• Analytical Science and Technology
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• v.30 no.6
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• pp.329-337
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• 2017

A major concern regarding most auto-repair shops in residential areas is the emission of odorous volatile organic compounds (VOCs) into the local atmosphere, especially during painting operations. VOCs contribute to poor local air quality and are responsible for the perceived odor and discomfort experienced by local residents. Sixteen major VOCs (6 aromatic hydrocarbons and 10 aliphatic carbonyl compounds) were selected as potential target compounds. The site was an auto-repair shop located in a central region of Seoul, South Korea, where the air quality of the site has been a subject of residents' complaints. The sampling points were as follows: 1) in the painting booth with new (NB) or old (OB) removal system, (2) in the exhaust duct after new (ND) or old (OD) odor removal filter, and (3) 2 m below the discharge vent (4 m above the ground) (outdoor air, OA). Each sample was coded: (1) before painting (BP), (2) during painting (DP), and (3) after painting (AP). The toluene level in the duct with the new removal filter during painting (ND-DP) was 1.5 ppm (v/v), while it was 3.8 ppm (v/v) in the right duct with an old removal filter during painting (OD-DP). Accordingly, the effect of filter replacement was reflected by differences in VOC levels. Therefore, accurate monitoring of odorous VOCs is an important step to reduce odor nuisance from local sources.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.2
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• pp.95-109
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• 2014

In this study, the concentration of odorants released from albumin (EA) and yolk (EY) portions of boiled egg samples were determined as a function of storage time. The concentrations were measured at storage days of 0, 1, 3, 6, and 9 under room temperature. As such, odorants produced during both fresh and decay conditions were measured through time. A total of 19 compounds were selected as the main target odorants along with 12 reference compounds. GC-MS (for VOC) and GC-PFPD system (for sulfur gases) equipped with thermal desorption (TD) system were employed for odorant analysis in this work. The initial concentrations measured from the chamber system were converted into flux terms ($ng{\cdot}g^{-1}{\cdot}min^{-1}$). The EA showed the highest concentration of $H_2S$ (234 $ng{\cdot}g^{-1}{\cdot}min^{-1}$) at EA-0, and the concentrations of AT (Acetone) was also seen clearly in the range of 11.7 (EA-0) to 58.6 $ng{\cdot}g^{-1}{\cdot}min^{-1}$ (EA-9). The EY showed similar patterns. EtAl (Ethyl alcohol) increased 9.47 (EA-1) to 96.7 $ng{\cdot}g^{-1}{\cdot}min^{-1}$ (EA-9) in EA samples. Ketone, alcohol, sulfur groups generally exhibited high concentrations compared to other odorants. These data were also compared in relation to olfactometry related dilution-to-threshold (D/T) ratio by air dilution sensory (ADS) test and sum of odor intensity (SOI).

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.83-96
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• 2005

The purposes of this study were to characterize the local levels of VOCs (volatile organic compounds), to develop source profiles of VOCs, and to quantify the source contribution of VOCs using the CMB (chemical mass balance) model. The concentration of VOCs had been measured every 6-day duration in the SRO monitoring site in the Yeosu Petrochemical Industrial Complex from September 2000 to August 2002. The total of 35 target VOCs, which were included in the TO-14 designated from the U.S. EPA, was selected to be monitored in the study area. During a 24-h period, the ambient VOCs were sampled by using canisters placing about 10 ～ 15 m above the ground level. The collected canisters were then analyzed by a GC-MS in the laboratory. Aside from ambient sampling at the SRO site, the VOCs had been intensively and massively measured from 8 direct sources and 4 general sources in the study area. The results obtained in the study were as follows; first, the annual mean concentrations of the target VOCs were widely distributed regardless of monitoring sites in the Yeosu Petrochemical Industrial Complex. In particular, the concentrations of BTX (Benzene, Toluene, Xylene), vinyl chloride were higher than other target compounds. Second, based on these source sample data, source profiles for VOCs were developed to apply a receptor model, the CMB model. Third, the results of source apportionment study for the VOCs in the SRO Site were as follows; The source of petrochemical plant was apportioned by 31.3% in terms of VOCs mass. The site was also affected by 16.7% from wastewater treatment plant, 14.0% from iron mills, 8.4% from refineries, 4.4% from oil storage, 3.8% from automobiles, 2.3% from fertilizer, 2.3% from painting, 2.2% from waste incinerator, 0.6% from graphic art, and 0.4% from gasoline vapor sources.

