인자분석을 이용한 광주지역 미세먼지(PM₁₀)의 특성 연구

이세행 ( Se-haeng Lee ),서광엽 ( Gwang-yeop Seo ),윤상훈 ( Sang-hoon Yoon ),양윤철 ( Yoon-cheol Yang ),김선정 ( Sun-jung Kim ),조영관 ( Young-gwan Cho ),배석진 ( Seok-jin Bae ) 한국환경과학회 2018 한국환경과학회지 Vol.27 No.4

The objective of this study was to estimate air quality trends in the study area by surveying monthly and seasonal concentration trends. To do this, the mass concentration of PM10 samples and the metals, ions, and total carbon in the PM10 were analyzed. The mean concentration of PM10 was 33.9 ㎍/㎥. The composition of PM₁₀ was 39.2% ionic species, 5.1% metallic species, and 26.6% carbonic species (EC and OC). Ionic species, especially sulfate, ammonium, and nitrate, were the most abundant in the PM10 and had a high correlation coefficient with PM10. Seasonal variation of PM10 showed a similar pattern to those of ionic and metallic species. with high concentration during the winter and spring seasons. PM10 showed high correlation with the ionic species NO₃ ^- and NH₄ ⁺. In addition, NH₄ ⁺ was highly correlated with SO₄ ^2-and NO₃ ^-. We obtained four factors through factor analysis and determined the pollution sources using the United States Environmental Protection Agency(U.S. EPA) pollution profile. The first factor accounted for 51.1% of PM₁₀ from complex sources, that is, soil, motor vehicles, and secondary particles: the second factor indicated marine sources; the third factor, industry-related sources; and the last factor, heating-related sources. However, the pollution profile used in this study may be somewhat different from the actual situation in Korea because it was from US EPA. Therefore, to more accurately estimate the pollutants present, it is necessary to create a pollution profile for Korea.

Water-Soluble Ionic Characteristics of Aerosols in the Marine Boundary Layer over the Yellow Sea during the KORUS-AQ Campaign

차주완,신범철,고희정,임윤규,류상범 한국기상학회 2020 Asia-Pacific Journal of Atmospheric Sciences Vol.56 No.3

Major compositions of water-soluble ionic species in particulate matter less than 10 and 2.5 μm in diameter (PM10 and PM2.5, respectively) over the Yellow Sea were collected during the Korea–United States Air Quality (KORUS-AQ) campaign in 2016 onboard the research vessel Gisang 1. The secondary ionic species (NH4 +, nss-SO4 2−, and NO3 −) in PM10 and PM2.5 accounted for 84% and 89% of the total analyzed species. NH4 + was strongly correlated with non-sea salt (nss) SO4 2− (nss-SO4 2−) in PM10 and PM2.5; NO3 − was closely correlated with Na+, Mg2+, and nss-Ca2+ in PM10 and NH4 + in PM2.5. High mass concentrations of methane sulfonic acid (MSA, CH3SO3 −), the main source of natural sulfates over the Yellow Sea, were observed. The concentrations of MSAwere found to show an increasing trend over the Yellow Sea in recent years. Biogenic sulfur contributions to the total nss-SO4 2− (MSA/nss-SO4 2− ratio) over the Yellow Sea ranged from 1.4% to 9.2% inPM10 and from 0.68%to 9.5% inPM2.5 during the cruise. Thus, biogenic nss-SO4 2− must be included, especially in the spring and early summer seasons, when biological activities are elevated in Northeast Asia. We classified the high aerosol mass concentration cases such as Asian dust and haze cases. In Asian dust cases, the ratio of NO3 − to nss-SO4 2− in the aerosols showed that mobile (stationary) sources mainly affected PM10 (PM2.5). The major chemical species for Asian dust cases over the Yellow sea were CaCO3, Ca(NO3)2, Mg(NO3)2, Na(NO3)2, and sea salt. In haze cases over the Yellow sea, the contributions from stationary sources are high and the major species were (NH4)2SO4 and NH4NO3 in PM10 and PM2.5, respectively.

