• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1161-1169
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• 2008

The removals of TCE and PCE vapor with or without a supply of toluene as a primary substrate were compared in a biofiltration process, and the variations of microbial communities associated with the removal were also investigated. As a result of investigations on the removals of TCE/PCE in a biofilter B within which TCE/PCE-acclimated sludge was attached on the surface of media without a supply of primary substrate, and those in another biofilter A where toluene-acclimated sludge was attached with a supply of toluene as a primary substrate, followings were found: (i) parts of microbes responsible to the decomposition of toluene vapor participate in the removal of chlorinated VOCs such as TCE and PCE, and (ii) effective biological removals of TCE and PCE vapor do not necessarily need cometabolism. Sequencing of 16S rDNA obtained from the band profile of DGGE (Denaturating Gradient Gel Electrophoresis), it was confirmed that: (i) uncultured alpha proteobacterium, uncultured Desulfitobacterium, uncultured Rhodobacteraceae bacterium, Cupriavidus necator, and Pseudomonas putida were found to be toluene-decomposing microbes, (ii) alpha proteobacterium HTCC396 is a TCE-removing microbe, (iii) Desulfitobacterium sp. is a PCE-decomposing microbe, and (iv) particularly, uncultured Desulfitobacterium sp. is probably a microbe decomposable not only toluene but also various chlorinated VOC vapor including TCE and PCE.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.65-72
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• 2007

The VOC (volatile organic compound) analyzer is devised to measure the four main aromatic hydrocarbon gases: toluene, ethylbenzene, xylene and styfene. It is not affected by ambient temperature and humidity. In addition, standby and measuring time of VOC Analyzer is a short as below 30 min and 8 min, respectively. Since the semiconductor gas sensor is supersensitive to gas components, it is not necessary to use a conventional gas concentrator or other complicated equipment. In this study, VOC emission behavior from 4 types paints (lacquer, urethane vanish, water-base paint, enamel paint) for wood-based panel was investigated using VOC Analyzer. After a specimen was spreaded on aluminum foil ($6.32{\times}6.32cm$) in $3{\ell}$ polyester bag, after 24 hours we could measure maximum VOC emission level that is a stabilized VOC value. Xylene of VOCs was high emitted from lacquer, urethane vanish and water-based paint, and TVOC (Toluene + Ethylbenzene + Xylene + Styrene) of lacquer was the highest emission concentration than another.

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.519-525
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• 2008

Biodegradation of toluene, styrene and hydrogen sulfide as model compounds of volatile organic compounds and odor from waste gas was investigated experimentally in a biotrickling filter. This study focussed on the description of experimental results with regard to operating conditions. The effect of varying $H_2S$ load rate and inlet concentration was investigated under autotropic and mixotropic environmental conditions. The $H_2S$ removal efficiencies of greater than 99% were achieved at $H_2S$ loads below $10g/m^3{\cdot}hr$ for each environment. It was observed that the maximum elimination capacity of mixotrophic filter was achieved a little greater than the one of autotrophic filter. The biofiltration of toluene and styrene in trickling bed was examined under different gas flow rates, load rates, and inlet concentrations. Below $40g/m^3{\cdot}hr$ of toluene loading, the elimination capacity and loading were identical and it was completely destroyed. In high loading of toluene, the biotrickling filter was operated at its maximum elimination capacity. In the inlet concentration of 0.2, 0.5, and $1.0g/m^3$, the maximum elimination capacity of toluene showed 40, 45, and $60g/m^3{\cdot}hr$, respectively. After a short adaptation period, it was demonstrated that the results of styrene in originally toluene adapted bioreactor was similar with the ones of toluene. However, the performance of filer for styrene is generally a little lower than for toluene. The operating conditions (including liquid flow rate etc.) allowing the highest removal efficiency should be determined experimentally for each specific case.

