In this study, we measured the concentration of total volatile organic compounds (TVOCs) in four different seasons from 2016 to 2017 in order to determine seasonal variation of indoor air quality in relation to public transportation modes (subways, trains, and express buses). The measurement was carried out both during rush hour when traffic was congested as well as during non-rush hour when traffic was not congested. Effects by season, degree of congestion, and characteristics of public transportation were analyzed on the basis of 295 items of data during the periods of congestion and 295 items of data during the periods of non-congestion. The average TVOCs concentration in winter was the highest with 226.4 μg/m 3 . The average TVOCs concentration on an express bus was the highest with a seasonal average of 142.3 μg/m 3 . The TVOCs concentration in the period of congested traffic was higher than in the period of non-congested traffic for all public transportation modes. For the average TVOCs concentration by season and transportation, there was no data that exceeded the guidelines regarding maintaining indoor air quality. However, 2.5% of all sample measured data (TVOCs) exceeded the guidelines regarding maintaining indoor air quality. Therefore, the continuous monitoring of public transport vehicles is required.

This study was conducted to determine the absorption properties of silicone oil, liquid paraffin, and silicone rubber as absorbents for hydrophobic volatile organic compounds (VOCs) mainly emitted from the printing and publishing industry through VOCs absorption efficiency and partition coefficient. Also, changes in absorbability were tested through blending of absorbents and load of target VOCs mixtures. The results obtained can be used as fundamental data to choose an appropriate absorbent. All of the three absorbents showed an excellent absorption efficiency of above 98% for each 5 wt% load of the target VOCs including toluene, xylene, methyl ethyl ketone (MEK), isopropyl alcohol (IPA), 1,2,4-trimethylbenzene (124-TMB), and n-Nonane. In terms of toluene load, all absorbents showed good absorption efficiency of above 95% to a high load of 15 wt%. The air-absorbent partition coefficient of each target compound (P value) exhibited the highest value of 9.8 × 10−5 for 124-TMB in silicone rubber and the lowest value of 1.6 × 10−2 for IPA in liquid paraffin. These results indicate that the target VOCs had high affinity for the three absorbents. Absorption efficiency for the target VOCs at various absorbent blending ratios using three kinds of absorbents was improved to 99.9% regardless of the absorbent type or blending ratio. This result suggests that the shortcomings of single absorbents can be overcome through absorbent blending, enabling cost reduction and applicability to a dry-type treatment process. In treatment for mixture of the target VOCs to mimic an actual VOCs treatment, the absorption performances of silicone oil showed an absorption efficiency of 99% for 16 wt% of total VOCs load. These results indicated that silicone oil could be considered as a good absorbent.

A pilot-scale biocover was installed at a sanitary landfill for municipal waste, and the removal of volatile organic compounds (VOCs) by the biocover was evaluated for a long period of 550 days. The biocover (2.5 m W × 5 m L × 1 m H) was constructed with the mixture of soil, perlite, earthworm cast and compost (6:2:1:1, v/v). The total VOCs concentration of the inlet gas into the biocover was 820.3 ppb~7,217.9 ppb, and the total VOCs concentration of the outlet gas from the surface of the biocover was 12.6 ppb~1,270.1 ppb. The average removal efficiency of total VOCs was 87.6 ± 11.0% (60.5% for minimum and 98.5% for maximum). Toluene concentration was the highest among the inlet VOCs, followed by ethylbenzene, m, p-xylene and o-xylene. These aromatic VOCs accounted for more than 50% of the total VOCs concentration. Other than these aromatic VOCs, hexane, cyclohexane, heptane, benzene, and acetone were major VOCs among the inlet VOCs. Compared with the VOC profiles in the inlet gas, the relative contribution of dichloromethane to the outlet VOCs emitted from the biocover layer increased from 0.1% to 15.3%. The average removal efficiencies of BTEX in the biocover were over 84% during the operation period of 550 days. The average removal efficiencies of hexane, cyclohexane and heptane in the biocover were 86.0 ± 18.9%, 85.4 ± 20.4% and 97.1 ± 4.0%, respectively. The removal efficiency of VOCs in the biocover decreased not only when the ambient temperature had fallen below 5oC, but also when the ambient temperature had risen above 23oC. Information on the VOCs removal characteristics of the biocover installed in the landfill field can be useful for commercializing the biocover technology for the treatment of VOCs.

