• 한국대기환경학회지
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• 제31권4호
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• pp.330-344
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• 2015

Semi-continuous measurements of $PM_{2.5}$ mass, organic and elemental carbon were made for the period of January to October 2014, at six national air monitoring stations in Korea. OC and EC concentrations showed a clear seasonal variation with the highest in winter (January) and the lowest in summer (August). In winter, the high carbonaceous concentrations were likely influenced by increased fuel combustion from residential heating. OC and EC concentrations varied by monitoring stations with 5.9 and $1.7{\mu}g/m^3$ in Joongbu area, 4.2 and $1.2{\mu}g/m^3$ in Honam area, 4.0 and $1.3{\mu}g/m^3$ in Yeongnam area, 3.7 and $1.6{\mu}g/m^3$ in Seoul Metropolitan area, 3.0 and $0.8{\mu}g/m^3$ in Jeju Island, 2.9 and $0.7{\mu}g/m^3$ in Baengnyeong Island respectively. The concentrations of OC and EC comprised 9.6~ 15.5% and 2.4~ 4.7% of $PM_{2.5}$. Urban Joongbu area located adjacent to the intersection of several main roads showed the highest carbon concentration among six national air monitoring station. On the other hand, background Baengnyeong Island showed the lowest carbon concentration and the highest OC/EC ratio (4.5). During the haze episode, OC and EC were enhanced with increase in $PM_{2.5}$ about 1.3~ 3 and 1.3~ 4.0 times respectively. The concentrations of OC, EC in the Asian dust case are about 1~ 2.4 times greater than in the nondust case. The origins of air mass pathways arriving at Seoul, using the backward trajectory analysis, can be mostly classified into 6 groups (Sector I Northern Korea including the sea of Okhotsk, Sector II Northern China including Mongolia, Sector III Southern China, Sector IV South Pacific area, Sector V Japan, Sector VI Southern Korea area). When an air mass originating from northern China and Mongolia, the OC concentrations were the most elevated, with a higher OC/EC ratio (2.4~ 3.3), and accounting for 17% of $PM_{2.5}$ mass on average.

• 한국대기환경학회지
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• 제33권6호
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• pp.616-625
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• 2017

Measurements using five real-time particle samplers were compared to measurements using three NRM (National Reference Method system) filter-based samplers(Gravimetric method) at Incheon, Korea, between May and August, 2014. The purpose of this study was to suggest the quality assurance/quality control (QA/QC) method of each instrument for use in a real-time continuous particle sampler to measure the mass of airborne particles with an aerodynamic diameter less than $2.5{\mu}m$ ($PM_{2.5}$). Five real-time particle samplers of BAM1020, FH62C_14, TEOM, PM-711 and SPM-613 were evaluated by comparing its measured 23 hr average $PM_{2.5}$ concentrations with those measured with NRM filter-based samplers simultaneously. The parameters(e.g. Inlet heating condition, Slope factor, Film response, Intercept, Background, Span value) of the real-time samplers were optimized respectively by conducting test performance evaluation during 7 days in field sampling. For example, inlet heating temperature of TEOM sampler controls $35{\sim}40^{\circ}C$ to minimize the fluctuation of the real-time measurement data and background value of BAM1020 is the key factor affecting the accuracy of $PM_{2.5}$ mass concentration. We classified the $PM_{2.5}$ concentration according to relative humidity (80%) to identify water absorbed in aerosols by measuring the ${\beta}$-ray samplers(BAM1020, FH62C_14) and TEOM. ${\beta}$-ray samplers were not strongly affected by relative humidity that the difference of the average $PM_{2.5}$ concentration was about 5%. On the other hand, The TEOM sampler overestimated $PM_{2.5}$ mass concentration about 15% at low relative humidity (<80%).

