• Asian Journal of Atmospheric Environment
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• v.4 no.2
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• pp.63-71
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• 2010

The removal characteristics for aromatic and aliphatic VOCs by electron beam (EB) were discussed in terms of several removal variables such as initial VOC concentration, absorbed dose, background gas, moisture content, reactor material and inlet temperature. It was reviewed that only reactor material was an independent variable among the potential control factors concerned. It was also suggested that main mechanism by EB should be radical reaction for the VOC removal rather than that by primary electrons. It was discussed that the removal efficiency of benzene was lower than that of hexane due to a closed benzene ring. In the case of aromatic VOCs, it was observed that the decomposition of the VOCs with more functional groups attached on the benzene ring was much easier than those with less ones. As for aliphatic VOCs, it was also implied that the longer carbon chain was, the higher the removal efficiency became. An EB-catalyst hybrid system was discussed as an alternative way to remove VOCs more effectively than EB-only system due to much less by-products. This hybrid included supporting materials such as cordierite, Y-zeolite, and $\gamma$-alumina.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.100-107
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• 2001

On the planning for the systematic management and control of the air pollution display methods were used to evaluate the spatial pollutant concentration status. This study were conducted to investigate the practical using of Geographic Information System(GIS) technology on the air pollution control and management which were computer-based systems that were used to store and manipulate geographic information in the macro city. In this study 137 samples were corrected by passive samplers and analysed by GC/MSD for 16 VOCs in Seoul (25 distincts) distributed by TM-coordinate(2 km$\times$2km), and finally displayed by Arciew program(version 3.2, ESRI Inc, USA) for windows. The concentration of benzene and toluene showed high level in whole area of seoul area of Seoul and distribution of butylbenzen, trothroloetylene, stylen showed high level in whole area of Seoul except a few distincts and the distribution of isopropylbenzene, 1,2-dichroloethane showed higher level in core area than that of Kangnam and Kangbuk area. In conclusion, products of this study of using GIS technology apply on the spatial distribution of VOCs concentration was very effective than that of other methods(e.g., contouring concentration method, pie or column chart, graduated symbols), especially in mapping and symbolization of pollution status evaluation.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.139-141
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• 2004

Emission of volatile organic compounds (VOCs) are one of the popular issues of air pollution in Korea, especially in Ulsan city, where much chemical plants are located. It is necessary to detect the VOCs precisely in order to control the air pollution during the plant operation. In general, to examine the concentration of VOCs, gas chromatography (GC) is used. However, most plant operators are using the easy operating handy VOCs detector, which is imported, because GC is difficult to treat and the installation price is high although it is very useful equipment. Therefore, the development of the VOCs detector becomes one of the urgent issues. In this study, sensing characteristics of selected VOCs for the development of VOCs detector was investigated. Semiconductor sensor and several VOCs such as aliphatic, aromatic, and non-homogeneous hydrocarbons were used for the experiment. Through the various experiments, sensor used in the experiment has shown high linearity and sensitivity for most VOCs in the range of 1 -500 ppm concentration.

• Journal of Environmental Impact Assessment
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• v.10 no.2
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• pp.135-145
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• 2001

This study was conducted to investigate the practical using of Geographic Information System(GIS) technology which are computer-based systems that are used to store and manipulate geographic information on the air pollution control and management in the macro city. For this study 130 samples were corrected by passive sampler in Seoul (25 distincts) distributed by TM-coordinate during November in 1997 to January 1998, and analysed by GC/MSD for 16 VOCs e.g., toluene, benzene and display using Arc/view GIS(version 3.2, ESRI Inc, U.S.A) for windows. The most VOCs concentration distribution in November, 1997 was higher than that of January, 1998 except benzene and 1,1,2-trichroloethan, bromobenzene. And products of the distribution of VOCs concentration display using GIS technology was effective as well as other display methods(e.g., contouring method, pie or column chart, graduated symbols), especially in mapping and symbolization capabilities for spatial pollutant status evaluation were very effective than other display methods.

• Analytical Science and Technology
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• v.34 no.5
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• pp.202-211
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• 2021

Volatile organic compounds (VOCs) in hazardous air pollutants (HAPs) have been regulated by the Air Pollution Control Act (1978) and their atmospheric concentrations have been monitored in 39 monitor sites in Korea. However, measurement standards of volatile organic compounds (VOCs) in HAPs at ambient levels have not been established in Korea. Primary reference gas mixtures (measurement standards) at ambient levels are required for accurately monitoring atmospheric VOCs in HAPs and managing their emissions. In this study, primary reference gas mixtures (PRMs) at 5 nmol/mol were developed in order to establish primary national standards of VOCs in HAPs at ambient levels. Primary reference gas mixtures (PRMs) were prepared in pressurized aluminum cylinders with special internal surface treatment using gravimetric method. Analytical methods using gas chromatography-flame ionization detector (GC-FID) coupled with a cryogenic preconcentrator were also developed to verify the consistency of gravimetrically prepared HAP VOCs PRMs. Three different columns installed in the GC-FID were evaluated and compared for the retention times and separation of eighteen target components in a chromatogram. Results show that the HAP VOCs PRMs at 5 nmol/mol were consistent within a relative expanded uncertainty (k=2) of less than 3 % except acrylonitrile (less than 6 %) and the 18 VOCs were stable for 1 year within their associated uncertainties.