• Journal of Environmental Health Sciences
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• v.49 no.6
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• pp.344-352
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• 2023

Background: With its developed port and related industries, the concentration of fine dust is high in Busan compared to other cities in South Korea. Many studies have reported the health effects of fine dust, but there has been a lack of information regarding concentrations of volatile organic compounds among those who exposed to high levels of fine dust. Objectives: This study aimed to define an area with high concentrations of particulate matter and perform biomonitoring surveys among the residents of the area. Methods: Air quality data was collected and the mean level of each district in Busan was derived. We then defined the area with the highest concentrations of PM₁₀ as a target site. Urine samples were collected from the 400 participants and analyzed for VOCs metabolites - trans,trans-Muconic Acid (t,t-MA) and N-AcetylS-(benzyl)-L-cysteine (BMA). Interviews were conducted by trained investigators to examine demographic information. The levels of t,t-MA and BMA were compared with representative South Korean population data (Korean National Environmental Health Survey). The association of the VOC metabolites and fine dust were analyzed by general linear regression analysis. Results: The mean of PM₁₀ in the target site was 42.50 ㎍/m³ from 2018 to 2020. Among the 400 participants in the target site, 74.8% were female and the average age of the participants was 66 years. The geometric mean of t,t-MA was 71.15 ㎍/g creatinine and the BMA was 7.00 ㎍/g creatinine among the residents. The levels were higher than the geometric mean from the 4th KoNEHS. The levels of t,t-MA showed significance in BMI, smoking status, and household income. BMA showed significance in gender and age. Conclusions: Compared to the general population of South Korea, the target site's residents had higher biomonitoring levels. Based on this study, continuous screening for high risk areas, including the target site, and biomonitoring of the residents are required.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.5
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• pp.536-546
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• 2016

The diurnal variations of $O_3$ and $NO_2$ in an urban park and the effects of air temperature and wind speed on the diurnal variations are investigated. $O_3$ and $NO_2$ concentrations were observed at a site in an urban park of Seoul from 27 July 2015 to 9 August 2015. The $O_3$ and $NO_2$ concentrations observed in the urban park are compared to those observed at the Gangnam air quality monitoring station (AQMS). The $O_3$ concentration is higher in the urban park than at the Gangnam AQMS in the daytime because the amount of $O_3$ dissociated by NO is smaller as well as partly because the amount of $O_3$ produced in the oxidation process of biogenic volatile organic compounds (VOCs) is larger in the urban park than at the Gangnam AQMS. The $NO_2$ concentration is lower in the urban park than at the Gangnam AQMS during day and night because the observation site in the urban park is relatively far from roads where $NO_x$ is freshly emitted from vehicles. The difference in $NO_2$ concentration is larger in the daytime than in the nighttime. To examine the effects of air temperature and wind speed on the diurnal variations of $O_3$ and $NO_2$, the observed $O_3$ and $NO_2$ concentrations are classified into high or low air temperature and high or low wind speed days. The high $O_3$ and $NO_2$ concentrations in the daytime appear for the high air temperature and low wind speed days. This is because the daytime photochemical processes are favorable when the air temperature is high and the wind speed is low. The scatter plots of the daytime maximum $O_3$ and minimum $NO_2$ concentrations versus the daytime averages of air temperature and wind speed show that the daytime maximum $O_3$ and minimum $NO_2$ concentrations tend to increase as the air temperature increases or the wind speed decreases. The daytime maximum $O_3$ concentration is more sensitive to the changes in air temperature and wind speed in the urban park than at the Gangnam AQMS.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.807-810
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• 2011

The sensor network technology for core technology of ubiquitous computing is in the spotlight recently, the research on sensor network is proceeding actively which is composed many different sensor node. USN(Ubiquitous Sensor Network) is the network that widely applies for life of human being. It works out to sense, storage, process, deliver every kind of appliances and environmental information from the stucktags and sensors. And it is possible to utilize to measure and monitor about the place of environmental pollution which is difficult for human to install. It's studied constantly since it be able to compose easily more subminiature, low-power, low-cost than previous one. And also it spotlights an important field of study, graft the green IT and IT of which the environment and IT unite stragically onto the Network. The problem for the air pollution in the office or the indoor except a specific working area is the continuously issue since the human beings have lived in the dwelling facilities. Measures for that problem are urgently needed. It's possible to solve for the freshair of outside with enough ventilation but that is the awkward situation to be managed by person. This study is the system engineering to management for indoor air condition under the sensor network. And research for efficiently manage an option.

