• Title/Summary/Keyword: High ozone

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Air Pollution Monitoring in Taiwan: An Application of Tethersonding in Coastal Central Taiwan

  • Cheng, Wan-Li
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2005.06a
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    • pp.184-210
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    • 2005

  • The atmospheric transportation and dispersion processes of air pollutants are important issues in dealing with air pollution problems. Air pollutants originated from biological and anthropogenic activities are not only limited to the local emission sources, but could also be transported and dispersed to other regions by synoptic weather systems. Besides, the complexity of topography of central Taiwan helps accumulating air pollutants to promote high-concentration episodes. The techniques of tethersonding were applied to monitor the vertical profiles of winds, air temperatures and humidity, as well as to collect air samples, to be analyzed for pollutants ($O_3,\;NO_2$, NO and NMHC) from the ground up to 1000 m. A time period of about one week, 19 -26 October 2002, was chosen as the sampling period due to the high frequency of episode occurrence in autumn based on the past records. Associating with the analysis of weather patterns, the atmospheric characteristics over high-concentration areas can be resolved in more detail. The result of the tethersonding studies showed that weak northerly sea breeze (with thickness about 300 m) with now wind speed (about 1 to 2 m/sec) could help develop high ozone concentrations in the down-wind areas. It is also important to have a built-up aloft of precursors and ozone to develop high concentration on the previous day.

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Influence of N-P-K Nutrient Levels on Ozone Susceptibility of Tomato Plants (N-P-K 양분 수준이 토마토의 오존 감수성에 미치는 영향)

  • Ahn, Joo-Won;Ku, Ja-Hyeong
    • Korean Journal of Environmental Agriculture
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    • v.17 no.4
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    • pp.352-357
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    • 1998

  • This experiment was conducted to find out the effects of major nutrient levels(N, P, K) on ozone susceptibility of tomato plants(Lycopersicon esculentum Mill, cv. Pink Glory). Plants were grown in water culture system. A half-strength of Hoagland's nutrient solution was considered as a standard formulation($N_{100}$ $P_{100}$ $K_{100}$). The levels of major nutrients were adjusted through addition or removal of several fertilizer salts from the standard solution. Top growth was significantly decreased at the low nitrogen level or phosphorus removal condition. P- and K-contents of leaves were greatly decreased by removal of salts containing P and K from the nutrient solution. The rate of ozone injury was significantly increased when potassium was removed. However, the influence of nitrogen and phosphorus levels or high potassium level on injury occurrence did not show statistical significance compared to the standard solution. Ozone exposure resulted in reduction of chlorophyll, and increase of ethylene production, electrolyte leakage and malondialdehyde(MDA) contents. These changes were much more enhanced in plants grown at the potassium removal solution. Whereas the activity of superoxide dismutase(SOD) was low at the potassium removal treatment and this tendency remained after ozone exposure. These results indicated that potassium nutrient level in tomato plants is closely associated with the susceptibility to ozone injury.

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Response of Ozone Sensitivity in Open-Pollinated Families of Pinus densiflora Seedlings (소나무 풍매차대묘(風媒次代苗)의 가계간(家系間) 오존에 대한 민감성(敏感性) 반응(反應))

  • Lee, Jae-Cheon;Oh, Chang-Young;Han, Sim-Hee;Kim, Jang-Su
    • Journal of Korean Society of Forest Science
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    • v.94 no.3 s.160
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    • pp.191-196
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    • 2005

  • This studies were conducted to compare ozone sensitivity among half-sib families of Japanese red pine (Pinus densiflora S. et Z.). 90 families were exposed in walk-in type chambers to charcoal-filtered air and 100 ppb ozone for 8 hours daily, 5 consecutive months. We surveyed the foliar injury, Relative DRC (diameter at root collar) growth and relative dry weight after fumigation. After 5 months of exposure, foliar injury ranged from 1.9% at tolerant group to 15.2% at sensitive group. Relative DRC growth rates showed increased 12% at tolerant group, but reduced 23% at sensitive group. Total dry weight increased 17% at tolerant group, otherwise reduced by 33% at sensitive group, relative to the control. The root biomass showed more sensitive than the other part biomass. On the basis of the results of these screening studies, families Kangwon 04, 16, 26, 27 and 73 were determined to be tolerant; Kangwon 40, 52, 83, Gyeonggi 01 and Gyeongbuk 20 to be sensitive to ozone. Considerable genetic variation in ozone responses occurred, as shown by differences in sensitivities among families and among groups. These results indicate that tolerant groups of P. densiflora exhibited a high degree of resistance to ozone pollution injury.

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Evaluation of Ozone Resistance and Anti-Corrosion Performance of Water Treatment Concrete according to Types of Metal Spray Coating (수처리시설용 콘크리트의 금속용사 피막 종류에 따른 내오존성 및 전기화학적 방식 성능 평가)

  • Park, Jin-Ho;Choi, Hyun-Jun;Lee, Han-Seung;Kim, Sang-yeol;Jang, Hyun-O
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.4
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    • pp.61-68
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    • 2019

  • As the pollution of water resources deteriorates due to industrialization and urbanization, it is difficult to supply clean water through a water treatment method using chlorine. Therefore, the introduction of advanced water treatment facilities using ozone is on the increase. However, epoxy which is used as waterproofing and anticorrosives and stainless steel used in conventional waterproofing and anti-corrosive methods have deteriorated because of the strong oxidizing power of ozone, causing problems such as leaking. Moreover, it even causes the durability degradation of a concrete. Therefore, in this study, metal spraying system was used as the means of constructing a metal panel with excellent ozone resistance and chemical resistance which is an easier method than an existing construction method. Ozone resistance was evaluated in accordance with the type of metal sprayed coatings to develop a finishing method which can prevent the concrete structure of water treatment facilities from deterioration. Furthermore, electrochemical stability in actual sewage treatment plant environment was evaluated. Experimental results showed that Ti has superior ozone resistance after spraying and the electrochemical stability in the sewage treatment plant environment showed that Ti has the highest polarization resistance of $403.83k{\cdot}{\Omega}{\cdot}cm^2$, which ensures high levels of durability.

  • https://doi.org/10.11112/jksmi.2019.23.4.61 인용 PDF KSCI