• Journal of Environmental Science International
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• v.27 no.7
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• pp.587-595
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• 2018

This research investigated the characteristics of NO and $NO_2$ concentration at roadside (Choryangdong) and residential (Sujeongdong) locations in Busan. The NO concentration at roadside and residential were 34.7 and 8.0 ppb, respectively, and $NO_2$ at roadside and residential were 31.6 and $18.0ppb\;{\mu}g/m^3$, respectively. The NO concentration was the highest in winter at roadside at 37.1 ppb, followed by 35.0 ppb and 34.0 ppb in summer and fall, respectively. $NO_2$ concentration was the highest in spring at roadside at 39.6 ppb, followed by 30.4 ppb and 28.3 ppb in fall and winter, respectively. Number of exceedances per year of 1 hr limit value (0.10 ppm) for $NO_2$ at roadside and residential were 3,585 and 3 hours, respectively. Number of exceedances per year of 24 hr limit value (0.06 ppm) for $NO_2$ at roadside and residential were 32 and 1 days, respectively. Number of exceedances per year of 1 hr limit value (0.1 ppm) for $O_3$ at roadside and residential were 1 and 14 days, respectively. These results indicated that understanding the relationship between roadside and residential could provide insight into establishing a strategy to control urban air quality.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.E2
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• pp.69-77
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• 2002

The nationwide NO$_2$monitoring program has been carried out using the passive sampler in Korea since 1993. During the sixteenth periods of measurement, total 26,474 sites of data were collected through eight years. In this paper, the roadside NO$_2$concentration of six major cities were analyzed. As results, the most frequent NO$_2$concentration of Seoul, Incheon, and Daegu ranged from 40 to 60 ppb, and that of Pusan, Kwanju, and Daejeon was from 20 to 40 ppd. Despite that the automobile number of Incheon was less than that of Daegu and Pusan, the exceedence rate of Korean national ambient air quality standard and ninetieth percentile concentration of Incheon were almost the same level as Seoul. In addition, the mean and standard deviation of roadside NO$_2$concentration of Seoul and Incheon was also appeared to be higher than that of other cities. These results indicates that NO$_2$concentration on roadside was affected by the traffic volumes and the traffic flow conditions.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.E
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• pp.9-16
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• 1999

This study has been focused on NO conversion for metal-incorporated silicates(Fe-silicate, Mn-silicate, and Fe-Mn-bimetallosilicate) with a similar MFI type. Used metallosilicates were prepared by the rapid crystallization method. Their catalytic performance for the conversion of NO under excess O2(10%) condition with the addition of hydrocarbon of low concentration(1,100ppm n-C8H18) were investigated. As a result, the NO conversion on the Fe-Mn-bimetallosilicate was enhanced compared with on the Fe- or Mn-silicates. Furthermore, the performances for NO concentration on Fe-Mn-bimetallosilicate more increased with an increased in n-C8H18 concentration, a decrease in NO concentration, and an increase in O2 concentration.

• Journal of environmental and Sanitary engineering
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• v.12 no.3
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• pp.51-59
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• 1997

In this study, we researched the concentration of nitrogen dioxide($NO_{2}$) and sulfur dioxide($SO_{2}$) of indoor(waiting room) and outdoor(place of getting on the bus) at the bus terminals (Kang-Nam, Dong-Seoul and Nam-Bu) in Seoul to recognize the degree of pollution by exhaust gas of the diesel engine vehicles, and examine the factor that might affect air pollution of terminals. The concentration of $NO_{2}$ and $SO_{2}$ were measured in winter and summer, and the results of the analysis are as follows : The mean concentration of $NO_{2}$ was $57.49{\pm}21.86$ ppb and the concentration of outdoor with $64.10{\pm}27.69$ ppb was significantly higher than the indoor with $50.89{\pm}10.92$ ppb (p<0.05), and the highest with $73.54{\pm}25.54$ ppb at Kang-Nam terminal (p<0.01). The mean concentration of $NO_{2}$ was $62.80{\pm}24.74$ ppb in winter and $52.19{\pm}17.50$ ppb in summer, and had a not statistical difference. The mean concentration of $SO_{2}$ was $31.71{\pm}8.73$ ppb and the concentration of outdoor with $31.04{\pm}8.89$ ppb was similar to the indoor $32.29{\pm}8.70$ ppb, and the highest with $32.57{\pm}9.01$ ppb at Dong-Seoul terminal (p<0.05). The mean concentration of $SO_{2}$ in winter with $39.67{\pm}4.10$ ppb was significantly higher than in summer with $23.76{\pm}2.61$ ppb (p<0.01). The concentration of outdoor $NO_{2}$ at Kang-Nam terminal was 104, 84 ppb in winter and 81.20 ppb in summer, and had a statistical difference compared with the concentration of indoor $NO_{2}$ at Dong-Seoul and Nam-Bu terminals. The concentration of indoor $NO_{2}$ and $SO_{2}$ were higher than that of outdoor at Kang-Nam and Dong-Seoul terminals, but on the contrary, lower than that of outdoor at Nam-Bu terminal. The concentration of $NO_{2}$ and $SO_{2}$ at Nam-Bu terminal were lower than those at Kang-Nam and Dong-Seoul terminals. While the concentration of $SO_{2}$ show the large difference between winter and summer, that of $NO_{2}$ dose not.

