• Title/Summary/Keyword: ozone standard

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Inactivation of Infectious Cryptosporidium parvum by Various Disinfectants (다양한 소독제에 의한 감염성 크립토스포리디움 불활성화율 평가)

  • Byun, Seung-Heon;Lee, Mok-Young;Cho, Eun-Ju;Yoon, Tae-Ho;Kim, Tae-Ho;Han, Sun-Hee
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.5
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    • pp.533-539
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    • 2007
  • Cell culture infectivity assay using HCT-8 cell was combined with most-probable-number technique to evaluate the inactivation of Cryptosporidium parvum by various disinfectants, including chlorine, ozone, and UV light. The assay was demonstrated to be as sensitive as animal infectivity assay, which has been considered the "gold standard" for assessing Cryptosporidium oocyst infectivity, and a valuable tool to evaluate inactivation of C. parvum by disinfectants. Bench-scale inactivation study showed that at the condition of $5^{\circ}C$ and pH 7.0, CT value of $1,250mg{\cdot}min/L$ by chlorine and $16mg{\cdot}min/L$ by ozone were required to achieve approximately 1.0 log inactivation of C. parvum, suggesting that even ozone could not be sufficient to inactivate C, parvum at low. temperature. Unlike chlorine and ozone, UV light is very effective to inactivate C. parvum, regardless of temperature. A UV light dose of 2 $mJ/cm^2$ provided at least 3 log inactivation of C. parvum.

Variation of Tracer Distribution During the Antarctic Polar Vortex Breakup Shown in ILAS and ILAS-II Data (ILAS와 ILAS-II 자료에서 나타난 남극 와동 붕괴기간의 미량기체 분포변화)

  • Choi, Wookap;Lim, Kyungsoo
    • Atmosphere
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    • v.20 no.3
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    • pp.367-377
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    • 2010
  • Variation of tracer distribution during the vortex-breakup period in the Antarctic region was observed by the data from the Improved Limb Atmospheric Spectrometer (ILAS) and ILAS-II. All four trace species including methane, nitrous oxide, ozone, and water vapor show similar patterns of vertical gradient in spite of different structures of zonal mean mixing ratio. Timings of vortex breakup on each level are estimated by two different methods, and they are compared with zonal standard deviations following the latitude circle of each trace species. Although the tracers have different chemical life times and sink/source, the zonal standard deviation patterns show remarkable similarities. The zonal standard deviation shown here to measure the zonal asymmetry of tracer distribution is believed to diagnose the timing of the Antarctic polar-vortex breakup reasonably well.

An Analysis of Similarity between Air Quality Monitoring Stations in Busan using Cluster Analysis (군집분석을 활용한 부산지역 오존, PM10 측정소의 유사성 분석)

  • Do, Woo-gon;Jung, Woo-sik
    • Journal of Environmental Science International
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    • v.26 no.8
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    • pp.927-938
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    • 2017
  • This study was conducted to determine correlations and similarity between the ozone and $PM_{10}$ data of 19 air quality monitoring stations in Busan from 2013 to 2016, using correlation and cluster analyses. Ozone concentrations ranged from $0.0278{\pm}0.0148ppm$ at Gwangbok to $0.0378{\pm}0.017ppm$ at Taejongdae and were high in suburban areas, such as Yongsuri and Gijang, as well as in coastal areas, such as Jaw, Gwangan, Taejongdae and Noksan. $PM_{10}$ concentrations ranged from $37.2{\pm}25.0ug/m^3$ at Gijang to $58.3{\pm}32.2ug/m^3$ at and Jangrim. $PM_{10}$ concentrations were high in the west, exceeding the annual ambient air quality standard of $50ug/m^3$. Positive correlations were observed for ozone at most stations, ranging from 0.61 between Taejongdae and Sujeong to 0.92 between Bugok and Myeongjang. The correlation coefficients of $PM_{10}$ between stations ranged from 0.62 between Jangrim and Jaw to 0.9 between Gwangbok and Sujeong. Yeonsan, Daeyeon, and Myeongjang were highly correlated with other stations, so they needed to be reviewed for redundancy. Ozone monitoring stations were initially divided into two sections, north-western areas and suburban-coastal areas. The suburban-coastal areas were subsequently divided into three sections. $PM_{10}$ monitoring stations were initially divided into western and remaining areas, and then the remaining areas were subsequently divided into three sections.

