• 제목/요약/키워드: Speciation

검색결과 324건 처리시간 0.034초

수도권 지역에서 기상-대기질 모델링을 위한 VOC와 PM2.5의 화학종 분류 및 시간분배계수 산정 (Estimation of Chemical Speciation and Temporal Allocation Factor of VOC and PM2.5 for the Weather-Air Quality Modeling in the Seoul Metropolitan Area)

  • 문윤섭
    • 한국지구과학회지
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    • 제36권1호
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    • pp.36-50
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    • 2015
  • 본 연구의 목적은 휘발성 유기화합물(VOC)과 먼지(PM)의 배출원 프로파일로부터 화학종 분류를 할당하고, 성김 행렬 조작자 핵심 배출량 시스템(SMOKE) 내에 배출원 분류코드에 따른 배출원 프로파일의 화학종 분류와 시간분배계수를 수정하는 것이다. 기솔린, 디젤 증기, 도장, 세탁, LPG 등과 같은 VOC 배출원 프로파일로부터 화학 종 분류는 탄소 결합 IV (CBIV) 화학 메커니즘과 주 규모 대기오염연구센터 99 (SAPRC99) 화학 메커니즘을 위해 각각 12종과 34종을 포함한다. 또한 토양, 도로먼지, 가솔린, 디젤차, 산업기원, 도시 소각장, 탄 연소 발전소, 생체 연소, 해안 등과 같은 PM2.5 배출원 프로파일로부터 화학종 분류는 미세 먼지, 유기탄소, 원소 탄소, 질산염과 황산염의 5종으로 할당하였다. 게다가 점 및 선 배출원의 시간 프로파일은 2007년 수도권 지역에서의 굴뚝 원격감시시스템(TMS)과 시간별 교통 흐름 자료로부터 구하였다. 특별히 점 배출원에 있어 오존 모델링을 위한 시간분배계수는 굴뚝 원격감시시스템 자료의 $NO_X$ 배출량 인벤토리에 근거하여 추정하였다.

종분화를 이용한 다품종 하드웨어의 진화 (Diverse Hardware Evolution using Speciation)

  • 황금성;조성배
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2001년도 봄 학술발표논문집 Vol.28 No.1 (B)
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    • pp.307-309
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    • 2001
  • 진화 하드웨어(Evolvable Hardware: EHW)는 환경에 적응하여 스스로 하드웨어 구성을 변경할 수 있어서 근래에 많은 관심을 모으고 있는 분야이다. EHW는 목표 하드웨어를 탐색하기 위해 일반적으로 진화 알고리즘을 사용하는데, 진화 알고리즘은 하나의 목표 하드웨어 탐색 기능만을 수행한다. 본 논문에서는 종분화(Speciation) 알고리즘을 EHW에 적용하여 더욱 다양한 회로들을 얻을 수 있음을 보인다. 종분화 알고리즘은 동시에 여러 종의 해를 발견하게 해주고, 기존 진환 알고리즘에 비해 후반 탐색범위도 넓게 유지된다. 이를 6멀티플렉서의 진화에 적용한 결과, 다양한 품종의 하드웨어를 동시에 얻었고, 기존 진화 알고리즘에 비해 35%정도 빠른 세대에 해를 발견할 수 있었다.

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염화페놀류 화합물의 HDTMA-montmorillonite에 대한 수착 동력학에 미치는 ph의 영향 (Effect of pH on the sorption kinetics of chlorophenols onto HDTMA-montmorillonite)

  • Mun Yong, Gwak;Dong Ik, Song
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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    • pp.186-191
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    • 2004
  • Sorption kinetics of 2-chlorophenol(2-ChP), 2,4-dichlorophenol(2,4-DChP) and 2,4,5-trichlorophenol (2,4,5-TChP), onto montmorillonite modified with hexadecyltrimethyl ammonium cations(HDTMA-mont) were investigated. One-site mass transfer model(OSMTM) and two compartment first-order kinetic model(TCFOKM) were used to analyze kinetics. As expected from the number of model parameters involved, the three-parameter TCFOKM was better than the two-parameter OSMTM in describing sorption and desorption kinetics of chlorophenols in HDTMA-mont. For all chlorophenols, the results of OSMTM analysis indicate that the predominant deprotonated speciation(at pH 9.15) exhibited higher mass transfer coefficient( $k_{s}$ ) than the protonated speciation(at pH 4.85). This is because the deprotonated speciation has stronger hydrophobic interaction than protonated speciation. Most sorption completes in three hours. The fraction of the fast sorption and the first-order sorption rate constants for the fast and slow compartments in TCFOKM were determined by fitting experimental data to the TCFOKM. The results of kinetics reveal that the fraction of the fast sorption( $f_1$) and the sorption rate constants in the fast compartments( $k_1$) were in the order 2,4,5-TChP > 2,4-DChP > 2-ChP, which agrees with the magnitude of the $K_{ow}$ . The first-order sorption rate constants in the fast compartment(10$^{0.8}$ - 10$^{1.22}$ h $r^{-1}$ ) were much larger than those in the slow compartment(10$^{-1}$.74/ - 10$^{-2}$.622/ h $r^{-1}$ ).> ).).