• Journal of Adhesion and Interface
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• v.20 no.4
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• pp.140-145
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• 2019

In view of environmental considerations, the control of carbon dioxide (CO₂) and volatile organic compounds (VOCs) is one of important issues in the film and coating industries. Therefore, UV-curable system has been developed due to minimize emissions of VOCs and reduce CO₂ emission due to low energy consumption from fast curing. Also, biodegradable polymers economically are attractive because of environmental and economic concerns associated with huge waste plastics. In this study, UV-curable polyurethane acrylates with different compositions of biodegradable polylactide (PLA) diol and poly(ethylene glycol) as diols were synthesized and curing reaction of their end-capped acrylates was performed by UV exposure. Tensile strength, elongation, and Tg of the UV-cured polyurethane acrylates increased with PLA diol content in the diol while their hydrophilicity and thermal stability increased with the PEG content. These results indicated a property of UV-cured polyurethane acrylates could be controlled by environment-friendly diols.

• Journal of Environmental Science International
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• v.29 no.5
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• pp.559-573
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• 2020

The purpose of this study analyzed the overview of corrugated cardboasrd manufacturing industry and then provide direction for improvement. The BREF (BAT reference document) is an important reference for licensees and officer, including the best available techniques for the industry and achievable environmental performance, technical characteristics, and economic information. In the corrugated cardboard manufacturing process, wastewater pollutants are generated throughout the production process, and water is used in the dissociation and aging process. Atmospheric emissions are mostly generated by steam production from boilers and incinerators for the dry process. SO₂, NOx, CO₂, CO, HCl, dust, VOC, and odor were common. In the EU-BREF (European union BAT reference documents) BAT for wastewater have taken up a relatively large proportion. Items of water pollutants in wastewater were common in COD, BOD, N, P, SS, and however EU-BREF had different pollutants such as AOX and salt compared to K-BREF. In order to improve the quality of the K-BREF, it is necessary to devise basic data research method and data acqusitiom method. Consideration should be given to additional environmental management techniques that reflect the emissions characteristics of the corrugated cardboard manufacturing process. In addition, further research is needed to develop methodologies for selecting BATs considering environmental and economic feasibility.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.83-90
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• 2007

This study aimed at examining the effect of rooms decorated by eco-friendly finishing materials in a newly built wooden house on the emission of indoor air pollutions. According to the results of examination, the levels of benzene, toluene, ethyl benzene and styrene in all the rooms were below criteria of indoor air quality of newly-constructed houses. The levels of natural volatile organic compounds (NVOC), anthropogenic volatile organic compounds (AVOC) and total volatile organic compounds (TVOC) in room R1-1 which had Hwangto wall covering on it, were relatively higher than in room phytoncide wallpaper covered R2-1. The room R2-2 where bamboo charcoal panel used for wall covering showed higher level of AVOC compared to the room R1-2. Living room R1-3 was found to contain less TVOC, compared to the other four rooms. In addition, the ratio of NVOC to TVOC in the living room was higher than in the other rooms. This seemed to be attributed to Cryptomeria Japonica the living room finished material.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.91-101
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• 2000

The emission sources of volatile organic compounds (VOCs) are wastewater treatment plants. sanitary landfills, automobile industries, and so on. The VOCs are harmful to human beings because of their toxicity and carcinogenicity, and cause the serious air pollution problem producing ozone ($O_3$) as a result of photochemical reaction. To investigate the emission of VOCs from wastewater treatment plant, aeration basins at the City of Los Angeles' Hyperion Treatment Plant were selected and measured flux was compared with calculated flux. For compounds commonly associated with wastewater (DCM, TCM, PCE, UM, DCB, UND) and not expected in vehicle exhaust or ambient air coming off the ocean, concentrations immediately downwind of the aeration basins were a factor of ten or higher than those measured in the upwind air. The airborne flux of less degradable or non-biodegradable compounds, e.g., DCE, DCM, TCA, DCA, TCM, PCE, DCB, through an imaginary plane at the downwind side of the aeration basins was in agreement with the estimated flux from measured liquid phase concentrations. Henry's constant. aeration rate, and an assumption of bubble saturation. For several compounds (PCE, DCE, TCA), the ratio (measured flux/calculated flux) is almost unity.