Volatile organic compounds(VOCs) are toxic carcinogenic compounds found in wastewater. VOCs require rapid removal because they are easily volatilized during wastewater treatment. Electrochemical advanced oxidation processes(EAOPs) are considered efficient for VOC removal, based on their fast and versatile anodic electrochemical oxidation of pollutants. Many studies have reported the efficiency of removal of various types of pollutants using different anodes, but few studies have examined volatilization of VOCs during EAOPs. This study examined the removal efficiency for VOCs (chloroform, benzene, trichloroethylene and toluene) by oxidization and volatilization under a static stirred, aerated condition and an EAOP to compare the volatility of each compound. The removal efficiency of the optimum anode was determined by comparing the smallest volatilization ratio and the largest oxidization ratio for four different dimensionally stable anodes(DSA): Pt/Ti, IrO2/Ti, IrO2/Ti, and IrO2-Ru-Pd/Ti. EAOP was operated under same current density (25 mA/cm2) and electrolyte concentration (0.05 M, as NaCl). The high volatility of the VOCs resulted in removal of more than 90% within 30 min under aerated conditions. For EAOP, the IrO2-Ru/Ti anode exhibited the highest VOC removal efficiency, at over 98% in 1 h, and the lowest VOC volatilization (less than 5%). Chloroform was the most recalcitrant VOC due to its high volatility and chemical stability, but it was oxidized 99.2% by IrO2-Ru/Ti, 90.2% by IrO2-Ru-Pd/Ti, 78% by IrO2/Ti, and 75.4% by Pt/Ti anodes The oxidation and volatilization ratios of the VOCs indicate that the IrO2-Ru/Ti anode has superior electrochemical properties for VOC treatment due to its rapid oxidation process and its prevention of bubbling and volatilization of VOCs.

In this study, volatile organic compounds (VOCs) emitted from printing industries were analyzed, and an inorganic adsorbent, γ-alumina, was selected for the effective control of the VOC emissions. Printing processes commonly require inks, thinners, and cleaners, and they were mixed organic solvents containing aromatic compounds, ketones, and alcohols. Therefore, toluene, methyl ethyl ketone (MEK), and isopropyl alcohol (IPA) were selected as model compounds for this study. The adsorptive properties using γ-alumina were determined for the model compounds. Both batch isotherm and continuous flow column tests demonstrated that the adsorption capacity of MEK and IPA was 3~4 times higher than that of toluene. The column test performed at an inlet toluene concentration of 100 ppm showed that an 80% breakthrough for toluene was observed after 3 hours, but both MEK and IPA were continuously adsorbed during the same time period. A numerical model simulated that the γ-alumina could remove toluene at a loading rate of 0.4 mg/min only for a 4-hour period, which might be too short of a duration for real applications. Consequently, lifetime enhancement for γ-alumina must be implemented, and ozone oxidation and regeneration would be feasible options.

Indoor Volatile organic compounds (VOCs) are classified as known or possible toxicants and odorants. This study characterized VOC levels in 11 homes in an area in the capital of Seoul by using two different methods of VOCs sampling, which are the active sampling using a thermal sorption tube and the passive sampling using a diffusion sampler. When using the active sampling method, the total target VOC concentration ranged from 41.7 to 420.7 μg/ m3 (mean 230.4 μg/m3; median 221.8 μg/m3) during winter and 21.3 to 1,431.9 μg/m3 (mean 340.1 μg/m3; median 175.4 μg/m3) during summer. When using the passive method, 29.6 to 257.5 μg/m3 (mean 81.8 μg/m3; median 49.4 μg/m3) during winter and 1.2 to 5,131.1 μg/m3 (mean 1,758.8 μg/m3; median 1,375.1 μg/m3) during summer. Forty-nine VOCs were quantified and toluene showed the highest concentration regardless of the season and the sampling method studied. The distribution of VOCs was relatively varied by using the active method. However, it showed a low correlation with indoor environmental factors such as room temperature, humidity and ventilation time. The correlation between indoor environmental factors and VOCs were relatively high in the passive method. In particular, these characteristics were confirmed by principal component analysis.

