• Atmosphere
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• v.30 no.1
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• pp.91-102
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• 2020

MERRA-2 ozone and atmospheric data are utilized to test the usefulness of reanalysis-based tracer transport analysis for ozone in the tropical tropopause layer (TTL). Transport and mixing processes related to the seasonal variation of TTL ozone are examined using the tracer transport equation based on the transformed Eulerian mean, and the results are compared to previously proposed values from model analyses. The analysis shows that the seasonal variability of TTL ozone is mainly determined by two processes: vertical mean transport and horizontal eddy mixing of ozone, with different contributions in the Northern and Southern Hemispheres. The horizontal eddy mixing process explains the major portion of the seasonal cycle in the northern TTL, while the vertical mean transport dominates in the southern TTL. The Asian summer monsoon likely contributes to this observed difference. The ozone variability and related processes in MERRA-2 reanalysis show qualitatively similar features with satellite- and model-based analyses, and it provides advantages of fine-scale analyses. However, it still shows significant quantitative biases in ozone budget analysis.

• Journal of Korean Society on Water Environment
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• v.34 no.2
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• pp.149-156
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• 2018

Oxidation of Ciprofloxacin, Trimethoprim, and Enrofloxacin by ozone was experimentally investigated to observe the effects of background water quality (such as ultrapure water, humic acid, and biologically treated wastewater) and water temperature on the removal rate of these antibiotics, and, thereby, to be able to provide design information when the ozone treatment process is adopted. Initial concentrations of the antibiotics spiked to $10{\mu}g/L$, and the ozone dose was 1, 2, 3, 5, and 8 mg/L. While the removal rate of Ciprofloxacin under ultrapure water background by ozone oxidation was over 99%, the removal rate under humic acid and biologically treated wastewater background was markedly lower, in the range of 49.3% ~ 99% and 19.8 % ~ 99 %, respectively. When water temperature is decreased from $20^{\circ}C$ to $4^{\circ}C$, the removal rate is reduced from the range of 19.8% ~ 99 % to the range of 7.5 % ~ 99 % under a biologically treated wastewater background. The effects of background and temperature on the removal rate of Trimethoprim and Enrofloxacin were similar to that of Ciprofloxacin, but the degree was different. Therefore, it is concluded that the background of water to be treated, as well as water temperature, should be taken into consideration when the design factor, such as ozone dose, is determined, so that the treatment objective of the ozone treatment process can be most effectively met.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.4
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• pp.347-356
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• 2017

Oxidation of erythromycin, sulfamethazine and sulfathiazole by ozone was experimentally investigated to see the effects of background water quality such as ultrapure water, humic acid and biologically treated wastewater and water temperature on the removal rate, consequently to provide design information when the ozone treatment process is adopted. Initial concentration of the antibiotics was spiked to $10{\mu}g/l$ and ozone dose was 1, 2, 3, 5, 8 mg/l. While the removal rate of erythromycin under ultrapure water background by ozone oxidation was over 99%, that under humic acid and biologically treated wastewater background was markedly reduced to the range of 59.8%~99% and 17.0%~99%, respectively. When water temperature is decreased from $20^{\circ}C$ to $4^{\circ}C$, the removal rate is reduced from the range of 17.0%~99% to the range of 9.4%~97.4% under biologically treated wastewater background. The effects of background and temperature on the removal rate of sulfamethazine and sulfathiazole were similar to erythromycin, but the degree was different. Therefore, it is concluded that the background of water to be treated as well as water temperature should be taken into consideration when the design factor such as ozone dose is determined to meet the treatment objective in the ozone treatment process.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.362-363
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• 2003

Photochemical ozone is formed from nitrogen oxides (NOx) and volatile organic compounds(VOCs) through non-linear interactions between chemical reactions and meteorology, and the relationship between precursors and photochemical ozone will be changed to match the emission distribution and meteorological fields. It is generally known that for some conditions the process of ozone formation is controlled almost entirely by NOx and is largely independent of VOC, while for other conditions ozone production increases with increasing VOC and does not increase(or sometimes even decreases) with increasing NOx (omitted)

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2001-2003
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• 1999

Recently the ozone generation system is well used for cleaning the contaminated water by using the strong oxidization effects of ozone. Ozone generation system is composed of ozone generation device, air or oxygen supply device and high voltage apply device. In this paper, commercial frequency was applied to the wire typed conductor. The ozone concentration was measured with air or oxygen as a supplied gas, which can be used as basic data for the development of ozonizer system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.94-98
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• 2012

The behavior of ozone micro bubble cleaning system was investigated to evaluate the solution as a new method of solar cell wafer cleaning in comparison with former conventional RCA cleaning. We have developed the ozone dissolution system in the ozonated water for more efficient cleaning conditions. The optimized cleaning conditions for solar cell wafer process were 10 ppm of ozone concentration and 12 minutes in cleaning periods, respectively. We have confirmed the cleaning reliability and cell efficiencies after ozone micro bubble cleaning. Using this new cleaning technology, it was possible to obtain higher efficiency, higher productivity, and fast tact time for applying cleaning in the fields on bare ingot wafer, LED wafers as well as the solar cell wafer.