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SMOKE 모델의 입력 모듈 변경에 따른 영향 분석 (Assessment of Changed Input Modules with SMOKE Model)

  • 김지영;김정수;홍지형;정동일;반수진;이용미
    • 한국대기환경학회지
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    • 제24권3호
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    • pp.284-299
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    • 2008
  • Emission input modules was developed to produce emission input data and change some profiles for Sparse Matrix Operator Kernel Emissions (SMOKE) using Clean Air Policy Support System (CAPSS)'s activities and previous studies. Specially, this study was focused to improve chemical speciation and temporal allocation profiles of SMOKE. At first, SCC cord mapping was done. 579 SCC cords of CAPSS were matched with EPA's one. Temporal allocation profiles were changed using CAPSS monthly activities. And Chemical speciation profiles were substituted using Kang et al. (2000) and Lee et al. (2005) studies and Kim et al. (2005) study. Simulation in Seoul Metropolitan Area (Seoul, Incheon, Gyeonggi) using MM5, SMOKE and CMAQ modeling system was done for effect analysis of changed input modules of SMOKE. Emission model results adjusted with new input modules were slightly changed as compared to using EPA's default modules. SMOKE outputs shows that aldehyde emissions were decreased 4.78% after changing chemical profiles, increased 0.85% after implementing new temporal profiles. Toluene emissions were decreased 18.56% by changing chemical speciation profiles, increased 0.67% by replacing temporal profiles as well. Simulated results of air quality were also slightly elevated by using new input modules. Continuous accumulation of domestic data and studies to develop input system for air quality modeling would produce more improved results of air quality prediction.

낙동강 퇴적물 내 중금속 존재 형태 및 용출 가능성 (Speciation and Leaching Potential of Heavy Metals in Sediments of Nakdong River)

  • 황경엽;박성열;백원석;정제호;김영훈;신원식;이남주;황인성
    • 상하수도학회지
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    • 제21권1호
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    • pp.113-122
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    • 2007
  • Experimental studies were performed to investigate speciation and leaching potential of heavy metals(Cu, Cd, Pb Zn, Ni) in ten sediment samples collected from Nakdong River. Acid Volatile Sulfide (AVS) and Simultaneously Extractable Metals (SEM) measurements were used to estimate heavy metals that can be leached under anaerobic conditions. Sequential Extraction Procedure (SEP) and Toxicity Characteristic Leaching Procedure (TCLP) were used to characterize speciation and leaching potential of heavy metals under aerobic conditions. The results show that total concentrations of Cu, Zn and Ni were relatively high in the sediments from points Seongseo industrial complex stream (upper stream) (D), Seongseo industrial complex stream (midstream) (E), Dalseo stream (F), and Nakdong river estuary (J), and that Cd concentrations were higher in all sampling points except for Goriung Bridge (G) and Soosan Bridge (H). SEM and AVS analyses reveal that samples from points Ilsun Bridge (A), Namgumi Bridge (C), and Soosan Bridge (H) have potential of heavy metals leaching, although leachable concentrations are relatively low. The leaching potential of heavy metals in other points was low because of higher concentrations of AVS than SEM. SEP results show that more than 50% of Cu, Zn and Ni were present in residual fraction, which means these metals are less amenable to leaching in anaerobic conditions. On the other hand, more than 50% of Pb and Cd were extracted during the first through third step of the SEP, which means substantial fraction of these metals can be leached upon changing of redox conditions. TCLP tests predict that leaching potential of heavy metals was generally low, which is consistent with the results obtained by AVS and SEM measurements.

