• Journal of Environmental Health Sciences
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• v.44 no.6
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• pp.539-547
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• 2018

Objectives: Ozone ($O_3$) advisories are issued by provincial/prefectural and city governments in Korea and Japan when oxidant concentrations exceed the criteria of the related country. Advisories issued only after exposure to high $O_3$ concentrations cannot be considered ideal measures. Forecasts of $O_3$ would be more beneficial to citizens' health and daily life than real-time advisories. The present study was undertaken to present a simplified forecasting model that can predict surface $O_3$ concentrations for the afternoon of the day of the forecast. Methods: For the construction of a simple and practical model, a multivariate regression model was applied. The monitored data on gases and climate variables from Japan's air quality networks that were recorded over nearly one year starting from April 2016 were applied as the subject for our model. Results: A well-known inverse correlation between $NO_2$ and $O_3$ was confirmed by the monitored data for Iksan, Korea and Fukuoka, Japan. Typical time fluctuations for $O_3$ and $NO_x$ were also found. Our model suggests that insolation is the most influential factor in determining the concentration of $O_3$. $CH_4$ also plays a major role in our model. It was possible to visually check for the fit of a theoretical distribution to the observed data by examining the probability-probability (P-P) scatter plot. The goodness of fit of the model in this study was also successfully validated through a comparison (r=0.8, p<0.05) of the measured and predicted $O_3$ concentrations. Conclusions: The advantage of our model is that it is capable of immediate forecasting of surface $O_3$ for the afternoon of the day from the routinely measured values of the precursor and meteorological parameters. Although a comparison to other approaches for $O_3$ forecasting was not carried out, the model suggested in this study would be very helpful for the citizens of Korea and Japan, especially during the $O_3$ season from May to June.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.5
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• pp.642-652
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• 2006

In order to understand the characteristics of surface ozone concentration and high $O_3$ concentration days, regional data from seven air quality monitoring stations which were operated by local governments were analyzed Regional characteristics of $O_3$ concentration were analyzed with the data of $O_3$ concentration and the characteristics of $O_3$ generation and weather conditions by the selection of the days in which the concentration was higher than 80 ppb. In the case of daily variation, the lowest $O_3$ concentration was shown in all regions from 7am to 8am and the highest around at 4 pm. The monthly variation of mean $O_3$ concentration and ${\Delta}O_3$ values revealed a reducing pattern in July and August following the peak in June, and again a gradual increasing trend in September and October. The result shows that the amount of ozone is dependent on photochemical reaction. The days of $O_3$ generated more than 80 ppb in the region of Gwangyang-bay were 544 days(1,760 hrs). The frequency of occurrence in the region revealed a strong pattern with the order of Samil-dong, Jinsang, and Gwangmu-dong stations in the Gwangyang region. However, Tein-dong, which is the nearest station to air pollution material generation source, showed the lowest frequency in the study area. Consequently, the meteorological parameters which can easily generate the high concentration of $O_3$ in the region of Gwangyang-bay are characterized as follows; atmospheric temperature which is higher than $19^{\circ}C$, relative humidity with the range of $60{\sim}85%$, the less average wind velocity than 5 m/s, cloud cover which is less than 5/10, and the more duration of sunshine than 8 hours.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.11a
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• pp.59-62
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• 2002

Recently, advanced system for water and wastewater treatment is introduced and operated because of water pollution and etc. One of this System makes use of O3(Ozone) for water and wastewater treatment. In airtight concrete structure, waterproofing phase as well as water are affected by strong oxidative O3 in the long-term. For this reason, material stability against O3 is examined. Consequently, the purpose of this study is to find out material stability an object of epoxy resin by way of accelerated O3 testing.

• Environmental Engineering Research
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• v.11 no.2
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• pp.84-90
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• 2006

UV-catalytic oxidation technique was applied for the treatment of bio-refractory character of the leachate, which is generally present in the form of adsorbable organic halogens (AOX). Destruction of AOX was likely to be governed by pH adjustment, quantitative measurement of oxidants, and the selection of oxidation model type. Peroxide induced degradation ($UV/H_2O_2$) facilitated the chemical oxidation of organic halides in acidic medium, however, the system showed least AOX removal efficiency than the other two systems. Increased dosage of hydrogen peroxide (from 0.5 time to 1.0 time concentration) even did not contribute to a significant increase in the removal rate of AOX. In ozone induced degradation system ($UV/O_3$), alkaline medium (pH 10) favored the removal of AOX and the removal rate was found 11% higher than the rate at pH 3. Since efficiency of the $UV/O_3$ increases with the increase of pH, therefore, more OH-radicals were available for the destruction of organic halides. UV-light with the combination of both ozone and hydrogen peroxide ($UV/H_2O_2$ 0.5 time/$O_3$ 25 mg/min) showed the highest removal rate of AOX and the removal efficiency was found 26% higher than the removal efficiency of $UV/O_3$. The system $UV/H2O_2/O_3$ got the economic preference over the other two systems since lower dose of hydrogen peroxide and relatively shorter reaction time were found enough to get the highest AOX removal rate.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.5
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• pp.611-619
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• 2003

Characteristics of the ozone concentrations in Seoul were analyzed for the data between May and September from 1996 to 2000. Observation data from 27 stations in Seoul are used. Among the results from 27 stations, representative results from 2 stations (City hall and Gwanak representing downtown and background areas of Seoul, respectively) are presented. The 24-hour average ozone concentrations of Gwanak (28.6 ppb) are higher than City hall (14.9 ppb). The 24-hour average ozone concentrations on Sunday are higher than other days at both sites. During weekday, the 24-hour average ozone concentrations on Wednesday are higher than other days. Although the mean of the I-hour daily maximum ozone concentrations at Gwanak is higher than City hall, the . ozone concentrations above 95th percentile at City hall are higher than Gwanak. As a result, the number of days on which the 1 - hour ozone concentration exceeding 100 ppb and 120 ppb at Gwanak (17 and 3) are lower than City hall (29 and 9). To sum up, both sites are VOCs limited region and the mean ozone concentration in Gwanak is higher because of the lower N0$_2$ concentration. But high ozone cases occur more frequently in City hall when conditions are right.

