• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2007년도 추계학술대회 논문집
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• pp.85-86
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• 2007

• 한국환경과학회지
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• 제23권2호
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• pp.261-274
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• 2014

This work investigates the relationship between the sea breeze circulation and ozone concentrations during cold water events in the southeastern coastal area of the Korean Peninsula, where coastal upwelling frequently occur. This analysis was performed based on the classification of two categories, such as cold water and non-cold water events, over the period of 2000-2009. The low air temperature ($0.5^{\circ}C$), low SST ($5^{\circ}C$) and the wind direction(southerly) are the features of the cold water events in the Southeastern coastal area. Moreover, ozone concentrations in the cases of the sea breeze circulation and cold water events were significantly lower (below 30 ppb) than those (70~100 ppb) in the non-clod water events, because of the low air temperature ($10{\sim}20^{\circ}C$) and high wind speed (3~5 m/s) around the southeastern coastal area.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권7호
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• pp.533-541
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• 1999

Multi-discharge type ozonizer(MDO) using superposed silent discharge has been designed and manufactured. It consists of three electrodes( central electrode, internal electrode, and external electrode ) and double gaps( gap between central electrode and internal electrode, gap between internal electrode and external electrode ). Therefore, ozone is generated by superposing silent discharges generated between the gaps respectively. And the MDO consists of three types of superposed discharge ozonizers according to voltage appling method for each electrode ; A.C. high voltages are applied two of three electrodes with phase difference of 180[˚], the other electrode is a ground. This paper describes that discharge and ozone generation characteristics of MDO which comprising central electrode and internal electrode applied A.C. high voltages with phase difference of 180[˚] respectively, and the grounded external electrode. As a result, the maximum ozone concentration, generation, and yield can be obtained 10208[ppm], 6.4[g/h], and 280[g/kwh] respectively.

• Journal of Biosystems Engineering
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• 제30권1호
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• pp.17-24
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• 2005

An efficient microbial control system was introduced into a garlic peeling system using pressurized water in order to improve the quality and the shelf-life of peeled garlic. High microbial density of the spoiled peeled garlic and the water used for peeling and washing indicated that an efficient microbial control system is necessary far the peeling system. Though Pseudomonas spp. and Penicillium spp. were closely related to the spoilage of peeled garlic, the spoilage of peeled garlic was thought to be caused mainly by nonspecific increase in microbial density. The shelf-life of the garlic peeled by pressurized water was longer than that of the garlic peeled by pressurized air, and the degree of damage had great effect on the shelf-life of peeled garlic. Ozonated water was effective in decreasing the microbial contamination and in increasing the shelf-life of peeled garlic. Based on the findings of the study, following improvements were made to the garlic peeling system using pressurized water; 1) the water circulation system was modified in order to completely separate the water for washing from the water for garlic peeling, 2) filtration and cooling equipments were introduced into the circulation system of the water for peeling, and 3) an ozone generator which could continuously supply ozonated water (dissolved ozone concentration of 0.4 ppm) was attached to the circulation system of the water for washing.

• 한국대기환경학회지
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• 제28권3호
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• pp.249-260
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• 2012

Monitoring of climate change and atmospheric environment by satellite measurements has been increased in recent years. In this study, nitrogen dioxide ($NO_2$) measurements from Ozone Monitoring Instrument (OMI) were compared with surface measurements over the Korean peninsula. $NO_2$ from OMI measurements showed high values and also showed seasonal variations such as high concentration in winter and low in summer over metropolitan areas while $NO_2$ concentration at national background station was low and did not clearly show seasonal variations. Surface measurements showed similar temporal and spatial variations to those of satellite measurement. The comparison between satellite measurements and surface measurements showed that the correlation between them was higher in urban area (r=0.64 at Seoul and r=0.63 at Daegu) than in national background stations (r=0.37 at Jeju) because the concentration in urban area was relatively high so that the variation of $NO_2$ concentration could be detected better than at national background stations by satellite. Satellite can effectively measure the emission and transport of pollutants with no limitations in spatial coverage.

