항공기를 이용한 남해안 지역의 오존 공간분포 조사 (2009년, 여름철)

서석준(Seok-Jun Seo),김소영(So-Young Kim),이민도(Min-Do Lee),최진수(Jin-Soo Choi),김수연(Su-Yeon Kim),이석조(Seok-Jo Lee),김정수(Jeong-Soo Kim),이강웅(Gang-Woong Lee) 한국대기환경학회 2012 한국대기환경학회지 Vol.28 No.1

환경대기 중 저분자 PAHs 측정을 위한 흡착-열탈착-GC/MS 방법의 적용

서석준(Seok-Jun Seo),서영교(Young-Kyo Seo),황윤정(Yoon-Jung Hwang),정동희(Dong-Hee Jung),백성옥(Sung-Ok Baek) 한국대기환경학회 2014 한국대기환경학회지 Vol.30 No.4

희소금속 재활용을 위한 ITU-T 국제표준 개발현황

이미혜,최원정,서석준,김범성,Lee, Mi Hye,Choi, Won Jung,Seo, Seok-Jun,Kim, Bum Sung 한국분말야금학회 2016 한국분말재료학회지 (KPMI) Vol.23 No.4

Owing to increasing demand of rare metals present in ICT products, it is necessary to promote the rare metal recycling industry from an environmental viewpoint and to prevent climate change. Despite the fact that information for toxic substances is partly indicated, a legal basis and an international standard indicating usage of rare metals is insufficient. In order to address this issue, a newly created study group of environment and climate change at the ITU (International Telecommunication Union) is doing research to develop methodologies for recycling rare metals from ICT products in an eco-friendly way. Under this group, the Republic of Korea has established two international standards related to rare metals present in ICT products. The first is 'Release of rare metal information for ICT products (ITU-T L.1100)' and the other is 'Quantitative and qualitative analysis methods for rare metals (ITU-T L.1101)'. A new proposal for recommending the provision of rare metal information through a label by manufacturers and consumer/recycling businesses has been approved recently and is supposed to be published later in 2016. Moreover, these recommendations are also being extended to IEC, ISO and other standardization organizations and a strategy to reinforce the ability for domestic standardization is being established in accordance with industrial requirements. This will promote efficient recycling of rare metals from ICT products and will help improve the domestic supply of rare metals.

시계열 데이터에 대한 특징 추출 기반 이상 탐지

서호건(Hogeon Seo),송준영(Junyoung Song),조우진(Woojin Jo),서석준(Seok-Jun Seo) 한국비파괴검사학회 2024 한국비파괴검사학회지 Vol.44 No.1

항공관측 및 대기질 모델링을 통한 L TP 영향 산정

장임석(Lim-Seok Chang),성경희(Kyoung-Hee Sung),최진수(Jin-Su Choi),반수진(Soo-Jin Ban),안준영(Joon-Young Ahn),서석준(Seok-Jun Seo),김수연(Su-Yeon Kim) 한국환경관리학회 2010 環境管理學會誌 Vol.16 No.2

