The emission of particulate matter and volatile organic compounds (VOCs) from a motor vehicle painting booth was quantitatively evaluated. Most particulate matter was emitted during the spraying process, in which the PM10 concentration was 16.5 times higher than that of the drying process. When the paint was being sprayed, the particles with a diameter of 1.0~2.5 μm accounted for 39.4% and particles greater than 2.5 μm in diameter accounted for 30.6% of total particles. On the other hand, small particles less than 0.5 μm in diameter accounted for 52.4% of total particles during the drying process. In contrast to the particulate matter, high concentrations of VOCs were emitted during both spraying and drying processes. Butyl acetate, xylene, toluene, and m-ethyltoluene were the most abundant VOCs emitted from the motor vehicle painting booth. Additionally, xylene, butyl acetate, toluene, and 1,2,3-trimethylbenzene were the dominant ozone precursors. Especially, xylene exhibited the highest ozone production contribution (32.5~44.4%) among 34 species of the ozone precursors. The information obtained in this study can be used to establish a suitable management strategy for air pollutants from motor vehicle painting booths.
In this study, we listed the VOCs focusing on ozone precursors emitted from printing shops in urban areas. The emission characteristics of the VOCs from workplaces were evaluated in terms of the used inks. As a result of field measurements, more than 80% of detected VOCs showed high values of photochemical ozone creation potential (POCP). The main species were aromatic hydrocarbons such as ethylbenzene, toluene, ethyltoluene, xylene, trimethylbenzene and their isomers, and paraffin hydrocarbons such as nonane, decane, and octane. Comparative examination between pristine ink and the printing process revealed the emission of hydrocarbons with 8 to 12 carbons such as o-xylene to n-dodecane from the used inks and with 3 to 7 carbons such as acetone to 3-methylhexane from the printing process. The major contributors to ozone production in printing industries were toluene (12.2%), heptane (7.43%), and 1,2,3-trimethylbenzene (7.21%) in every step.
This study was carried out to investigate the effect of malodor and VOCs reduction that could be achieved through the installation of a vapor recovery system (VRS) in a gas station. It was revealed that the reduction efficiencies of malodor by running VRS were about 93% around the oil feeder, 32% in the office and 45% in the site boundary. Specifically, it was remarkable that reduction efficiencies of BTEX over 90% were recorded through VRS operation. In addition, the results of continuous monitoring of THC around the oil feeder device provided good evidence of the inhibition of oil mist diffusion after running VRS.
Volatile organic compounds(VOCs) are harmful substances that contribute to stratospheric ozone depletion, tropospheric photochemical ozone formation, and carcinogenic human health effects. Worldwide, there are major concerns over the emission of VOCs. Any plans for pollution reduction and management should be established based on database of VOC emission and characteristics. In this paper, the status of VOCs by year, region, and industry were investigated, and then technologies for VOC emission control were introduced. The estimation of VOC emissions by year was gradually increased, and VOC emission due to the utilization of organic solvents was the most common form. VOCs in the atmosphere were detected at the highest concentration in industrial complexes. In most of the industry, it was confirmed that emissions of toluene were the highest among the VOCs. Finally, available VOCs control technologies were introduced, including thermal and catalytic oxidation, adsorption, absorption, biological treatment, non-thermal plasma, electron beam irradiation, and photocatalyst.
There has been a growing concern about the emissions of formaldehyde and VOCs from automotive interior materials which could have an important impact on the in-vehicle air quality(IVAQ) of automotive vehicles. Many leading automobile manufacturers have now introduced their own specification standards for testing and limiting emissions from products produced by their suppliers. In addition, ISO (International Standard Organization) has been established ISO 12219-1, 2, 3, 4, 5 to determine the emissions of volatile organic compounds from automotive vehicle. The objective of this paper is to compare the area specific emission rates determined from surface emissions testing using the microchamber(MC) in comparison with a 1 m3 emission test chamber(ETC) operated in accordance with ISO 12219-3, ISO 12219-4. Measured emission concentrations in absolute terms were different between Microchamber and 1 m3 chamber. However, qualitative comparison of the chromatograms shows that the Microchamber is able to perform a screening test
This study was performed to analysis the concentration of TVOC, 5VOC and formaldehyde for building material of total 262 using 20L test chamber. The concentration of TVOC, 5VOC and formaldehyde were measured 1.001㎎/㎡・h, 43.032㎍/㎡・h, 0.012㎎/㎡・h, respectively. TVOC concentration of paint and floor covering occupied the largest concentration of the indoor building materials as 2.689㎎/㎡・h, 2.120㎎/㎡・h, respectively. 5VOC concentration of floor covering was measured 106.636㎍/㎡・h. Toulene and xylene were occupied the largest part of the 5VOC as 51.2% and 33.1%, respectively. The concentration of formaldehyde for furniture materials occupied the largest concentration of the indoor building material as 0.072㎎/㎡h.