• 한국대기환경학회지
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• 제28권3호
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• pp.282-293
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• 2012

This study aimed to show the chemical characteristics of $PM_{10}$ and $PM_{2.5}$ during Asian dust (AD) events and high PM episodes observed in Seoul. Time-resolved chemical composition of $PM_{10}$ or $PM_{2.5}$ was monitored in 1 hour interval using ambient ion monitor, semi-continuous carbon monitor, and on-line XRF spectrometer at Seoul intensive monitoring site in 2009. Considering that AD events were classified into three different cases according to the source area and pathway, the concentrations of ammonium-sulfate and trace metal components were relatively high when the AD were occurred in Gobi and inner-mongolia and transported across the Bohai bay. In addition, the influence of alkaline dust, which carried from saline land located in the northeastern China, was observed when the AD was originated from Gobi, inner-mongolia, and Manchuria. Except AD events, the high PM episodes observed in Seoul were impacted by various anthropogenic sources such as biomass burning, motor vehicle, oil combustion and road dust.

• Asian Journal of Atmospheric Environment
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• 제11권4호
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• pp.235-253
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• 2017

This study was conducted for analyzing the contribution factors on ozone concentrations and its long term trends in each major city and province in Korea through several statistical methods such as simple linear regression, generalized linear model, KZ-filer, correlation matrix, Kringing method, and cluster analysis. The overall ozone levels in South Korea have been consistently increasing over the past 10 years. The ozone concentrations in Seoul, the biggest city in Korea, are the lowest in all areas with the highest increasing ratio for $95^{th}%$ ozone. It is thought that the active photochemical reaction could affect the higher ozone concentration increase. On the other hand, the ozone concentrations in Jeju are the highest in Korea with the highest increasing ratio for $5^{th}%$, $33^{th}%$, and $50^{th}%$ ozone. It is also thought that the weak $NO_x$ titration could be the reason of higher ozone concentrations in Jeju. In case of Jeju, transport related factors is the major factor affecting the ozone trend. Thus, it is assumed that the variation of ozone trend of Asian region affecting the ozone trend in Jeju, where domestic ozone photochemical reaction is less active than urban area. It is thought that the photochemical reaction plays the role of increasing of ozone concentrations in the urban area, even though the LRT affected on the increase of ozone concentrations in non-urban area.

• 도시과학
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• 제6권2호
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• pp.1-13
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• 2017

The air quality management in regional viewpoint was investigated for the improvement of national air pollution with various standard air pollutants. The focal region in this research is north-eastern region in asia where the many developing industries are located in neighboring countries. The major concerns were the trends of air quality in recent years and the state of environmental technologies and policies of air quality in each countries. The regional air quality management for the improvement of air pollution and the effective programs were suggested for the effective air quality management.

• 대한임베디드공학회논문지
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• 제11권3호
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• pp.143-151
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• 2016

In this paper, a real-time air quality monitoring system based on wireless network is designed and implemented for industrial park or multiuse facilities. The existing gas detector is high price and hard to apply the remote monitoring system. On the other hand, demand for air quality monitoring is increasing because of industrial gas accident, air pollution, and so on. In Korea, indoor air regulation was established by law. According to indoor air regulation, CO2, CO, and NO2 are important gases as the air quality standard. So we study the gas detector for indoor air quality and the wireless network system. The wireless network consist of sensor network and WCDMA to apply various place. To verify the performance of the implemented gas detector, the gas measurement experiment is performed in laboratory environment by using the realized gas detecting wireless sensor node. And we evaluate the experiment results.

• 한국대기환경학회지
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• 제31권4호
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• pp.319-329
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• 2015

The characteristics of aerosol light extinction were investigated by comparing measured and calculated extinction coefficient to understand the contribution of air pollutants on visibility impairment for data during 4 months (Jan~ April), 2014. The integrated nephelometer and aethalometer system were installed to measure the scattering and absorption coefficients of aerosol as well as BAM 1020, MARGA, semi-continuous OCEC analyzer, and online-XRF to calculate the extinction coefficient. The IMPROVE_2005 equation was used to determine the contributions of different chemical components on visibility impairment in $PM_{2.5}$ and $PM_{10}$ due to highest correlation with measured data. Sulfate, nitrate, and organic mass by carbon (OMC) of fine aerosol were the major contributors affecting on visibility impairment. Total contributions to light extinction were calculated as $631.0Mm^{-1}$ for the worst-case and $64.4Mm^{-1}$ for the best-case. The concentrations of aerosol component for the worst-case were 38.4 times and 45.5 times larger than those of the best-case for $(NH_4)_2SO_4$ and $NH_4NO_3$, respectively. At lower visibility condition, in which extinction coefficient was higher than $400Mm^{-1}$, extinction coefficient varied according to the relative humidity variation regardless of $PM_{2.5}$.