본 연구는 한반도 주변지역 장거리 이동 대기오염물질의 특성파악과 중국으로부터 이동되어 오는 장거리 이동 대기오염물질이 한반도 대기질에 미치는 영향을 평가하고 그 원인 규명을 통하여 과학적인 저감대책을 수립하는 것이 최종 목적이다. 이러한 목적을 위하여 항공기를 이용하여 서해 상공에서 대기오염물질의 측정과 집중측정 기간에 대한 상층기상 및 종관 분석을 수행하였다. 1997~2009년까지 측정기간 중 서해상에 영향을 준 기류의 48%가 Ⅱ권역의 영향이었고 기류의 이동경로 별로 뚜렷한 농도 차이를 보였다. 그 외 권역은 1.09~3.78 ppb의 범위를 보였고 Ⅱ, Ⅲ권역 사례의 7~25%, 4~15%에 불과하여 권역 Ⅱ, Ⅲ을 영향을 SO₂ 고농도 사례의 주요 원인으로 생각할 수 있다. 또한 권역별 기류에 따른 이동량을 분석한 결과, SO₂의 경우 측정기간 중 유입량은 유출량의 약 5배로 서해안이 중국으로부터 이동하는 SO₂의 직접적인 영향을 받고 있는 것으로 나타났다. To estimate the long-range transboundary air pollutants, aircraft measurements, upper and synoptic atmosphere analysis, and modeling have been performed. Flight measurement was carried out over the West Sea of Korea when westerly winds to identify the impact of air pollutants from China on air quality in Korea and to estimate the transboundary influx of air pollutants. In this year, it was found that long-range air pollutants were transported in various patterns. On April 17, a high concentration appeared in two different layers, while on October 16 a high concentration occurred in all sections due to the stagnation of the pollutants. As a result of back trajectory analysis by region, 48 percent of the total air currents affecting air quality over the West Sea during the observation periods (1997~2009) came from Region Ⅱ, with the concentrations of each transport track distinctively different. The modeling was conducted using MM5, SMOKE, and CMAQ. The impact of long-range air pollutants on local air quality was examined through emissions sensitivity analysis for the spring (Mar.~May) and Autumn (Sep.~Nov.) of 2009. In spring, about 18~65% of the total PM10 concentration was influenced by long-range transported air pollutants, while in autumn from 11 to 51% of the PM₁? concentration was affected. These results will be better estimated through the constant improvement of emission data. For the accuracy of the modeling work, a preliminary study should be done first, including improvement of emission inventories, identification of complex aerosol and photochemical reaction mechanism in the atmosphere, and establishment of contribution assessment methodology.

수도권 지역 대기 중 카보닐화합물의 시ㆍ공간적 농도 분포 특성

서영교(Young-Kyo Seo),정은희(Eun-Hui Jeong),서석준(Seok-Jun Seo),황윤정(Yun-Jeong Hwang),한진석(Jin-Seok Han),백성옥(Sung-Ok Baek) 한국대기환경학회 2008 한국대기환경학회지 Vol.24 No.2

The purpose of this study is to evaluate concentrations of carbonyl compounds during summer season in Seoul metropolitan area. The air samples were collected at 7 sites in this area from June 2001 to June 2003. The carbonyl compounds were analyzed by DNPH/HPLC method. The analytical method applied in this study showed good repeatability, linearity, and sensitivity. The most abundant carbonyl was formaldehyde (average 4.48 ppb), and followed by acetone, acetaldehyde, methyl ethyl ketone, butyraldehyde, propionaldehyde and benzaldehyde, respectively. Concentrations of carbonyl compounds in June were higher than those in August. There was not only higher solar radiation but also higher ozone concentration in June than in August. As a result of photochemical reactions, carbonyl compounds from both primary and secondary sources are likely to contribute to the formation of ozone. The contributions to photochemical ozone creation of two carbonyl compounds such as formaldehyde and acetaldehyde were estimated to be about 70%. Ratios of formaldehyde to acetaldehyde in this study ranged from 1.13 to 4.26, which are generally equivalent levels to those of other urban areas in domestic and foreign countries.

축전식 탈염 시스템을 위한 셀 구조에 관한 연구

이주영 ( Ju Young Lee ),서석준 ( Seok Jun Seo ),박정우 ( Jung Woo Park ),문승현 ( Seung Hyeon Moon ) 한국화학공학회 2010 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.48 No.6

축전식 전기탈이온(Capacitive deionization: CDI) 시스템을 실제공정에 적용하기 위하여 대용량 제작이 가능하며 높은 처리 효율을 갖는 셀 구조 연구가 필요하다. 본 연구에서는 대용량 제작을 위하여 낮은 수압으로 운전할 수 있는 병렬형 구조와 처리효율을 증가시키기 위하여 집중형 유로를 동시에 적용하여 설계하고 성능 평가하였다. 설계한 유로 구조의 유입수 흐름을 확인하기 위하여 유체역학적 모델링이 가능한 COMSOL프로그램을 사용하여 집중형 유로가 형성되는 것을 확인하였고, 염 제거 효율을 확인하기 위하여 단위 셀과 20층으로 용량 증축된 스택을 사용하여 CDI운전을 통한 제거효율을 확인하였다. 그 결과 210 cm2 면적의 단위 셀에서는 18 ml/min의 유량조건에서 1.1psi의 수압으로 70.8%의 제거효율을 보였으며, 20층으로 용량 증축된 셀에서는 유량을 20배로 늘린 360 ml/min의 유량조건에서 1.3~1.5psi의 수압으로 75.6%의 제거효율을 확인할 수 있었다. 연구된 유로 설계는 대용량 시스템을 제작하는데 있어서 적합한 병렬형 구조이며 효율적인 탈염을 할 수 있는 집중형 유로로 설계되어 실제공정에 적용할 수 있는 구조임을 확인할 수 있었다. This study presents channel design of a CDI stack to achieve high removal efficiency in a large scale by applying parallel flow structure with a concentrated stream. The flow pattern in the stack was simulated by COMSOL Multiphysics program. To prove the salt removal performance, a unit cell and 20 cell stacks were tested at a flow rate condition of 18 ml/min and 360 ml/min, respectively. The removal efficiencies of the unit cell and the 20 cell stacks were obtained as 70.8 % and 75.6 %, respectively, with 100 mg/L sodium chloride solution. During the operation of cell test, water pressures of unit cell and 20 cell pair stack maintained in the ranges of 1.1psi and 1.3~1.5psi, respectively. It was demonstrated that the parallel cell structure with two concentrated streams can be employed in a large scale CDI for salt removal.