인자분석을 이용한 광주지역 초미세먼지(PM_2.5)의 특성 연구

이세행 ( Se-haeng Lee ),이경석 ( Kyung-seog Lee ),윤상훈 ( Sang-hoon Yoon ),양윤철 ( Yoon-cheol Yang ),박지영 ( Ji-young-park ),배석진 ( Seok-jin Bae ),이대행 ( Dae-haeng Lee ) 한국환경과학회 2019 한국환경과학회지 Vol.28 No.4

The objective of this study was to estimate the trends of air quality in the study area by analyzing monthly and seasonal concentration trends obtained from sampled data. To this aim, the mass concentrations of PM_2.5 in the air were analyzed, as well as those of metals, ions, and total carbon within the PM_2.5. The mean concentration of PM_2.5 was 22.7 ㎍/㎥. The mass composition of PM_2.5 was as follows: 31.1% of ionic species, 2.2% of metallic species, and 26.7% of carbonic species (EC and OC). Ionic species, especially sulfate, ammonium, and nitrate, were the most abundant in the PM_2.5 and exhibited a high correlation coefficient with the mass concentration of PM_2.5. Seasonal variations of PM_2.5 showed a similar pattern to those of ionic and metallic species, with high concentrations during winter and spring. PM2.5 also had a high correlation with the ionic species NO₃^- and NH₄⁺. In addition, NH⁴⁺ was highly correlated with NO₃^-. Through factor analysis, we identified four controlling factors, and determined the pollution sources using the United States Environmental Protection Agency(U.S. EPA) pollution profile. The first factor, accounting for 19.1% of PM_2.5 was attributed to motor vehicles and heating-related sources: the second factor indicated industry-related sources and secondary particles, and the other factors indicated soil, industry-related and marine sources. However, the pollution profile used in this study may be somewhat different from the actual situation in Korea, since it was obtained from US EPA. Therefore, to more accurately estimate the pollutants present in the air, a pollution profile for Korea should be produced.

Solvation structure of phosphonium ionic liquid/CH3SCN mixture as electrolytes for Li-ion batteries: Infrared pump-probe spectroscopic studies

Prabhat Kumar Sahu,Jungyu Kim,Kwanghee Park,Eunchan Kim,Saptarsi Mondal,Kyungwon Kwak,Minhaeng Cho 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.2

Lithium-ion battery (LIB) electrolytes based on room-temperature ionic liquids (RTIL) are promising as safe and sustainable LIB electrolytes. However, there are no reports on the solvation structure and dynamics of RTIL due to the existence of various solvation species in RTIL. Here, we investigated the solvation structure and dynamics of binary mixtures of the phosphonium ionic liquid, tributyl(2-methoxyethyl)phosphonium bis(trifluoromethanesulfonyl)imide (P444102TFSI), and methylthiocyanate (CH3SCN), with ultrafast mid-IR Spectroscopy. The changes of vibrational and rotational dynamics of CH3SCN∙∙∙Li+ complex and free CH3SCN with an increase in CH3SCN concentration suggest the presence of at least four solvation species, providing superior resolving power for various solvation species existing in complex LIB electrolytes. Our experimental results show that the environment of free CH3SCN and CH3SCN∙∙∙Li+ complex changes drastically with change in CH3SCN mole fraction and Li salt concentration in the mixture. We expect that this can affect the Li-ion transport mechanism in the IL-based electrolytes.

Charge transport in graphene oxide

Chang, Dong Wook,Baek, Jong-Beom Elsevier 2017 Nano today Vol.17 No.-

<P><B>Abstract</B></P> <P>The transport of ionic species in nano-fluidic channels has recently attracted tremendous interest in various research areas. This is because extraordinary nanoscale transport phenomena have been achieved in these materials, including ultrafast and highly selective ion movement. A variety of organic and inorganic materials have been employed to construct nano-channels or nano-pores with controlled sizes and dimensions. In particular, because of its unique two-dimensional planar architecture, as well as the possession of numerous oxygenated functionalities, GO has emerged as a promising building block for high-performance nano-fluidic ion channels. The simple exfoliation-reconstruction approach can readily assemble individual GO sheets into a free-standing, layered, film-like structure. In addition to its utilization as a versatile solid support for nano-fluidic ion transport, GO can play different but positive roles as a filler in composite electrolytes, as a mixed proton/electron conductor, and as a selective ion permeation membrane. Herein, we summarize the recent advances in the transport of ionic species within GO-based electrolytes. Moreover, the perspectives and current challenges of this promising field are discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanoscale transport phenomena have been summarized. </LI> <LI> Graphene oxide (GO) has emerged as high-performance nano-fluidic ion channels. </LI> <LI> An exfoliation-reconstruction process is utilized as a versatile method for GO electrolytes. </LI> <LI> GO can play positive roles as a mixed proton/electron conductor. </LI> <LI> In this review, the recent advances and perspectives in GO-based electrolytes are discussed. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Box-Model Simulation of the Formation of Inorganic Ionic Particulate Species and Their Air Quality Implications in Republic of Korea