Simultaneous Application of Platinum-Supported Alumina Catalyst and Ozone Oxidant for Low-temperature Oxidation of Soot (백금담지 알루미나 촉매와 오존 산화제 동시 적용에 의한 탄소 입자상 물질의 저온 산화반응)

  • Lee, Jin Soo;Lee, Dae-Won
    • Korean Chemical Engineering Research
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    • v.56 no.5
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    • pp.752-760
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    • 2018
  • The lowering of temperature for combustion of diesel particulate matters (or diesel soot) is one of the important tasks in automotive industry that is searching for a way to meet up "high-fuel efficiency, low-emission" standard. In this study, it was discussed how the use of ozone over platinum-based catalyst promotes a low-temperature soot oxidation occurred at $150^{\circ}C$. The use of platinum catalyst did not increase oxidation rate largely but was very effective in improving the selectivity of carbon dioxide. The pre-oxidation of NO into $NO_2$ using ozone was rather crucial in improving the oxidation rate of soot at $150^{\circ}C$.

Comparison of ultrasound-guided subacromial corticosteroid and ozone (O2-O3) injections in the treatment of chronic rotator cuff tendinopathy: a randomized clinical trial

  • Merve Orucu Atar;Nurdan Korkmaz;Sefa Gumruk Aslan;Ozge Tezen;Sinem Uyar Koylu;Yasin Demir;Serdar Kesikburun
    • The Korean Journal of Pain
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    • v.36 no.1
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    • pp.128-136
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    • 2023
  • Background: The authors aimed to compare the effects of a one-time ultrasound (US)-guided subacromial corticosteroid injection and three-time ozone (O2-O3) injection in patients with chronic supraspinatus tendinopathy. Methods: Participants were randomly assigned to the corticosteroid group (n = 22) or ozone group (n = 22). Injections in both groups were administered into subacromial bursa with an US-guided in-plane posterolateral approach. Primary outcome measure was the change in the Western Ontario Rotator Cuff Index (WORC) score between baseline and 12-weeks post-injection. Secondary outcome measures included visual analog scale and Shoulder Pain and Disability Index scores. Assessments were recorded at baseline, and 4-weeks and 12-weeks post-injection. Results: Forty participants completed this study. Based on repeated measurement analysis of variance, a significant effect of time was found for all outcome measures in both groups. Both the groups showed clinically significant improvements in shoulder pain, quality of life, and function. Baseline, 4-week post-injection, and 12-week post-injection WORC scores (mean ± standard deviation) were 57.91 ± 18.97, 39.10 ± 20.50 and 37.22 ± 27.31 in the corticosteroid group, respectively and 69.03 ± 15.89, 39.11 ± 24.36, and 32.26 ± 24.58 in the ozone group, respectively. However, no significant group × time interaction was identified regarding all outcome measures. Conclusions: Three-time ozone injection was not superior to a one-time corticosteroid injection in patients with chronic supraspinatus tendinopathy. It might be as effective as corticosteroid injection at 4-weeks and 12-weeks post-injection in terms of relieving pain and improving quality of life and function.

Comparison of Air Pollution Characteristics in the Center Lane-Bus Stop and the Surrounding Areas (중앙차선 버스 정류장과 주변지역의 대기오염 특성 비교)

  • Lee, Yong-Ki;Kim, Woong-Soo;Hong, Soon-Mo;Shin, Eun-Sang
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.4
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    • pp.378-386
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    • 2014
  • The use of bus stop in the center lane has reduced the emissions of exhaust gas on the road due to the improvement of the traffic speed but has caused a health problem for the citizens who are waiting for the bus in the platform, and thus the air pollution control of bus stop in the center lane is emerging as a more important part. This study was conducted to investigate the air pollution degree for the center lane-bus stops in four regions using mobile air measuring vehicle, and to evaluate the characteristics of air pollution by comparing with the data measured at the urban air monitoring site close to the bus stops. In addition, the correlation analysis was performed to analyze the impact to neighboring region by vehicle exhaust gas. The regional mean concentration of nitrogen dioxide in the center lane-bus stops ranged from 0.025 to 0.043 ppm which shows from 2.5 times to 5.3 times higher than the values of urban air monitoring site selected as a control group. The regional mean concentration of ozone in the center lane-bus stops ranged from 0.023 to 0.034 ppm which shows from 3% to 28% lower than the values of urban air monitoring site selected as a control group. The concentrations of nitrogen dioxide and ozone for the sampling regions did not exceed one hour-air quality environmental standard (0.1 ppm). The mean concentration of particulate matter for four center lane-bus stops was $28{\mu}g/m^3$ which shows about 27% higher than the values of urban air monitoring site selected as a control group, and that of particulate matter did not exceed one day-air quality environmental standard ($100{\mu}g/m^3$). In the results of correlation analysis between data from center lane-bus stops and data from urban air monitoring sites, the correlation coefficient (r) of nitrogen dioxide was relatively low as 0.316 to 0.416, and the correlation coefficient was high as the distance was close and vice versa. However, the correlation coefficient of ozone ranged from 0.167 to 0.658 and the correlation coefficient was high as the distance was far and vice versa.