다이아몬드 배열 무전해 니켈 도금층/무산소동 기판의 열전도도 특성

정다운,김송이,박경태,서석준,김택수,김범성,Jeong, Da-Woon,Kim, Song-Yi,Park, Kyoung-Tae,Seo, Seok-Jun,Kim, Taek Soo,Kim, Bum Sung 한국분말야금학회 2015 한국분말재료학회지 (KPMI) Vol.22 No.2

The monolayer engineering diamond particles are aligned on the oxygen free Cu plates with electroless Ni plating layer. The mean diamond particle sizes of 15, 23 and $50{\mu}m$ are used as thermal conductivity pathway for fabricating metal/carbon multi-layer composite material systems. Interconnected void structure of irregular shaped diamond particles allow dense electroless Ni plating layer on Cu plate and fixing them with 37-43% Ni thickness of their mean diameter. The thermal conductivity decrease with increasing measurement temperature up to $150^{\circ}C$ in all diamond size conditions. When the diamond particle size is increased from $15{\mu}m$ to $50{\mu}m$ (Max. 304 W/mK at room temperature) tended to increase thermal conductivity, because the volume fraction of diamond is increased inside plating layer.

PAHs의 환경매체 거동 연구

이민도(Mim-Do Lee),김소영(So-Young Kim),임용재(Yong-Jae Lim),서석준(Seok-Jun Seo),김영환(Young-Hwan Kim),조기철(Ki-Chul Cho) 한국환경관리학회 2010 環境管理學會誌 Vol.16 No.1