• Transactions of the Korean Society of Mechanical Engineers
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• v.1 no.4
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• pp.171-181
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• 1977

This paper is aiming at calculating NOx concentration, which is one of the harmhul components of emission from the gasoline engine, formed in the combustor through the presess of combustion. Instantaneous temperature and concentration of each components for each division can be determined by the solution of simulatneous equation of reaction equation and equation of energy conservation, inputting the estimated temperature with a considerably wide rage of temperature. After determining instantaneous temperature and instantanous concentration of each components, the nonequilibrium calculation is performed based on the reaction kinetics in order to determine NOx concentration. To summarize the result abtained from the above method ;through the passage of NO concentration, NO concentration is the highest in the first division and it is gradually decreasing through the following divisions In the final division, NO concentation is the lowest.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.319-325
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• 2002

This experiment was carried out to investigate the effects of heavy metals (copper, cadmium, lead and chrome) on the growth of plant and seed germination of Arabidopsis thaliana treated with various concentrations of heavy metals. Cadmium and chrome among the 4 heavy metals had no effect on the growth of stem even in the concentration fifty times higher than the official standard concentration of pollutant exhaust notified by the Ministry of Environment. The official standard concentration of cadmium, however, stimulated the growth of stem in general, increasing leaf size and surface area, although it had no effect on the length of stem. But the growth of stem was decreased about 18% in the official standard concentration of pollutant exhaust of lead and copper. There was no growth of root in the concentration of lead and copper ten times higher than the official standard concentration. Cadmium and chrome had no effect on the seed germination, but lead and copper decreased the rate of seed germination. Seeds were not germinated in the concentration of copper ten times higher than the official standard concentration and in the concentration of lead fifty times higher than the official standard concentration. From this research three peculiar results were obtained. Chrome in the soil did not have much effect on the plant growth and seed germination of Arabidopsis thaliana. Cadmium stimulated the stem growth in an optimum concentration. But lead and copper reduced the plant growth and seed germination even in a small concentration, especially copper had the worse effect.

• Journal of the Korean Society of Safety
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• v.10 no.2
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• pp.105-112
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• 1995

The concentrations of $NO_2$ were measured to estimate a new developed long term exposure $NO_2$ sampler at Pusan City considering the meteorological factors from May to July, in 1994. The monthly mean concentration of $NO_2$ was 15.9 PPb and 36.2 ${\mu}\ell$/day $NO_2$ and their high values were shown in the downtown of Pusan City which show potential pollution due to the increase of traffic activities and micrometeorological factors In and around the City. As a result of statistical correlation between $NO_2$ concentration by new sampling method and $NO_2$ concentration by the handy air sampler and chemiluminescent nitrogen oxides analyzer, 1994, correlation coefficients were high(r=0.93) and showed more than 0.88 value in the high concentration data set, which was arbitrarily divided into 30${\mu}\ell$ $NO_2$ concentration in an attempt to further investigate these relationships. Therefore, use of new developed long term exposure $NO_2$ sampler is good for $NO_2$ measurement and valuable for estimation of air quality in the urban and Industrial area.

• Carbon letters
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• v.1 no.1
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• pp.17-21
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• 2000

Catalytic reduction and oxidation of NO over polyacrylonitrile based activated carbon fibers (PAN-ACF) under various conditions were carried out to develop removal process of NO from the flue gas. The effect of temperature, oxygen concentration and the moisture content for the reduction of NO with ammonia as a reducing agent was investigated. The reduction of NO increased with the oxygen concentration, but decreased with the increased temperature. The moisture content in the flue gas affects the reduction of NO as the inhibition of the adsorption of the other components and the reaction on the surface of ACE For the oxidation of NO to $NO_2$ over PAN-ACF without using a reducing gas, it showed the temperature and the oxygen concentration of the flue gas are the important factors for the NO conversion in which the conversion increased with oxygen concentration and decreased with the temperature increase and might be the alternative option for the selective catalytic reduction process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.922-926
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• 2002

In this paper, in order to investigate the catalytic effect of the sludge exhausted from waterworks as heating temperature for NOx removal, we measure NO, $NO_2$ concentration as increasing temperature of sludge pellets and applying high voltage to sludge pellets in a quartz-glass reactor at the same time. NO initial concentration is 100ppm balanced with air gas in a mixing chamber. The gas flow is 5[l/min] and the heating temperature of sludge pellets in a quartz-glass reactor is adjusted from $200[^{\circ}C]$ $400[^{\circ}C]$ to investigate the effect of sludge pellets for removal NOx$(NO+NO_2)$ as increasing temperature. $BaTiO_3$ pellets is filled in a packed-bed reactor for corona discharge to measure how much NOx$(NO+NO_2)$ is removed after generating $NO_2$ from the packed-bed reactor. AC[60Hz] voltage is supplied to the reactor for discharge. In the result, $NO_2$ concentration is decreased by sludge pellets without heating temperature for sludge pellets in case of sludge pellets done heat treatment, however NO concentration is almost the same to be compared NO initial concentration. As increasing heating temperature for sludge pellets, $NO_2$ adsorbed on the sludge surface done heat treatment is converted to NO by the thermal energy, so NO concentration is extremely increased by reduction decomposition of $NO_2$. Finally, We think the sludge is possible to use for reduction catalysts, however we need to study more about the possibility and endurance of sludge as catalysts for NOx removal.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.825-829
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• 2012

In this study, we investigated NO oxidation characteristic that depends on available chlorine concentration and temperature of seawater which is treated by un-divided electrolysis. Reactant gas passed through bubbling reactors which is filled with electrolyzed water and then NO concentration change was analyzed. In the closed-loop electrolysis system, concentration of available chlorine increased with electrolysis time. The higher oxidation rate of NO to $NO_2$ was obtained with the higher concentration of available chlorine. Oxidation of NO was fast when temperature of electrolyzed water was high, in the case of same concentration of available chlorine.