• Analytical Science and Technology
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• v.22 no.3
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• pp.191-200
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• 2009

The aim of this study was to evaluate and establish of emission test method for liquid phase building materials such as paint, adhesive, sealant by emission cell. A small-scale emission chamber and emission cell were used to evaluate emission of TVOC from paint, adhesive, sealant. The quantity of TVOC emission were measured by a gas chromatography/mass spectrometry (GC/MS). Background concentration of TVOC was below $10{\mu}g/m^3$ in the emission chamber and cell. Air tightness and recovery in chamber and cell showed good results. The recovery of thermal desorber for toluene and n-dodecane were about 120%. The repeatability of response factor and retention time in GC/MS below 30%. The method detection limit of VOCs ranged 0.04~8.82 ng. The concentration of TVOC emission using emission cell was 1.35~1.41 times higher than emission chamber. The correlation of TVOC emission using chamber and cell method was significantly high (r=0.91~0.97).

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.3
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• pp.251-260
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• 2014

Biomass burning is one of the significant emission source of PM and CO, but a few studies are reported in Korea. Air pollutants emission from biomass burning such as wood stove and boiler, and wood-pellet stove and boiler were estimated in this study. Activity levels related to biomass burning such as fuel types, amount of fuel loading, and location and temporal variation were investigated by field survey over Korea. Fuel loadings were 14.9 kg/day for wood stove, 31.3 kg/day for wood boiler, 12.8 kg/day for wood-pellet stove, 32.5 kg/day for wood-pellet boiler during the season of active use. These were mostly burned in winter season from october to april of next year. Estimated annual emissions from wood stove & boiler were CO 76,677, $NO_x$ 710, $SO_x$ 70, VOC 20,941, TSP 6,605, PM10 2,921, PM2.5 1,851, and NH3 7 ton/yr, respectively. Emissions from wood-pellet stove and boiler were CO 32,798, $NO_x$ 1,830, $SO_x$ 25, VOCs 5,673, TSP 629, PM10 457, PM2.5 344, and $NH_3$ 2 ton/yr, respectively. When the emission estimates are compared with total emissions of the national emission inventory (CAPSS: Clean Air Policy Support System), Those occupy 12.5%, 2.8% of total national emission for CO and PM10, respectively. These results show wood and wood-pellet burning appliances were one of the major source of air pollution in Korea. In future, these types of heaters need to be regulated to reduce air pollution, especially in suburb area.

• Journal of the Korean Wood Science and Technology
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• v.35 no.5
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• pp.58-66
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• 2007

The objective of this research was to develop environment-friendly adhesives for face fancy veneer bonding of engineered flooring. Urea-formaldehyde (UF)-tannin and melamine-formaldehyde (MF)/PVAc hybrid resin were used to replace UF resin in the formaldehyde-based resin system in order to reduce formaldehyde and volatile organic compound (VOC) emissions from the adhesives used between plywoods and fancy veneers. Wattle tannin powder (5 wt%) was added to UF resin and PVAc (30 wt%) to MF resin. These adhesive systems showed better bonding than commercial UF resin with a similar level of wood penetration. The initial adhesion strength was sufficient to be maintained within the optimum initial tack range. The standard formaldehyde emission test (desiccator method) and VOC analyzer were used to determine the formaldehyde and VOC emissions from engineered flooring bonded with commercial UF resin, UF-tannin and MF/PVAc hybrid resin. By desiccator method, the formaldehyde emission level of UF resin showed the highest but was reduced by replacing with UF-tannin and MF/PVAc hybrid resin. MF/PVAc hybrid satisfied the $E_1$ grade (below $1.5mg/{\ell}$). VOC emission results by VOC analyzer were similar with the formaldehyde emission results. TVOC emission was in the following order: UF > UF-tannin > MF/PVAc hybrid resin.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.1
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• pp.169-177
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• 2006

In this study, it was studied that the removal rate of VOC by the catalytic combustion. The combustion temperature was changed by the contact type of VOC(space velocity and catalyst depth) and the space velocity(SV) was defined by the rate of gas volume flow rate(Q, $m^3/hr$) over volume(V, $m^3$) of catalyst (SV=Q/V). The space velocity of catalytic combustor is maintained $10,000{\sim}50,000hr^{-1}$. it was studied that the conversion rate of VOC by the catalytic combustion. The combustion temperature was changed by the contact type of VOC and catalyst and the space velocity was defined by the rate of gas volume flow rate over volume of catalyst. The VOC which pass thru the heat exchanger was measured by the hydro ionic detector and measured the VOC removal rate by the activated catalyst in the reaction temperature range of 373K-423K. The removal rate was measured over 100 times. In the automobile painting booth The VOC concentration was 63.37ppm and the removal rate was 70 % at 373K and 78.92% at 423K. The removal rate was increased as increased the temperature.