박성훈,이해주,김동완,여민승,김유신,정창훈,조석주,박지훈,신혜정 한국대기환경학회 2022 Asian Journal of Atmospheric Environment (AJAE) Vol.16 No.4

The Observation-Constrained Atmospheric BOX model (OCABOX) was used to analyze the formation of secondary inorganic PM species in the Seoul Metropolitan Area (SMA), South Korea. The measurement data of the ionic components of PM2.5 and their gaseous precursors made at the Olympic Park ground site (37.53°N, 127.12°E) during the Korea-United States Air Quality field campaign were used to run OCABOX in observation-based mode and compare the simulation results. The use of the HNO3 concentrations measured at a marine background site as the boundary conditions appeared to increase the accuracy of the model prediction of HNO3 and particulate NO3 - concentrations. For the primary precursors emitted considerably throughout the SMA, such as NOx and NH3, using the data measured inside the SMA as the boundary conditions could lead to more accurate predictions. OCABOX was shown to be a reliable tool to analyze the formation of secondary inorganic aerosol in the SMA if used with appropriate regional background concentrations and observation-based constraints

태안과 강릉지역 여름철 PM₁₀의 수용성 성분 특성

박승식,고재민,정창훈,Park, Seung-Shik,Ko, Jae-Min,Chung, Chang-Hoon 한국대기환경학회 2011 한국대기환경학회지 Vol.27 No.3

[ $PM_{10}$ ]measurements were made at two coastal sites, i.e., Taean and Gangneung, for summer to examine the characterization of water-soluble organic carbon (WSOC) and inorganic ionic species, and to investigate their difference between the sites. The fractions of three major inorganic water-soluble components ($NO_3^-$, $SO_4^{2-}$, and $NH_4^+$) at Taean and Gangneung sites were 30.6% (16.2~62.0%) and 25.6% (13.0~52.5%) of the $PM_{10}$, respectively. $SO_4^{2-}$ is the most dominant species of water-soluble ions at both sites, accounting for up to 20.5% (9.1~44.9%) and 16.3% (5.5~34.2%) of their respective PM10 mass concentrations. Using the paired T-test, $PM_{10}$ (p<0.01), $NO_3^-$ (p<0.05), $SO_4^{2-}$ (p<0.01), $NH_4^+$ (p<0.001), and WSOC (p<0.05) concentrations exhibited strong fluctuations on a daily basis between Taean and Gangneung sites. Relationship between the concentrations of $SO_x$ ($SO_4^{2-}+SO_2$) and CO indicates that the slopes of $SO_x$ /CO were 0.007 and 0.019 in the Taean and Gangneung sites, respectively. The smaller $SO_x$/CO slope in the Taean site could be related to the aged air with wet scavenging of $SO_x$ during transport. The correlation between the concentrations of CO and WSOC suggests that WSOC observed in the Gangneung ($R^2$=0.82) be transported from combustion-related sources, while the WSOC at the Taean site could be formed through atmospheric processing of primary volatile organic species during transport.