• Environmental Engineering Research
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• v.23 no.4
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• pp.397-405
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• 2018

As regulations governing the control of volatile organic compounds (VOCs) have become increasingly stringent in China, regenerative thermal oxidizers (RTOs) have been more frequently applied in medium- and high-concentration VOCs treatments. However, due to the lack of existing RTO-related research, experience remains a dominant factor for industrial application. This paper thus aimed to establish a model for industrial RTOs, using a transient simulation method and thermal equilibrium model to simulate the internal velocities and temperature distributions of an RTO across multiple cycles. A comparison showed an error of less than 5% between most correlating simulated and experimental measurement points, verifying that the simulation method was accurate. After verification, the velocity and temperature fields inside the RTO were simulated to study the uniformity of temperature and velocity within the packed beds: both fields displayed high uniformity after gas flowed through the honeycomb regenerator. The effects of air volume, VOCs concentrations, and valve switching times on the oxidation chamber temperature, RTO outlet temperature, and thermal efficiency (as well as their averages) were studied. The VOCs removal rate in this study was constantly above 98%, and the average thermal efficiency reached 90%.

• Journal of People, Plants, and Environment
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• v.22 no.1
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• pp.31-38
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• 2019

Experiments were carried out to investigate the effects of mosses on the removal of particulate matter (PM 10) and volatile organic compounds (VOCs) in an indoor space and on the composition of air. For particulate matter removal experiments, 0.2 g mosquitto coil was burned in a glass chamber, where three kinds of mosses (Plagiomnium cuspidatum, Myuroclada maximowiczii, Etodon luridus) were placed. For VOCs removal experiments, 1 mL paint thinner was volatilized in a glass chamber, where Plagiomnium cuspidatum and Myuroclada maximowiczii were used. As a result, it was found that particulate matter was effectively removed by the three mosses, and the removal efficiency of particulate matter increased as the amount of mosses increased. The amount of VOCs was similar to the level in the control when a low amount of mosses (2 and 4 plates) was used. However, the removal efficiency of VOCs was significant when 6 plates of mosses were used. On the other hand, formaldehyde concentration was 40 times more than the control and carbon monoxide 30 times, when 0.2 g of mosquito repellent was completely burned in a glass chamber. Also formaldehyde removal effect was significant when 6 plates of mosses were placed. However, there was no change in the concentration of indoor oxygen, temperature and humidity by moss plants. In conclusion, the moss plants were effective in removing particulate matter and VOCs, and they are expected to be used for indoor decoration and landscape in order to improve indoor air quality in the future.

• Journal of environmental and Sanitary engineering
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• v.16 no.4
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• pp.69-76
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• 2001

The catalytic oxidation of volatile organic compounds (VOCs), which were benzene and toluene, was studied in the supercritical carbon dioxide($SC-CO_2$) media. In $SC-CO_2$ media, the deep oxidation conversion of VOCs was increased with the temperature and pressure. The deep oxidation conversion in SC -$CO_2$ media is better than that in air media at same pressure condition. This can be explained by the solubility of VOCs in $SC-CO_2$. The many intermediates produced by the partial oxidation of VOCs were detected from off-line samples. The intermediates were Identified as benzene, toluene, benzaldehyde, phenol, naphthalene, 1,1`-biphenyl, benzoic acid, 3-methylphenol, 1,1'-(1,2-ethanediyl)bis- benzene, 1,1'-(1,2-ethene- diyl)bis-benzene, anthracene, and so on. The amount of intermediates was decreased as the molar radio of oxygen to carbon dioxide was decreased. When the molar ratio of oxygen to carbon dioxide was 1 : 16, the deep conversion was kept constant. Thus, the catalytic oxidation process in $SC-CO_2$ media can be combined on-line with supercritical fluid extraction of environmental matrices and supercritical regeneration of used adsorbent. Thus, the nontoxic $SC-CO_2$ media process was suggested as the new VOCs control technology.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.6
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• pp.397-405
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• 2012

In this study, performance evaluation of newly developed technology for the economical and safe removal of volatile organic compounds (VOCs) coming out from electronic devices washing operation and offensive odor induction materials was made. Metal oxidization catalyst has shown 50% of removal efficiency at the temperature of $220^{\circ}C$. Composite metal oxidization catalyst applied in this study has shown that the actual catalysis has started at the temperature of $100^{\circ}C$. Comprehensive analysis on the catalyst property using Mn-Cu metal oxidization catalyst in the pilot-scale unit was made and the removal efficiency was variable with temperature and space velocity. Full-scale unit developed based on the pilot-scale unit operation has shown 95% of removal efficiency at the temperature of $160^{\circ}C$. Optimum elimination effective rates for the space velocity was found to be $6,000hr^{-1}$. The most appropriate processing treatment range for the inflow concentration of VOCs was between 200 ppm to 4,000 ppm. Catalyst control temperature showed high destruction efficiency at $150{\sim}200^{\circ}C$ degrees Celsius in 90~99%. External heat source was not necessary due to the self-heat reaction incase of VOCs inflow concentration is more than 1,000 ppm. Equipment and fuel costs compared to the conventional RTO/RCO method can be reduced by 50% and 75% respectively. And it was checked when there was poisoning for sulfide and acid gas.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.1
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• pp.101-112
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• 2003

Biological methods are frequently used for treatment of contaminated air, containing volatile organic compounds and odor compounds in low concentrations and high flow rate of air streams. For more than 20 years. biofilter has been recognized as a cost effective technology for the purification of contaminated air. Most commercial applications before 1990 were for control of odors. In the past decades major progress has been accomplished in the development of vapor phase bioreactor. in particular biotrickling filers. Biotrickling filters are more complex than biofilters. but are usually more effective, especially for the treatment of compounds which are difficult to degrade or compounds that generate acidic by-products. While the level of understanding of biotrickling filtration process for VOCs still remains limited. the evidence success of biotreatment of VOC in air resulted in pursuing active research. This paper presents fundamental and practical aspert of VOCs treatment from air in biotrickling filter. Special emphasis is given to the operating parameters and the factors influencing performance for biotrickling filter.