• Asian Journal of Atmospheric Environment
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• 제5권4호
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• pp.278-291
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• 2011

Korea has experienced dramatic development and has become highly industrialized and urbanized during the past 40 years, which has resulted in rapid economic growth. Due to the industrialization and urbanization, however, air pollutant emission sources have increased substantially. Rapid increases in emission sources have caused Korea to suffer from serious air pollution. An air pollutant emissions inventory is one set of essential data to help policymakers understand the current status of air pollution levels, to establish air pollution control policies and to analyze the impacts of implementation of policies, as well as for air quality studies. To accurately and realistically estimate administrative district level air pollutant emissions of Korea, we developed a Korean Emissions Inventory System named the Clean Air Policy Support System (CAPSS). In CAPSS, emissions sources are classified into four levels. Emission factors for each classification category are collected from various domestic and international research reports, and the CAPSS utilizes various national, regional and local level statistical data, compiled by approximately 150 Korean organizations. In this paper, we introduced for the first time, a Korean national emissions inventory system and release Korea's official 2007 air pollutant emissions for five regulated air pollutants.

• 한국대기환경학회지
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• 제30권5호
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• pp.434-448
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• 2014

The aerosol characteristics between haze episode and Asian dust event were identified in January and March, 2013 in Gwang-ju of Korea to investigate the metal elements, ionic concentrations and carbonaceous particles of $PM_{2.5}$ and $PM_{10}$. In the haze episode, the concentrations were increased 1~3.2 times of ionic species and 1.6~2.7 of metal elements. Especially, the concentration of $NO{_3}{^-}$, $SO{_4}{^2-}$ and $NH{_4}{^+}$ consists of 50 percent in ionic species during haze episode that was higher than Asian dust event. This suggests that secondary aerosols from anthropogenic air pollution were mainly contributed by haze episode. During the Asian dust event, increase of metal concentrations was higher than haze episode because of remarkable increase of Ti, K and Fe originated from soil. The concentrations of carbonaceous particles were increased 2.5 times during haze episode, and 2.4 times of OC and 2.1 times of EC during Asian dust event in $PM_{2.5}$. However, these aerosol mass concentration does not affect the OC/EC ratio. The average equivalence ratios of cations/anions in $PM_{2.5}$ were 0.99 in haze episodes and 0.94 during non-event day. The neutralization factor of $NH_3$ was higher than that of $CaCO_3$. Futhermore, $NH{_4}{^+}$ aerosol was aged due to atmospheric stagnation that might be affected by the haze episode.

• 한국대기환경학회지
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• 제31권2호
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• pp.157-163
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• 2015

To establish National Reference Method (NRM) for $PM_{2.5}$, operational performance of 5 different commercial gravimetric-based $PM_{2.5}$ measuring instruments was assessed at Bulkwang monitoring station from January 23, 2014 to February 28, 2014. First, physical properties, design, and functional performance of the instruments were assessed. Evaluation was carried out to determine whether operating method for the instruments and levels of QA/QC activities meet the data quality objectives (DQOs). To verify whether DQOs were satisfied, reproducibility of QA/QC procedures, accuracy, relative sensitivity, limit of detection, margin of error, and coefficient of determination of the instruments were also evaluated. Results of flow rate measurement of 15 candidate instruments indicated that all the instruments met performance criteria with accuracy deviation of 4.0% and reproducibility of 0.6%. Comparison of final $PM_{2.5}$ mass concentrations showed that the coefficient of determination ($R^2$) values were greater than or equal to 0.9995, and concentration gradient ranged from 0.97 to 1.03. All the instruments satisfied criteria for NRM with the estimated precision of 1.47~2.60%, accuracy of -1.90~3.00%, and absolute accuracy of 1.02~3.12%. This study found that one particular type of measuring instrument was proved to be excellent, with overall evaluation criteria satisfied.