태안과 강릉지역 여름철 PM_(10)의 수용성 성분 특성

박승식,고재민,정창훈 한국대기환경학회 2011 한국대기환경학회지 Vol.27 No.3

PM10 measurements were made at two coastal sites, i.e., Taean and Gangneung, for summer to examine the characterization of water-soluble organic carbon (WSOC) and inorganic ionic species, and to investigate their difference between the sites. The fractions of three major inorganic water-soluble components (NO3-, SO42-, and NH4+) at Taean and Gangneung sites were 30.6% (16.2~62.0%) and 25.6% (13.0~52.5%) of the PM10, respectively. SO42-is the most dominant species of water-soluble ions at both sites, accounting for up to 20.5% (9.1~44.9%) and 16.3%(5.5~34.2%) of their respective PM10 mass concentrations. Using the paired T-test, PM10 (p⁄0.01), NO3- (p⁄0.05),SO42- (p⁄0.01), NH4+ (p⁄0.001), and WSOC (p⁄0.05) concentrations exhibited strong fluctuations on a daily basis between Taean and Gangneung sites. Relationship between the concentrations of SOx (SO42-+SO2) and CO indicates that the slopes of SOx/CO were 0.007 and 0.019 in the Taean and Gangneung sites, respectively. The smaller SOx/CO slope in the Taean site could be related to the aged air with wet scavenging of SOx during transport. The correlation between the concentrations of CO and WSOC suggests that WSOC observed in the Gangneung (R2=0.82) be transported from combustion-related sources, while the WSOC at the Taean site could be formed through atmospheric processing of primary volatile organic species during transport.

2017년 제주시 대기 중 PM2.5의 화학적 조성과 오염원 추정

김수미,김길성,현성수,김정하,김명찬,김봉진,이기호 한국환경분석학회 2018 환경분석과 독성보건 Vol.21 No.2

In this study, to characterize chemical compositions and identify the sources of PM2.5 in the urban area of Jeju, Korea, PM2.5-bound concentrations of 8 ionic species and 12 elements were measured from samples collected at the downtown area from January to December 2017. Positive matrix factorization (PMF) was applied to these PM2.5 data-sets to identify the diverse sources in Jeju City. The average PM2.5 mass concentration for the study period was 18.31±9.72 µg/m3. The contributions of water-soluble ionic species, elements and unknown components to PM2.5 mass were 55.8%, 2.1%, and 42.0%, respectively. PMF analysis showed that a total of six source types were identified to be important. These sources are the industry related source, secondary sulfate and oil combustion, soil, biomass burning and vehicles, secondary nitrate, and sea salt.

광 산란 기반 초미세먼지 측정기의 현장 성능평가

박승식,김윤주 한국환경분석학회 2016 환경분석과 독성보건 Vol.19 No.1

Real-time particle monitors are essential for accurately managing the air quality for fine particles and estimating exposure to the fine particles. However, many such monitors tend to be prohibitively expensive. A company (called as “A” hereafter) has recently developed a low-cost, real-time particle monitor, which is based on light scattering technique, to measure mass concentration of the fine particles in the air. In this study the “A” light scattering fine particle monitor was tested to provide reliability of the monitor both in ambient and indoor environments by comparing with filter-based (“gravimetric”) and another light scattering (GRIMM) methods. 24- hr integrated PM2.5 samples were collected at the ambient and indoor sites, and used to determine their mass and ionic species concentrations. Also black carbon (BC) concentration was determined using an Aethalometer. A measurement error of the monitor, which is defined as [(gravimetric method - “A” dust monitor)/gravimetric method × 100%], was examined with variations of BC and total secondary ionic species (SIC = NO3 -+SO4 2- +NH4 +) concentrations. In ambient environment, 24-hr average PM2.5 from the “A” light scattering dust monitor was approximately 13% higher than that from the gravimetric method with correlation coefficient (R2=0.92). Similar to the results from ambient measurements, the 24-hr average PM2.5 from the “A” dust monitor in an indoor environment of a building was strongly correlated with that from the gravimetric method (R2=0.96) with approximately 12% higher concentration in the “A” dust monitor. Also the PM2.5 mass concentration from the “A” dust monitor increased linearly (R2=0.84-0.98) with increasing the concentration of SIC which are known as light scattering components in the air. However, no clear association was found between the BC (light absorbing species) and measurement errors of the monitor, indicating no influence of BC particles to the response of the “A” light scattering dust monitor. Finally, results from this study indicates that the developed low-cost, realtime monitor using the light scattering technique could be useful for the fine particle mass determination in ambient and indoor environments. However, long-term measurements are required to better improve the accuracy and a linear relationship (“calibration factor”) of the dust monitor at a variety of sampling environments.