• Journal of Korean Society on Water Environment
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• v.24 no.1
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• pp.86-90
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• 2008

Water reuse of effluent is limited, due to bacteria and chromaticity or turbidity which may result in low perception of water quality. Consequently, this study showed a method in the reuse of treated wastewater by a diversified treatment method, with separation of centralized reformation of aeration tank into pre-treatment with minimum installation of facilities, and post-treatment, applying advanced oxidation treatment. A pilot plant experiment was performed using Sym-Bio process adopting an NADH Sensor without modification of the exiting aeration tank. The Dissolved Ozone Flotation process, which is an advanced oxidation process, to treat the remaining organics, nutrients, chromaticity, turbidity and bacteria. As a result in the Sym-Bio process, the biological treatment, even on the condition of single stage reaction tank, the treatment efficiencies of BOD, $COD_{Mn}$, $COD_{Cr}$, SS and T-N were 96.6%, 84.6%, 88.25%, 95.1% and 71.0%, respectively, while that for T-P was 25.0%, which required further treatment. In the Dissolved Ozone Flotation process, the advanced oxidation treatment, the treatment efficiencies of BOD, $COD_{Mn}$, $COD_{Cr}$, SS, T-N, T-P, chromaticity, turbidity, bacteria, coliforms were 78.9%, 34.6%, 28.7%, 48.0%, 70.4%, 82.4%, 84.0%, 74.5%, 99.8% and 99.4%, respectively.

• The Journal of Natural Sciences
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• v.10 no.1
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• pp.103-109
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• 1998

We studied on the decoloring effect of viscose rayon by vapor type ozone processing using ozone's strong oxidation. When ozone is generated, it becomes high concentration in vapor state, but in the insolving process with water, there are a lot of lose of ozone. As a result, a study using ozone in vapor-high concentration state is needed. So, in this paper, vapor type ozone processing is used unlike previous ozone treatment method-an aqueous solution method-to get a good effect from shortening the processing time. When vapor type ozone processing was directly treated to fabrics, high concentration ozone was generated then in a short time oxidized a dye existed in fabrics and finally decolored it. As vapor type ozone did not directly response to an organic dye, viscose rayon's decolorization was to be studied by changing pick up ratio(60%, 50%, 40%, 30%, 20%) using water as a medium. When pick up ratio of water was 40%, fabric's whiteness was improved but tensile strength and elongation were reduced. So 60 minutes was assumed as the most adjust time to minimize the reduction of fabric's tensile strength and elongation moreover of maximize the improvement of whiteness.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.5
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• pp.583-594
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• 2003

Ozone is an important atmospheric pollutant that is occurred in tropospheric chemical process and it also affects the human health and plants. For a correct application of abatement strategies for ozone, it is necessary to understand the factors that control atmospheric ozone removal by dry deposition processes. The present study investigates the numerical simulation of the dry deposition velocity (V$^{d}$ ) obtained from PNU/DEM (Pusan National University Deposition Model). PNU/DEM includes seasonal categories, meteorological factors, surface properties and land-use types and proposes for an accurate numerical computation. And, this study examines the ability of the PNU/DEM to compute V$_{d}$ of ozone over water surfaces and evaluates PNU/DEM by comparing its estimated V$_{d}$ to past observed V$_{d}$ over water. The parametrization was found to yield V$_{d}$ values generally in good agreement with the observations for the deciduous forest and the coniferous forest. Ozone is removed slowly at wet surface or water due to its low water solubility. Therefore V$_{d}$ values over water were lower than Vd values over the other surfaces. Comparison of PNU/DEM simulated V d values to observations of ozone V$_{d}$ that have been reported in the literature implies that PNU/DEM produces realistic results.

• Journal of Soil and Groundwater Environment
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• v.15 no.2
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• pp.34-39
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• 2010

In this study, the remediation of diesel contaminated soil was attempted with ozone treatment and Fenton reaction. About 10% of initial diesel concentration was removed by the ozone saturated solution. The pseudo-first order decomposition constant of diesel contaminated soil in the presence of 5% of hydrogen peroxide with 1.82, 2.82, 4.82, 6.82, and 11.82% of iron contents was 0.0228, 0.0308, 0.0482, 0.0471, and 0.0592 $min^{-1}$ respectively. The decomposition constant of the diesel was 0.0064 $min^{-1}$ with the addition of ozone saturated solution only. On the addition of ozone saturated solution in the presence of 5% hydrogen peroxide and 5% iron, the decomposition constant of the diesel was 0.0850 $min^{-1}$. These results indicated that the decomposition rate was 190% faster than without the addition of ozone saturated solution. Thus, the application of both ozone and the fenton reaction is promising for the remediation of the diesel contaminated soil.