This study analyses the characteristics of volatile organic compounds (VOCs) emissions from the painting and printing facilities, as well as ambient VOCs at industrial complexes in Gwangju. The major components of VOCs emissions from painting facilities were toluene, acetone, 2-butanone, ethyl acetate, ethyl benzene, o-xylene and m,p-xylene. The printing facilities mostly emitted ethyl acetate, 2-butanone, acetone and toluene. Aromatics (49.9%) and oxygenated VOCs (43.6%) were dominant in painting facilities, while oxygenated VOCs (92.7%) were the largest group in printing facilities. The total hydrocarbon concentration (THC) in printing facilities was approximately six times higher than in the painting facilities. The painting and printing facilities use many solvents. Their THC concentrations differed considerably depending on the type of prevention facilities. To reduce THC, it is necessary to improve the prevention facilities and operating conditions. The dominant species of ambient VOCs in industrial complexes were investigated with toluene, ethyl acetate, 2-butanone, ethyl benzene, m,p-xylene, butyl acetate, o-xylene, hexane and acetone. Factor analysis of ambient VOCs showed that the main sources of the VOCs were organic solvents used in painting, coating, and printing, as well as automobile emissions.
수은의 전과정 관리를 통한 환경배출 저감을 위한 미나마타 협약이 2017년 8월에 발효되면서 비준 절차를 진행하고 있는 우리나라 또한 수은을 함유한 제품 또는 폐기물을 친환경적으로 보관 및 폐기해야 한다. 우리나라는 의도적 사용을 위해 원소상 수은을 수입해 왔으나, 수은첨가제품 및 정광 불순물 등 비의도적으로 수은이 유입되어 왔다. 이렇게 비의도적으로 유입된 수은의 69%가 고농도 수은함유폐기물의 형태로 지정폐기물로 구분되어 지정폐기물 유입시설로 유입되고 있는 것으로 추정되고 있다. 그러나 수은함유 폐기물 매립시설 주변대기 중 수은 농도가 우려됨에 따라 수은함유 폐기물의 친환경적인 매립 관리기준과 함께 고수은함유폐기물의 회수 및 처리에 대한 관심이 높아지고 있다. 특히 수은은 대기로의 휘발량이 큰 금속으로 알려져 있으며, 수은함유 폐기물 매립지에서 원소상 수은의 형태로 전환되어 환경 중으로 재유입될 가능성이 있다. 국외의 경우 고농도 수은함유 폐기물의 회수 및 처리에 대한 기준을 두고 있으나 국내에서는 아직 수은 회수에 대한 법적 근거가 마련되어 있지 않은 상황이다. 본 연구에서는 국내 업체에서 발생하고 있는 고농도 수은함유폐기물(비철금속 발생 슬러지)을 대상으로 시간별 온도별에 따른 대상 폐기물 내 수은 함유량 및 용출량 실측을 통해 고농도 수은함유 슬러지 중 최대 비산율 및 온도별 속도상수를 구하고자 하였다. 이를 통해 고농도 수은함유 폐기물의 환경 중 수은 배출 저감 방향을 제시함으로 향후 수은함유 폐기물의 적정 관리기준 설정에 기초자료로 활용될 것으로 판단된다.
Koreans have sedentary lifestyles and use under-floor heating called Ondol as home heating systems. Sick Building Syndrome (SBS) caused by VOCs released from flooring material has been of significant interest in residential apartments. In this study, we measured exposure to VOCs by having test subjects breathe under conditions of high surface temperature. The results showed that the emission level of VOCs was high at 40oC in the early stage of the experiment. However, 20 days after the experiment began, the emission level was reduced by 0.9-4 times in each product at 40oC. The exposure to VOCs released from floor coverings was measured by taking into account the average respiratory rate, weight, and activity hour of test subjects and presuming that people are exposed to VOCs all the time while staying indoors. The level of emission from FJR of low-cost PVC floor coverings was the highest among the tested coverings, but the exposure to VOCs emission from the covering was relatively low at 0.025 mg/kg/day at 40oC. The amount of toluene detected from this experiment was the highest among VOCs emitted from floor coverings. The hazard quotient (HQ) of toluene detected in this test was over 20 times smaller than the risk characterization level of 0.1. It was, therefore, estimated that the emission of toluene from the floor surface would not be critically harmful to residents.