본 연구는 다환방향족탄화수소류에 대하여 매체간 거동 및 물리ㆍ화학적 변환 등을 파악하여 대기, 수질, 토양에 대한 평가방법을 구축하고 기초자료를 확보하고자 하였다. 미국 EPA가 개발한 구획모형인 CalTOX 모델을 사용하여 주요 다환방향족탄화수소류의 다매체 거동 및 매체별 분포 특성을 예비모사하였다. 그 결과 run-off 지점의 PAHs 농도 분포 결과, 4개 지점의 총 PAHs 농도는 표토에서 2.34 ~ 49.09 ㎍/㎏, 심토에서 5.96~42.67 ㎍/㎏으로 다양한 농도 범위를 보여주었으며, run-off 지점의 특성을 고려하여 대기 중 PAHs 결과와 함께 수질 및 퇴적토와의 연관성을 고려하여 평가되어야 할 것으로 판단된다. 아산호와 삽교호 인근지역의 8개 매체(대기, 나뭇잎, 표토, 뿌리지역 토양, vadose-zone 토양, 지하수, 지표수, 퇴적물)에 대한 CalTOX 모사결과, 매체별 분포율은 뿌리지역 토양으로 축적되는 것은 40.4~91.0%로 나타났고, 표토층에 축적되는 것은 2.2~5.5%로 나타났다. CalTOX에 의한 일별 매체간 이동량을 모사한 결과, PAHs는 주로 대상지역에 존재하는 석유정제시설로부터 대기로 유입되어 대기중 이류에 의한 모사구간 외부 유출, 매체 내에서 반응기작 및 반감기에 따른 소멸, 뿌리부근토양으로의 침적 등으로 거동되는 것으로 나타났다. This study was carried out to establish the diagnostic method of multi-media fate of pollutants and to monitor the pollutant distribution as a basic study for assessment of environmental toxicity of pollutants. CalTOX model, which is developed to study the multi-media transportation, inter-media production, and sink mechanism of chemicals by U.S. EPA, was used to predict the multimedia characteristics of PAHs in Lake Asan and Lake Sapgyo region. The mean concentration of total PAHs, calculated by summing up gaseous and particulate PAHs in the atmosphere, is Phenanthrene (3.87 ng/㎥) > Fluoranthene (1.48 ng/㎥) > Indeno(1,2,3-cd)pyrene (1.45 ng/㎥) > Benzo(a)pyrene (0.23 ng/㎥) > Benzo(a)antracene (0.15 ng/㎥), in order of concentration. Dry deposition flux, serving as an index for PAHs in the atmosphere, were Phenanthrene(1.48㎍/㎡/day) > Indeno(1,2,3-cd)pyrene(0.31 ㎍/㎡/day)> Fluoranthene(0.28 ㎍/㎡/day) > Benzo(a)pyrene (0.25 ㎍/㎡/day) > Benzo(a)anthracene(0.23 ㎍/㎡/day) in order of high flux. The order of five PAHs compounds in water was Fluoranthene> Phenanthrene> Benzo(a)pyrene> Benzo(a)anthracene, Indeno(1,2,3-cd)pyrene. Concentrations are ranged from <1.0 ng/L to 11.0 ng/L for Phenanthrene, <1.0 ng/L to 13.2 ng/L for Fluoranthene, <0.5 ng/L to 1.0 ㎍/L for Benzo(a)anthracene and <1.0 ng/L to 1.9 ng/L for Benzo(a)pyrene, <0.5 ng/L to 0.8 ng/L for Indeno(1,2,3-cd)pyrene. The ranges of average concentration of PAHs in forest soil, upland soil, and road soil with land use were as followed by soil depth: ND~92.90 ㎍/㎏ for Phenanthrene, 2.15~97.86 ㎍/㎏ for Fluororanthene, ND~32.01 ㎍/㎏ for Benzo(a)anthracene, ND~10.69 ㎍/㎏ for Benzo(a)pyrene, and ND~22.74 ㎍/㎏ for Indeno(1,2,3-cd)pyrene. PAHs concentrations in surface soil were mainly higher than those in subsurface soils. CalTOX model, As a result, accumulations of PAHs into the root-zone soil were about 40.4~91.0%, with 2.2~5.5% of PAHs accumulated on the ground soil. CalTOX simulation showed that the flux of PAHs transported between media flowed mainly in the atmosphere, 7.7~38.9% of which flowed out, 57.4~87.2% of which disappeared, and 0.7~4.3% of which were deposited into the root-zone soil.

PTR-TOF-MS를 이용한 화학사고 원인물질 분석 연구 -에폭시와 아크릴산 이상 반응에 의한 사고 사례-

김기준 ( Ki Joon Kim ),윤영삼 ( Young Sam Yoon ),이진선 ( Jin Seon Lee ),박현주 ( Hyun Ju Park ),서석준 ( Seok Jun Seo ),윤준헌 ( Jun Heon Yoon ),석광설 ( Gwang Seol Seok ),최경희 ( Kyung Hee Choi ) 한국환경분석학회 2014 환경분석과 독성보건 Vol.17 No.1

Over the last 10 years, about 200 chemical accidents have occurred. The frequency of chemical leak accidents has particularly increased since the 2012 accident of hydrogen fluoride gas leakage. When a chemical accident happens, the released gas-phase substances are more likely diffused into the air, which subsequently might cause serious damage to the health of local residents and the environment. To make a quick response to such a chemical accident, it is significantly important to promptly analyze the accident-causing substances. In this study, a cross analysis was performed using PTR-TOF-MS and GC-MS to identify accident-inducing substances generated in the reaction process with brominated epoxy resin and acrylic acid. As a result of the two analyses, acrylic acid was not found to induce a chemical accident, whereas aromatic hydrocarbons and 2-bromophenol were both identified as accident-causing substances. Given that rapid analysis is essential for a prompt response to chemical accidents, the cross analysis using two or more techniques may be useful to quickly identify accident-causing substances.