주차장 바닥재로 많이 사용되는 A사 에폭시 코팅제와 B사 바닥코팅제(A, B type)에 대하여 GC/MS(Gaschromatography /Mass spectrometer)를 이용하여 제품별로 함유하고 있는 휘발성유기화합물(VOCs)의 종류와 함량을 측정해보고, 휘발성유기화합물(VOCs)중 작업자나 입주자들에게 유해한 폼알데하이드(Formaldehyde), 톨루엔(Toluene), 크실렌(Xylene)을 외부 환경에 따른 오차를 줄이고자 가장 안 좋은 (밀폐) 환경을 가정하고 가스검지관을 이용하여 가스배출량을 측정해 보았다. 그 결과 A사 에폭시코팅제가 제품 자체에도 휘발성유기화합물(VOCs)을 가장 많은 양 함유하고 있고, A사 에폭시코팅제에 비하여 B사 바닥코팅제 A type은 약 79%, B type은 약 96% 이상의 적은 양을 나타냈다. 또한, 밀폐된 환경 조건에서 1시간과 8시간 경과 후 가스검지관을 이용하여 폼알데하이드(Formaldehyde), 톨루엔(Toluene), 크실렌(Xylene)에 대한 가스배출량을 측정하고 TWA값으로 환산한 결과에서도 A사 에폭시코팅제가 가장 높게 측정되었다. A사 에폭시코팅제보다 B사 바닥코팅제 A type은 약 42.3%이상의 적은 측정값을 나타냈으며, B type의 경우 밀폐된 환경 조건에서도 시간가중평균노출기준(TWA)을 모두 만족하였다.
This study characterized PM and VOC emissions from cow dung combustion in a controlled experiment. Dung from grass-fed cows was dried and combusted using a dual cone calorimeter. Heat fluxes of 10, 25, and 50 kW/m² were applied. The concentrations of PM and VOCs were determined using a dust spectrometer and gas chromatography/mass spectrometry, respectively. PM and VOC emission factors were much higher for the lower heat flux, implying a fire ignition stage. When the heat flux was 50 kW/m², the CO₂ emission factor was highest and the PM and VOC emission factors were lowest. Particle concentrations were highest in the 0.23-0.3-μm size range at heat fluxes of 25 kW/m² and 50 kW/m². Various toxic VOCs including acetone, methyl ethyl ketone, benzene, and toluene were detected at high concentrations. Although PM and VOC emission factors at 50 kW/m² were lower, they were high enough to cause extremely high indoor air pollution. The characteristics of PM and VOC emissions from cow dung combustion indicated potential health effects of indoor air pollution in developing countries.
Emission rate of monoterpene and isoprene was measured in five commonly growing tree species of conifers(Pinus thunbergii, Abies koreana, Cryptomeria japonica, Pinus densiflora, Chamaecyparis obtusa) at the Halla mountain sites. Dynamic flow enclosure technique was used and gas samples were collected into Tenax tube. The highest and lowest hourly emission rate was observed in Abies koreana (1.86 ㎍/gdw/hr) and Chamaecyparis obtusa (0.52 ㎍/gdw/hr), respectively. The major species of monoterpene from pine trees were α-pinene, β-pinene, β-phellandrene, myrcene. Particularly, d-limonene was abundant in Abies koreana but α-pinene, d 3 -carene and sabinene was in Cryptomeria japonica. Emission rates of isoprene show less significant than those of monoterpene. And also seasonal emission rates of monoterpene were dependent on environmental factors such as temperature.
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.
It will be necessary to make proper management plans to preserve the air quality in good level for the public. In order to make these plans, source information and detail emission inventories of the city and near industrial areas should be given. However, lack of the source measurements data makes us more difficult to complete the source inventory. VOC source inventory could be utilized for the feasibility study to estimate the contribution of VOC sources presenting to the receptor such as residential area. It may give policy maker an idea how to control the air quality, and improve their social environment in the area. This study shows data that measured VOCs concentrations from the local industrial areas in Jeonju during from May 2005 to January 2006. The samples were collected from the near sources in 7 major factories in the industrial park as well as 5 general sources in near city Jeonju area to elucidate the abundances of speciated VOCs and their spacial and temporal distributions depending on source bases. Industrial sources are as follows; chemical, food, paper, wood, metal, non-metal (glass), and painting (coating) industries. The 5 general sources are sampled from tunnel, gasoline gas station, dry cleaning shop, printing (copy) shop, and road pavement working place in urban area. To understand the near source effect at receptor, samples from the 2 receptor sites (one is at center of the industrial complex and the other site is at distance residential area downwind from the center) were collected and analyzed for the comparison to source concentration. The mass contributions of the speciated VOC to total mass of VOCs measured from the different sources and ambient (2 receptors) were presented and discussed.