Volatile organic silicon compounds (namely as siloxanes) are impurities in biogas generated from landfill and biogas.They have been known to cause damages to gas combustion engines. However, factors affecting process design decisionshave been less studied. In this research, we experimentally determined the gas-liquid partition coefficients (Kp) of siloxanesby applied the equilibrium partition experiment in closed system. we also investigated the effects of liquid solutes onsiloxanes partitioning. Five different types of siloxanes and five different types of liquid solutes (distilled water, nutrientsolution, ferrous sulfate solution, and surfactant solutions) were selected for this study. Dimensionless gas-liquid partitioncoefficients of siloxanes were determined to be 8.808 for L2, 2.278 for L3, 1.455 for L4, 3.435 for D4, and 0.770 forD5. Partition coefficients varied by liquid solutes, Especially for surfactants as liquid solutes, mass transfer of siloxanesfrom gas to liquid was enhanced, showing the lowest coefficients of partitioning.
This study assessed the analysis method for measuring volatile organic silicon compounds (namely as siloxanes) by usinggas chromatography with flame ionization detector. Calibration standard gas was made in a laboratory by using six volatileorganic silicons as model gas. Two different types of working gas were prepared to evaluate quality control in GC-FIDanalysis. Less than 0.2 RSD% of repeatability of retention time was observed in the analysis of calibration standard gas. Inthe linearity test, the highest coefficient of determination (R2) was found to be 0.997 for L2 among volatile organic siliconcompounds. This study demonstrated that quantification of volatile organic silicon compounds can be performed by usingGC-FID analysis with direct injection mode, and the GC calibration can be covered by the gas-phase standard method.
유기성폐기물 처리 시 발생되는 매립가스 및 혐기성소화가스는 높은 메탄함량으로 인해 연소를 통한 열 회수나 발전 등의 방법으로 자원화가 활발히 진행되고 있다. 그러나 바이오가스 중에는 다양한 미량물질 가운데 휘발성유기규소화합물은 연소에 의해 이산화규소를 형성하고 가스엔진이나 가스터빈 등의 고비용 설비에 축적되어 기기손상 및 자원화효율 저하를 유발한다. 따라서 최근 휘발성유기규소화합물인 실록산은 바이오가스 연소 전에 필수적으로 제거해야 하는 물질로 인식되고 있으며, 이를 위한 다양한 제거방법 연구 중에서는 흡착제거가 가장 일반적인 방법으로 보고되고 있다. 본 연구에서는 활성탄 및 고분자 trap 역할에 주로 이용되는 제올라이트를 이용하여 실록산의 흡착제거 성능을 평가하고자 하였다. 흡착제로는 다양한 제올라이트(A형, X형, Y형, β형 제올라이트 및 ZSM-5)와 일반적인 흡착제인 활성탄을 결과 비교를 위하여 사용하였으며, 실록산은 매립가스 중 가장 높은 빈도와 농도로 발생되는 oxtamethyl-cyclo-tetrasiloxane (D4)를 흡착질로 사용하였다. 등온에서의 흡착평형실험결과, D4 흡착용량은 activated carbon의 및 β형 제올라이트가 43 mg/g, ZSM-5 및 A형 제올라이트가 각각 24, 16 mg/g으로 나타났고, X형과 Y형 제올라이트는 2 mg/g 미만으로 흡착효과가 거의 나타나지 않았다. 일반적으로 제올라이트는 분자체 역할을 하는 동공(cavity)의 모양 및 사이즈에 의해 흡착특성이 결정되는 것으로 알려져 있으나, 본 결과에서는 실록산(D4)은 제올라이트의 극성에 의한 선택성의 영향이 더 큰 것으로 나타났다.
In order to study the seasonal patterns and possible origins of air concentrations of volatile organic compounds(VOC), measurements were taken with GC-MS at 3 sampling sites in Jinju for 12 months from Mar. 2010 to Feb. 2011. Atmospheric VOC are sampled on tubes containing solid adsorbents(Tenax TA) with a time resolution of 2hrs. Composition and concentration of VOC are analysed with a GC system equipped with thermal desorption apparatus(ATD).