• Journal of Environmental Science International
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• v.31 no.8
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• pp.677-689
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• 2022

In order to photocatalytically treat organic matter (COD_Cr) and chromaticity effectively, chemical coagulation and sedimentation processes were employed as a pretreatment of the leachate produced from landfill in Jeju Island. This was performed using FeCl₃·6H₂O as a coagulant. For the treated leachate, UV/TiO₂ and UV/TiO₂/H₂O₂ systems were investigated, using 4 types of UV lamps, including an ozone lamp (24 W), TiO₂ as a photocatalyst, and/or H₂O₂ as an initiator or inhibitor for photocatalytic degradation. In the chemical coagulation and sedimentation process using FeCl₃·6H₂O, optimum removal was achieved with an initial pH of 6, and a coagulant dosage of 2.0 g/L, culminating in the removal of 40% COD_Cr and 81% chromaticity. For the UV/TiO₂ system utilizing an ozone lamp and 3 g/L of TiO₂, the optimum condition was obtained at pH 5. However, the treated COD_Cr and chromaticity did not meet the emission standards (COD_Cr: 400 mg/L, chromaticity: 200 degrees) in a clean area. However, for a UV/TiO₂/H₂O₂ system using 1.54 g/L of H₂O₂ in addition to the above optimum UV/TiO₂ system, the results were 395 mg/L and 160 degrees, respectively, which were within the emission standard limits. The effect of the UV lamp on the removal of COD_Cr, and chromaticity of the leachate decreased in the order of ozone (24 W) lamp > 254 nm (24 W) lamp > ozone (14 W) lamp > 254 nm (14 W) lamp. Only COD_Cr and chromaticity treated with the ozone (24 W) lamp met the emission standards.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.6
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• pp.545-554
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• 1998

The diurnal variation of O3 concentration shows two peaks, the first peak at noontime and the secondary peak at night. In order to show why the secondary peak, high nocturnal O3 concentration, occurs without sunlight which is a essential factor of a photochemical response, the O3 concentration, several weather elements and synoptic weather map were used for June∼September at 1995, 1996. The mean concentration of high nocturnal O3 concentration days is higher by 5.4 ppb than that of low nocturnal O3 concentration days. The nocturnal O3 concentration is higher than that of diurnal O3 concentration during high nocturnal O3 concentration days, at July, 1995 and June, 1996. The high nocturnal O3 concentration is related to low air pressure, high cloud cover and high wind speed. The correlation coefficient, r. between nocturnal O3 concentration and wind speed, pressure and cloud cover is 0.387, -0.218, and 0.194, respeftiviely. It is interesting that the O3 concentration increases at Pusan when the typhoon passes by. The same result showed at Taegu when the typhoon FAYE passed by. According to the analysis of nocturnal O3 concentration for June∼September at 1995 and 1996, it seems that the high nocturnal O3 concentration relates to the trough and cyclones passing by Pusan.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.73-79
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• 2011

The annals of Joseon Dynasty is one of the UNESCO's Memory of the World Register. For the safety preservation of wax applied volumes of the annals of Joseon Dynasty, the aging behavior of beeswax and beeswaxed Hanji with $CO_2$, $O_3$, $SO_2$ and $NO_2$ gas has been evaluated. The weight loss of beeswaxed Hanji after aging under ozone gas were increased because of strong acidity of ozone. The acid value and relative intensity of carbonyl groups in beeswax were stabilized with aging time. The physical strength of dewaxed Hanji after ozone aging were rapidly decreased by aging time. The crystallinity of dewaxed Hanji were stabilized at all aging times.

• 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.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.1
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• pp.50-62
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• 2011

Temporal trends and spatial distributions of ozone concentrations in Pohang were investigated using data measured at 4 air quality monitoring stations (i.e., Daedo, Jukdo, Jangheung, and Desong) during 2002-2006. The monthly mean ozone concentrations were highest during April and June and decreased during July and August, which follows the typical trend in the Northeast Asia region. The high springtime ozone concentration might have been strongly influenced by the enhanced photochemical ozone production of accumulated precursors during the winter under increased solar radiations. In July and August, ozone levels were decreased by frequent and severe precipitation that caused lower mean monthly solar radiation and efficient wash-out of ozone precursors. This suggests that precipitation is extremely beneficial in the aspect of ozone pollution control. High ozone concentrations exceeding 80ppb dominantly occurred in May and June during the late afternoon between 16:00~17:00. Ozone concentrations were higher in Jangheung and Daesong relative to Daedo and Jukdo, whereas total oxidants $(O_3+NO_2)$ were higher in Jangheung and Daedo. In the suburban area of Daesong, ozone concentrations seem to be considerably higher than those in urban sites of Daedo and Jukdo due to lower ozone loss by NO titration with lower local NO level.