• Analytical Science and Technology
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• v.25 no.6
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• pp.447-459
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• 2012

In this study, the emission characteristics of volatile and odorant species released from salted meat product (Spam) was investigated as a function of time. Gas samples released from Spam samples were analyzed for volatile organic compounds (VOC) and sulfur compounds (RSC) at five different times for the elapsed (E) days of 0, 1, 3, 6, and 9 (E-0 to E-9) by GC/MS and GC/PFPD system, respectively. Results indicated that reduced sulfur, aldehyde, and ketone groups were the dominant odorants. Especially, hydrogen sulfide was the predominant in concentration and odor activity value (OAV) during the fresh stage. Its concentration was 1465 ${\mu}g/m^3$ (60.0% of the total mass) in E-0 and 455 ${\mu}g/m^3$ (28.0%) in E-1, while its OAV was 19.4 (78.3%: E-0) and 6.02 (41.7%: E-1). On the other hand, the concentration of acetone showed the maximum values in the decaying stage (E-3: 451 (43.2%), E-6: 369 (64.2%), and E-9: 1150 ${\mu}g/m^3$ (70.2%)). Furthermore, the concentration of 2,3-butanedione was also detected considerably from decaying sample (E-3: 17.6 (1.68%), E-6: 16.1 (2.80%), and E-9: 179 ${\mu}g/m^3$ (10.9%)). However, OAV of acetone was insignificant (<0.01%) in the decaying stage, while that of 2,3-butanedione was relatively high in the range of 1.14-11.6 (14.5-76.2% of ${\Sigma}OAV$). It thus confirmed that the major odorant groups generated from Spam samples changed with the progress of decay such as sulfur (fresh stage), aldehyde (intermediate stage), and ketone compounds (decaying stage).

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.490.2-490.2
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• 2014

Since the general solar cells accept sun light at the front side, excluding the electrode area, electrons move from the emitter to the front electrode and start to collect at the grid edge. Thus the edge of gridline can be important for electrical properties of screen-printed silicon solar cells. In this study, the improvement of electrical properties in screen-printed crystalline silicon solar cells by contact treatment of grid edge was investigated. The samples with $60{\Omega}/{\square}$ and $70{\Omega}/{\square}$ emitter were prepared. After front side of samples was deposited by SiNx commercial Ag paste and Al paste were printed at front side and rear side respectively. Each sample was co-fired between $670^{\circ}C$ and $780^{\circ}C$ in the rapid thermal processing (RTP). After the firing process, the cells were dipped in 2.5% hydrofluoric acid (HF) at room temperature for various times under 60 seconds and then rinsed in deionized water. (This is called "contact treatment") After dipping in HF for a certain period, the samples from each firing condition were compared by measurement. Cell performances were measured by Suns-Voc, solar simulator, the transfer length method and a field emission scanning electron microscope. According to HF treatment, once the thin glass layer at the grid edge was etched, the current transport was changed from tunneling via Ag colloids in the glass layer to direct transport via Ag colloids between the Ag bulk and the emitter. Thus, the transfer length as well as the specific contact resistance decreased. For more details a model of the current path was proposed to explain the effect of HF treatment at the edge of the Ag grid. It is expected that HF treatment may help to improve the contact of high sheet-resistance emitter as well as the contact of a high specific contact resistance.

• Applied Chemistry for Engineering
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• v.28 no.5
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• pp.501-505
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• 2017

Due to the rapid urbanization and increased population, there is an increase in airtight nature of buildings which causes serious indoor air pollution. Among several indoor air pollutants, volatile organic compounds (VOCs) emitted from paint are of major concern. Therefore, there is an urge for the development of environmental friendly paint products. In this wok, a natural wall paint (NWP) was prepared by utilizing a natural clay material "sericite" as a main component. A small chamber test was carried out to identify the toxic substances release from NWP and the results were compared with two eco-friendly commercial paints. The total VOCs were detected in trace level inside the test chamber and their concentrations were below the recommended indoor air quality standards. Toluene was not detected for NWP, whereas formaldehyde was observed in trace level. The toxicity index results were compared with two commercial paints and found that NWP exhibited less harmful gas emission. Based on certification rating of building materials, NWP can be classified as the first grade of building materials. Due to the above advantages, the use of sericite as a major component in NWP will be a useful technique to maintain the indoor air quality.