The most abundant compound appeared to be Toluene, Ethylbenzene and m,p-Xylene. The mean concentrations of Benzene were 0.20 ppb at GN site, 0.18 ppb at DA site, and 0.25 ppb at SP site, respectively. VOC concentration showed a strong seasonal variation, with higher concentrations during the spring and lower concentrations during the summer. The results showed that monthly fluctuations in measured VOC concentrations depended on variations in the strength of sources, as well as on photochemical activity and meteorological conditions. In Jinju, the total VOC emissions for 2009 were estimated to be 4,407 ton/year by Clean Air Policy Support System(CAPSS). It is shown that solvent use 57.5%(2,534 ton/yr), waste treatment and disposal 23.3%(1,025 ton/yr), and mobil source-road traffic 12.2%(537 ton/yr) are the most significant anthropogenic source.
본 연구는 정치발효에 의한 국산 및 일본산 현미식초의 품질비교를 실시하였다. 국내산 현미식초의 주요 유리아미노산은 proline, glutamic acid와 phenylalanine인 반면, 일본산 현미식초는 proline, valine, phenylalanine, lysine, -aminobutyric acid, alanine과 isoleucine이었다. -aminobutyric acid (GABA)와 총아미노산 함량(3686.37~4212.2
This study was designed to evaluate qualitatively and quantitatively the pollutant compositions, which were emitted from three types of mosquito repellents(MRs)(mat-, liquid-vaporized, and coil-type) by utilizing a 50-L environmental chamber. A qualitative analysis revealed that 42 compounds were detected on the gas chromatography/ mass spectrometer system, and that the detection frequency depended upon chemical types. Nine of the 42 compounds exhibited a detection frequency of 100%. Four aromatic compounds(benzene, ethyl benzene, toluene, and xylene) were detected in all test MRs. The concentration equilibriums in the environmental chamber were achieved within 180 min after sample introduction. The coil-type MR represented higher chamber concentrations as compared with the mat- or liquid-vaporized-type MR, with respect to the target compounds except for naphthalene. In particular, the chamber concentrations of ethyl benzene, associated with the use of coil-type MR, were between 0.9 and 65 mg m-3, whereas those of mat- and liquid-vaporized-type MRs were between 0.5 and 2.0 mg m-3and 0.3 and 1.4 mg m-3, respectively. However, naphthalene concentrations in the chamber, where a liquid-vaporized-type MR was placed, were measured as between 17.8 and 56.3 mg m-3, but not detected in the chamber, where a mat- or coil-type MR was placed. The empirical model fitted well with the time-series concentrations in the environmental chamber(in most cases, determination coefficient, R2 ≳ 0.9), thereby suggesting that the model was suitable for testing emissions. In regards to the target compounds except for benzene, although they were emitted from the MRs, health risk from individual exposure to them were estimated not to be significant when comparing exposure levels with no observed adverse exposure levels or lowest observed adverse exposure levels of corresponding compounds. However, it was concluded that the use of MRs could be an important indoor source as regards benzene.
Emission characteristics of volatile organic compounds (VOCs) were investigated in the flue gas emitted from wood drying process for plywood manufacturing. The moisture content of raw timber was average 48%, and its density was 831.55 kg/m3. But the moisture content of dried wood is needed less than around 10%, thus the moisture contents of flue gas should be remarkably high(about 18.2 V/V%). Therefore, the vapor in flue gas is equivalent to 320 ton-vapor/day when 1100 ton-wood/day is treated in the wood drying process. The temperature of flue gas ranges from 140℃ to 150℃ in each dryer stack with exception of the input site of wood(about 110℃). The velocity of flue gas in each stack ranges from 1.7 to 9.7 m/sec. In order to assess the concentrations and attribution rate of odorous compounds, it was analyzed about 40 VOCs in the flue gases. It was found that the major odorous compounds were 8 compounds, and the concentrations of major VOCs(ppm) were as follows; benzene: 0.054~0.052, toluene: 1.011~2.547, ethylbenzene: 0.472~2.023, m,p-xylene: 0.504~3.245, styrene: 0.015~0.148, o-xylene : 0.271~1.097, ethanol: 11.2~32.5, α-pinene: 0.908~10.578, β-pinene: 0.982~14.278. The attribution rate of terpenes (α-pinene, β-pinene) was about 60.56%, and that of aromatics and alcohols was about 22.77%, and 16.67%, respectively. It is suggested that the adequate control device should be used to control both the water soluble and non-soluble compounds because both compounds were mixed in flue gas.