grain fertility than exposures during seedling, maximum tillering and heading stages of rice.

• Analytical Science and Technology
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• v.13 no.5
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• pp.652-658
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• 2000

Chemical degradation of aqueous humic acid by ozonation was studied with respect to the direct reactions of ozone and the indirect reactions due to its preliminary decomposition to secondary oxidant, OH radical. This was characterized by analyzing TOC, $UV_{254}$ and ozone consumption measured in different experimental conditions in which ozone reacted in the presence of various concentrations of $H_2O_2$ and $HCO_3{^-}$ concentrations ranging from 20 to 100 mg/L. and different pH (5-9). The results suggest that the TOC removal is mainly dependent on indirect reactions of OH radical whereas $UV_{254}$ reduction is mainly dependent on direct reactions of ozone with humic acid molecules. It has been also found that ozone consumption was most likely to be affected by pH and alkalinity in the solution.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.123-124
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• 2000

오존($O_3$)은 이산화질소, 일산화탄소, 휘발성유기화합물 둥을 포함하는 다양한 물질과 광화학반응에 의하여 생성되는 2차적인 오염물질로 사람과 식물에 영향을 미치고 있는 중요한 오염물질로 알려지고 있으며, 국내에서는 이와 관련하여 오존예보제, 경보제 둥을 운영하여 오존에 의한 피해 영향을 줄이고자 노력하고 있다. 현재 오존을 측정할 수 있는 방법은 환경오염공정시험방법과 정부에서 운영하고 있는 대기오염 자동측정망의 오존 측정방법인 자외선광도법(Ultra Violate Photometric Method)으로 구분되어 지고 있으나, 자동측정장비는 매우 고가의 장비이며, 관리를 위하여 전문적인 지식이 요구되고 있고, 측정소의 개수가 매우 부족한 실정이기 때문에 대기중 오존농도의 지역적인 자료와, 실내공기 측정, 그리고 공간적인 분포 해석을 위해서는 다른 측정방법이 요구된다고 하겠다. (중략)