• 한국대기환경학회지
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• 제26권5호
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• pp.475-489
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• 2010

In order to verify the enhancement of ozone and carbon monoxide (CO) during springtime in East Asia, we investigated weather conditions and data from remote sensors, air quality models, and air quality monitors. These include the geopotential height archived from the final (FNL) meteorological field, the potential vorticity and the wind velocity simulated by the Meteorological Mesoscale Model 5 (MM5), the back trajectory estimated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the total column amount of ozone and the aerosol index retrieved from the Total Ozone Mapping Spectrometer (TOMS), the total column density of CO retrieved from the Measurement of Pollution in the Troposphere (MOPITT), and the concentration of ozone and CO simulated by the Model for Ozone and Related Chemical Tracers (MOZART). In particular, the total column density of CO, which mightoriginate from the combustion of fossil fuels and the burning of biomass in China, increased in East Asia during spring 2000. In addition, the enhancement of total column amounts of ozone and CO appeared to be associated with both the upper cut-off low near 500 hPa and the frontogenesis of a surface cyclone during a weak Asian dust event. At the same time, high concentrations of ozone and CO on the Earth's surface were shown at the Seoul air quality monitoring site, located at the surface frontogenesis in Korea. It was clear that the ozone was invaded by the downward stretched vortex anomalies, which included the ozone-rich airflow, during movement and development of the cut-off low, and then there was the catalytic photochemical reaction of ozone precursors on the Earth's surface during the day. In addition, air pollutants such as CO and aerosol were tracked along both the cyclone vortex and the strong westerly as shown at the back trajectory in Seoul and Busan, respectively. Consequently, the maxima of ozone and CO between the two areas showed up differently because of the time lag between those gases, including their catalytic photochemical reactions together with the invasion from the upper troposphere, as well as the path of their transport from China during the weak Asian dust event.

• 한국환경과학회지
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• 제32권5호
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• pp.285-301
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• 2023

This study analyzed characteristics of ozone (O₃) formation regimes in Busan over a period of recent five years (2015~2019) and compared the findings with those obtained in Seoul. We employed four observed variations: early morning commuting-hour (i.e., 06:00-09:00 LST) nitrogen dioxide (NO₂), peak-hour (i.e., 12:00-16:00 LST) O₃, 8-hour average O₃ (MDA8 O₃), and △O₃ (=O_{3_max}- O_{3_min}) in Busan and Seoul. In addition, the NO₂-O₃ relation was assessed to interpret which of NOx-limited or volatile organic compound (VOC)-limited was dominant. In Busan, the annual mean O₃ concentration was relatively higher than in Seoul, whereas there were fewer high-concentration days. The Pearson correlation coefficients (R) between Early morning-hour NO₂ and the Peak-hour O₃ was positive (but close to zero) in Busan and negative in Seoul. Likewise, the R between the Early morning-hour NO₂ and the △O₃ showed a relatively considerable positive correlation (R=+0.4~0.5)(R=+0.4~0.5) in Busan, while a weak positive correlation (R=+0.1~0.2) in Seoul. From this result, it can be inferred that the O₃ formation regime in Busan was intrepreted to be nearly neutral or relatively closer to the NO_x-limited regime than Seoul, while Seoul to the VOC-limited regime. The study findings imply that O₃ control strategies should be applied differently in Busan and Seoul. The results here were inferred from surface NO₂ and O₃ observations, and the varification studies based on in-situ VOCs measurements would be needed.

• 한국지반환경공학회 논문집
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• 제23권3호
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• pp.23-29
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• 2022