Investigation of SO2 effect on OMI-TOMS and OMI-DOAS O3 in volcanic areas with OMI satellite data (OMI 위성자료를 이용한 화산지역 고농도 이산화황 환경에서의 TOMS 오존과 DOAS 오존의 비교연구)

  • Choi, Wonei;Hong, Hyunkee;Park, Junsung;Kim, Daewon;Yeo, Jaeho;Lee, Hanlim
    • Korean Journal of Remote Sensing
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    • v.31 no.6
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    • pp.599-608
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    • 2015
  • In this present study, we quantified the $SO_2$ effect on $O_3$ retrieval from the Ozone Monitoring Instrument (OMI) measurement. The difference between OMI-Total Ozone Mapping Spectrometer (TOMS) and OMI-Differential Optical Absorption Spectrometer (DOAS) total $O_3$ is calculated in high $SO_2$ volcanic plume on several volcanic eruptions (Anatahan, La Cumbre, Sierra Negra, and Piton) from 2005 through 2008. There is a certain correlation ($R{\geq}0.5$) between the difference and $OMI-SO_2$ in volcanic plumes and the significant difference close to 100 DU. The high $SO_2$ condition found to affect TOMS $O_3$ retrieval significantly due to a strong $SO_2$ absorption at the TOMS $O_3$ retrieval wavelengths. Besides, we calculated the difference against various $SO_2$ levels. There is the considerable difference (average = 32.9 DU; standard deviation = 13.5 DU) in the high $OMI-SO_2$ condition ($OMI-SO_2{\geq}7.0DU$). We also found that the rate of change in the difference per 1.0 DU change in middle troposphere (TRM) and upper troposphere and stratosphere (STL) $SO_2$ columns are 3.9 DU and 4.9 DU, respectively.

Application of Photocatalytic Degradation for Efficient Treatment of Organic Matter in Landfill Leachate in Jeju Island (제주도 매립장 침출수 중 유기물의 효율적 처리를 위한 광촉매 분해 반응의 응용)

  • Lee, Chang-Han;Lee, Taek-Kwan;Cho, Eun-Il;Kam, Sang-Kyu
    • 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 (CODCr) 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% CODCr 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 CODCr and chromaticity did not meet the emission standards (CODCr: 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 CODCr, 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 CODCr and chromaticity treated with the ozone (24 W) lamp met the emission standards.

Characteristics of Surface Ozone in a Valley Area Located Downwind from Coastal Cities under Sea-breeze Condition: Seasonal Variation and Related Winds (연안 대도시 해풍 풍하측 계곡지역의 지표오존 분포 특성: 계절변화와 바람과의 관계)

  • Kang, Jae-Eun;Oh, In-Bo;Song, Sang-Keun;Kim, Yoo-Keun
    • Journal of Environmental Science International
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    • v.21 no.2
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    • pp.153-163
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    • 2012
  • The seasonal variations of ozone ($O_3$) concentrations were investigated with regard to the relationship between $O_3$ and wind distributions at two different sites (Jung Ang (JA): a semi-closed topography and Seo Chang (SC): a closed topography) within a valley city (Yangsan) and their comparison between these sites (JA and SC) and two non-valley sites (Dae Jeo (DJ) and Sang Nam (SN)) located downwind from coastal cities (Busan and Ulsan). This analysis was performed using the data sets of hourly $O_3$ concentrations, meteorological factors (especially, wind speed and direction), and those on high $O_3$ days exceeding the 8-h standard (60 ppb) during 2008-2009. In summer and fall (especially in June and October), the monthly mean values of the daily maximum $O_3$ concentrations and the number of high $O_3$ days at JA (and SC) were relatively higher than those at DJ (and SN). The increase in daytime $O_3$ concentrations at JA in June was likely to be primarily impacted by the transport of $O_3$ and its precursors from the coastal emission sources in Busan along the dominant southwesterly winds (about 5 m/s) under the penetration of sea breeze condition, compared to other months and sites. Such a phenomenon at SC in October was likely to be mainly caused by the accumulation of $O_3$ and its precursors due to the relatively weak winds under the localized stagnant weather condition rather than the contribution of regional transport from the emission sources in Busan and Ulsan.