디티존 착물 추출과 역상 액체 크로마토그래피를 이용한 물시료 중의 미량 수은 화합물의 농축 및 화학종의 분리 (Preconcentration and Speciation of Trace Mercury Compounds in Water Sample Using Dithizonates Extraction and Reverse Phase Liquid Chromatography)

  • 서정기;조경행;이상학
    • 분석과학
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    • 제13권1호
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    • pp.81-88
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    • 2000
  • 물 중의 미량 수은 화합물을 분리분석하기 위해 초고분자량 폴리에텔렌 막 필터를 이용한 신속 농축방법을 개발하였다. 디티존이 침윤된 폴리에텔렌 막 필터에 시료를 통과시켜 시료 중의 수은을 디티존 착물로서 추출하고, 초음파를 이용해 메탄을 용매상에 회수함으로써 간단하게 농축하였다. 회수된 수은 디티존 착물은 $C_{18}$ 분리관을 이용하여 액체크로마토그래피에 의해 분리하였다. 0.05 M 아세테이트 완충용액(pH 4)과 THF/메탄올(3:5:2)의 혼합액을 이동상으로 사용하여 무기수은과 메틸-, 에틸-, 페닐- 등의 유기수은이 완전 분리되었다. 분리된 수은 착물은 475 nm의 파장에서 검출하였다. 이 방법을 폐수시료에 응용한 결과 ng/mL이하 수준의 검출한계로서 수은 화합물의 분리분석이 가능함을 확인하였다.

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공업지역 대기 중 입자에 함유된 미량금속의 화학종별 분석 (Chemical Speciation of Trace Metals in Airborne Particles at An Industrialized Site)

  • 정기호;이지영;문지용;이성인
    • 한국환경과학회지
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    • 제15권6호
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    • pp.503-511
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    • 2006
  • Airborne particles collected from a heavily industrialized site were analyzed by chemical speciation of seven trace metals: Pb, Cd, Cr, Cu, Ni, Zn, and As. The average concentrations were as follows: $Zn,\;502.0{\pm}230.7;\;Pb,\;176.5{\pm}310.9;\;Cu,\;111.9{\pm}82.7;\;As,\;38.0{\pm}31.0;\;Cr,\;21.5{\pm}24.4;\;Cd,\;20.8{\pm}17.4;\;and\;Ni,\;11.4{\pm}8.4\;ng/m^3$. The median enrichment factor (EF) values of Cd (7,280), As (1,030), Cu (215), Zn (214), and Pb (143), with respect to iron, were much larger than 100. We observed that Cd was found in the soluble and exchange- able form (56.9%), and that Pb and Cr were found in carbonates, oxides and the reducible form (69.8% and 61.1%, respectively). These two forms, which are the most easily absorbed into human body tissue, predominated in most of the trace metals investigated in this study.

유기오염물의 분해에 의한 오염토양내 비소종 변화 영향

  • 천찬란;이상훈
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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    • pp.347-350
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    • 2002
  • Arsenic speciation changes between As(V) and As(III) are subject to changes in accordance with redox conditions in the environment. It is common to find contaminated sites associated with mixed wastes including both organic pollutants and heavy metals. We conducted microcosm experiment under hypothesis that the co-disposed organic pollutants would influence on the arsenic forms and concentrations, via degradation of the organic pollutants and the consequent impact on the redox conditions in soil. Artificially contaminated soil samples were run for 40 days with control samples without artificial contamination. We noticed arsenic in the contaminated soil showed different behaviour compared with the arsenic in the control soil. The findings indicate degradation of organic pollutants in the contaminated soil influenced on the arsenic speciation and concentrations. A further work is needed to understand the process quantitatively. However, we could confirm that degradation of organic pollutants can influence on the abiotic processes associated with geochemical reactions in contaminated soil. Degradation of organic pollutants can increase the mobility and toxicity of arsenic in soil and sediment by changing redox conditions in the geological media and subsequently from As(V) to As(III).

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Effect of Rotary Drum on the Speciation of Heavy Metals during Water Hyacinth Composting

  • Singh, Jiwan;Kalamdhad, Ajay S.
    • Environmental Engineering Research
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    • 제18권3호
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    • pp.177-189
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    • 2013
  • Studies were carried out on the speciation of heavy metals (Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr) during rotary drum composting of water hyacinth (Eichhornia crassipes) for a period of 20 days. Five different proportions of cattle manure, water hyacinth and sawdust were prepared for composting. This study concluded that, rotary drum was very efficient for the degradation of organic matter as well as for the reduction of mobility and bioavailability of heavy metals during water hyacinth composting. The results from the sequential extraction procedure of heavy metals shows that rotary drum composting changed the distribution of five fractions of Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr. The highest reduction in the bioavailability factors of Pb and Cd was observed during the process. The total concentration of Cu, Cr, and Cd was very low compared to the other metals (Zn, Mn, Fe, Ni, and Pb); however, the percentage of exchangeable and carbonate fractions of these metals was similar to other metals. These results confirmed that the bioavailability of metals does not depend on the total concentration of metals. From this study, it can be concluded that the addition of an appropriate proportion of cattle manure significantly reduced the mobile and easily available fractions (exchangeable and carbonate fractions) during water hyacinth composting in rotary drum.