본 연구에서는 오존의 용해효율 개선과 자가분해 촉진을 위해 나노기포와 초음파 캐비테이션을 동시에 적용한 오존 나노기포 공정을 조사하였다. 공정의 유기물 분해효율을 파악하기 위해 200mm × 200mm × 300mm 규모의 반응기를 제작하여 다양한 조건에서 페놀 분해 실험을 진행하였다. 나노기포의 사용은 60분 반응에서 페놀 분해 효율을 일반적인 폭기 방식에 비해 2.07배 증가시켰으며, 용존 오존의 최대 용해농도를 크게 증가시켜 오존의 용해효율 개선에 효과적이었다. 초음파 조사는 나노기포와 함께 사용될 때 페놀 분해 효율을 36% 증가시켰으며 오존의 자가 분해 촉진으로 용존 오존은 낮게 나타났다. 초음파 출력이 강할수록 페놀 분해 효율도 증가하였으며, 실험에서 사용한 28kHz, 132kHz, 580kHz 중 132kHz의 주파수에서 페놀의 분해 효율이 가장 높게 나타났다. 오존 나노공정은 기존 오존 공정과 같이 높은 pH에서 더 좋은 분해효율을 보였으나 중성에서도 60분 반응 후 페놀 100% 분해를 달성하여 pH에 의한 영향이 적은 것으로 나타났다. 이는 초음파에 의한 오존 자가분해 촉진에 의한 것으로 판단된다. 초음파 조사에 의한 기포 특성 변화를 확인하기 위해 Zetasizer를 이용하여 기포의 크기와 제타 전위 분석을 진행하였으며 초음파 조사가 기포의 평균 크기를 11% 감소시키고 기포 표면의 음전하를 강화하여 오존 나노기포의 물질전달과 수산화 라디칼 생성 효율에 긍정적인 효과를 끼치는 것을 확인하였다.

• 대한환경공학회지
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• 제27권11호
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• pp.1162-1167
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• 2005

축산폐수는 고농도의 난분해성 유기물질을 많이 함유하고 있기 때문에 처리하기가 매우 어려운 것으로 알려져 있다. 따라서 본 연구에서는 현장에 건설된 오존을 이용한 시스템인 DOF(Dissolved Ozone Flotation)와 PO2(Pressurized Ozone Oxidation)에 의한 축산폐수의 처리특성을 조사하였다. DOF-PO2의 유입수내에 존재하는 SS의 제거율은 94%를 상회하여 약 400 mg/L의 농도를 22 mg/L까지 낮출 수 있었다. $COD_{Mn}$의 제거율도 90%정도로 620 mg/L로 유입되어 63 mg/L로 유출되었다. $SCOD_{Cr}$은 890 mg/L 정도가 유입되었으며 82%가 제거되어 160 mg/L 정도로 유출되었다. UV-254흡광도는 96%제거 되었다. 특히 TP의 제거율은 98%가 넘었고 27 mg/L가 유입되어 0.35 mg/L만이 유출되었다. TN도 SS의 제거와 함께 68%정도 제거되었으나 오존에 의한 제거효과는 없었다. DOF-PO2시스템에 의한 고농도 오존산화공정을 미생물처리공정과 같이 적용할 경우 축산폐수처리공정의 방류수 수질기준을 맞출 수 있었다.

• Asian Journal of Atmospheric Environment
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• 제9권2호
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• pp.146-157
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• 2015

Emissions of ozone precursors ($NO_x$ and VOCs) and photochemical ozone creation potentials (POCPs) of VOC emission sources were investigated in the largest port city (i.e., Busan), Korea during the year 2011. This analysis was performed using the Clean Air Policy Support System (CAPSS) national emission inventory provided by the National Institute of Environmental Research (NIER), Korea. For $NO_x$, the emissions from off-road mobile sources in Busan were the most dominant (e.g., $31,202ton\;yr^{-1}$), accounting for about 60% of the total $NO_x$ emissions. The emission from shipping of off-road mobile sources (e.g., $24,922ton\;yr^{-1}$) was a major contributor to their total emissions, amounting to 47% of the total $NO_x$ emissions due to the port-related activities in Busan. For VOCs, the emission source category of solvent usage was predominant (e.g., $36,062ton\;yr^{-1}$), accounting for approximately 82% of the total VOC emissions. Out of solvent usages, the emission from painting was the most dominant ($22,733ton\;yr^{-1}$), comprising 52% of the total emissions from solvent usages. The most dominant VOC species emitted from their sources in Busan was toluene, followed by xylene, butane, ethylbenzene, n-butanol, isopropyl alcohol, and propane. The major emission sources of toluene and xylene were found to be painting of coil coating and ship building, respectively. The value of POCP for the off-road mobile source (61) was the highest in ten major activity sectors of VOC emissions. Since the POCP value of ship transport of off-road mobile source (72) was also high enough to affect ozone concentration, the ship emission can play a significant role in ozone production of the port city like Busan.