간행물
한국환경과학회지 KCI 등재 Journal of Environmental Science International
- 발행기관 한국환경과학회
- 자료유형 학술지
- 간기 월간
- ISSN 1225-4517 (Print)2287-3503 (Online)
- 수록기간 1992 ~ 2023
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제28권 제7호 (2019년 7월) 6건
ORIGINAL ARTICLE
1.
2019.07
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Characteristics of PM10 and PM2.5 Concentrations at Subway Stations in Busan for 3 years (2015∼2017)
This research investigated the characteristics of PM10 and PM2.5 concentrations at the main subway stations in Busan. Annual mean PM10 concentrations at the Seomyeon 1- waiting room and platform were 51.3 ㎍/㎥ and 47.5 ㎍/㎥ , respectively, and the annual PM2.5 concentration at the Seomyeon 1- platform was 28.8 ㎍/㎥ . PM2.5/PM10 ratio at Seomyeon 1-platform and Dongnae station were 0.58 and 0.53, respectively. Diurnal variation of PM10 concentration at subway stations in Busan was categorized into four types, depending on the number of peaks and the times at which the peaks occurred. Unlike the areas outside of the subway stations which reported maximum PM10 concentration mostly in spring across the entire locations, the interiors of the subway stations reported the maximum PM10 concentration in spring, winter, and even summer, depending on their location. PM10 concentration was highest on Saturday and lowest on Sunday. The numbers of days when PM10 concentration exceeded 100 ㎍/㎥ and 80 ㎍/㎥ per day over the last three years at the subway stations in Busan were 36 and 239, respectively. The findings of this research are expected to enhace the understanding of the fine particle characteristics at subway stations in Busan and be useful for developing a strategy for controlling urban indoor air quality.
2.
2019.07
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This research investigated the characteristics of CO, CO2, and NO2 concentrations at main subway stations in Busan. The annual mean CO concentrations at the Suyeong and Nampo stations were 0.75 ppm and 0.48 ppm, respectively. Annual CO2 concentration at the Seomyeon 1- platform was 649 ppm. The NO2 concentrations at the Seomyeon 2- waiting room and the Yeonsan station were 0.048 ppm and 0.037 ppm, respectively. CO concentration was highest at two times of the day, and was proportional to the number of passengers commuting to and from work. The CO and CO2 concentrations were highest in winter, but NO2 concentration was highest in spring. CO and CO2 concentrations were highest on Saturday and lowest on Sunday. The correlation of CO and NO2 concentrations measured at the subway stations with those at the ambient air quality station were highest at the Seomyeon 1 and 2- waiting room and Jeonpodong. The correlation was lowest at the Yeonsan and Yeonsandong station. The number of days when CO2 concentration exceeded 700 ppm over the last three years at the Seomyeon 1- platform was 174. The findings of this research are expected to deepen understanding of the fine particle characteristics at subway stations in Busan and be useful for developing a strategy for controlling urban indoor air quality.
3.
2019.07
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The purpose of this study is to biological treatment of high salinity wastewater using Aerobic Granular Sludge (AGS). In laboratory scale’s experiments research was performed using a sequencing batch reactor, and evaluation of the denitrification reaction in accordance with the injection condition of salinity concentration, surface properties of microorganisms, and sludge precipitability was performed. The results showed that the salinity concentration increased up to 1.5%, and there was no significant difference in the nitrogen removal efficiency; however, it showed a tendency to decrease gradually from 2.0% onward. The specific denitrification rate (SDNR) was 0.052 0.134 mg NO3 --N/mg MLVSS (mixed liquor volatile suspended solid)·day. The MLVSS/MLSS (mixed liquor suspended solid) ratio decreased to 76.2%, and sludge volume index (SVI30) was finally lowered to 57 mL/g. Using an optical microscope, it was also observed that the initial size of the sludge was 0.2 mm, and finally it was formed to 0.8-1.0 mm. Therefore, salinity injection provides favorable conditions for the formation of an AGS, and it was possible to maintain stable granular sludge during long-term operation of the biological treatment system.
4.
2019.07
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This study investigated the relationship between heat-related illnesses obtained from healthcare big data and daily maximum temperature observed in seven metropolitan cities in summer during 2013~2015. We found a statistically significant positive correlation (r = 0.4~0.6) between daily maximum temperature and number of the heat-related patients from Pearson's correlation analyses. A time lag effect was not observed. Relative Risk (RR) analysis using the Generalized Additive Model (GAM) showed that the RR of heat-related illness increased with increasing threshold temperature (maximum RR = 1.21). A comparison of the RRs of the seven cities, showed that the values were significantly different by geographical location of the city and had different variations for different threshold temperatures. The RRs for elderly people were clearly higher than those for the all-age group. Especially, a maximum value of 1.83 was calculated at the threshold temperature of 35℃ in Seoul. In addition, relatively higher RRs were found for inland cities (Seoul, Gwangju, Daegu, and Daejeon), which had a high frequency of heat waves. These results demonstrate the significant risk of heat-related illness associated with increasing daily maximum temperature and the difference in adaptation ability to heat wave for each city, which could help improve the heat wave advisory and warning system.
5.
2019.07
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The purpose of this study was to evaluate the effect of high-salinity wastewater on the microbial activity of Aerobic Granule Sludge (AGS). Laboratory-scale experiments were performed using a sequencing batch reactor, and the Chemical Oxygen Demand (COD), nitrogen removal efficiency, sludge precipitability, and microbial activity were evaluated under various salinity injection. The COD removal efficiency was found to decrease gradually to 3.0% salinity injection, and it tended to recover slightly from 4.0%. The specific nitrification rate was 0.043 0.139 mg NH4 +-N/mg MLVSS·day. The specific denitrification rate was 0.069 0.108 mg NO3 --N/mg MLVSS·day. The sludge volume index (SVI30) ultimately decreased to 46 mL/g. The specific oxygen uptake rate decreased from an initial value 120.3 to a final value 70.7 mg O2/g MLVSS·hr. Therefore, salinity injection affects the activity of AGS, causing degradation of the COD and nitrogen removal efficiency. It can be used as an indicator to objectively determine the effect of salinity on microbial activity.
SHORT COMMUNICATION
6.
2019.07
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We aimed to evaluate antithrombotic efficacy of Protaetia brevitarsis extract during 21 days. Rats (SPF rat, weight 240~260 g) were divided into 16 groups (5 rats per group), they were: control group and Protaetia brevitarsis extract groups with dose of 0.1, 0.5, 1, 2.5, 5, 10, 25, 50, 75, 100, 200, 250, 500, 750, 1,000 mg/kg kg of body weight. Thromboplastin time (PT) and activated partial thromboplastin time (aPPT) as antithrombotic efficacy were tested in this animal experiment (at 7, 14 and 21 days). Overall, the admistration dose of Protaetia brevitarsis extract over 50 mg/kg at 7, 14 and 21 days for PT and over 25 mg/kg at 7, 14 and 21 days for aPPT tented to be longer than that of other groups. In addition, the optimal admistration doses of Protaetia brevitarsis extract to improves antithrombotic efficacy were 75, 100, 200 and 250 mg/kg at 7, 14 and 21 days for PT (p<0.05) and 50 and 100 mg/kg at 7 days, 75 mg/kg at 14 days, or 50, 100, 200 and 250 mg/kg at 21 days for aPPT (p<0.05). It can be concluded that Protaetia brevitarsis extract at optimal levels have antithrombotic efficacy.