Two sewage treatment facilities were selected to identify odor emission characteristics, focusing on volatile organic compounds (VOCs) and sulfur compounds. The complex odor, 5 kinds of sulfur compounds and 23 kinds of VOCs were analyzed from gas and sludge storages. Hydrogen sulfide was detected in the highest concentration and had the highest odor quotient among the odorous compounds monitored in this study, demonstrating that the contribution of hydrogen sulfide to the complex odor reached up to 90%. For VOCs, the overall contribution to the complex odor was not critical but VOCs can sufficiently trigger an odorous sensation because the sum of the odor quotient reached up to 2.89.

This paper is a review on the treatment of volatile organic compounds using absorbents. Volatile organic compounds (VOCs) are carbon-based compounds with a boiling point ranging from 50℃ to 250℃. VOCs have been considered as contributors of photochemical smog and global warming as well as hazards to human health. VOCs can be removed by a variety of methods, including those that are destructive (incineration, catalytic oxidation, and biodegradation) and non-destructive (adsorption, absorption, and condensation). The removal performance of VOCs in the gas phase is influenced by gas-liquid mass transfer and/or the microbial activity depending on VOC properties such as solubility, diffusivity, bioavailability, and toxicity. Since the usual processes for VOCs removal involve water as a VOC absorbent, it is necessary to improve the removal efficiency of hydrophobic VOCs. In addition, VOC removal processes do not appear to show consistently satisfactory performance due to transient high-strength VOC loading in practical fields. To increase the gas-liquid mass transfer of hydrophobic VOCs and to prevent the functional deterioration due to transient high loading, the use of nonaqueous phase VOC absorbents is a promising strategy. This review offers a critical overview of the types, properties, and the applications of the VOC absorbents, including liquid organic solvents, ionic liquids, and solid polymers. This paper also details the advantages by employing the VOC absorbents for the removal of hydrophobic VOCs in the integrated process, absorption and biodegradation coupling process. The challenges of and future perspectives on the development of efficient VOC removal processes using VOC absorbents are briefly discussed.

The aim of this study was to examine indoor fungal concentration and fungal volatile organic compounds(VOCs) in single-person households. A total of 22 houses occupied by one person were investigated in this study. 19 VOCs detected in the field were estimated as fungi-derived VOCs through a review of the literature, and 11 VOCs were confirmed as fungal VOCs by laboratory experiments. Exposure to fungal VOCs in the indoor environment has been confirmed to be highly influenced by airborne fungal concentration and indoor humidity. 3-octanone was characterized by a clear generation profile in Aspergilus versiocolor, and n-decane in Pencillum chrysogenum. ntetradecane emitted by Stachybotrys chartarum exhibited a tendency to occur consistently. The observations made in this study demonstrated that single-person households can easily be exposed to fungi, and MVOCs can be used as an indicator of fungal exposure in indoor environments.

There has been growing concern over the emissions of formaldehyde and VOCs from automotive interior materials, as these could have an important impact on the in-vehicle air quality (IVAQ) of automotive vehicles. Odor along with VOCs refers to the automotive interior smell emitted directly or indirectly from any part of an automotive interior, based on human olfactory senses and a comfort evaluation of vehicle quality. The objective of this paper is to compare the odor intensity using GC/MS analysis method and odor sensory test in accordance with ISO 12219-2. For the compounds having low odor threshold value and high VOC concentration, it was found that there was the same tendency in each field of odor whether the instrument analysis method or the odor sensory test method was used.

Per capita nail-products use and airborne VOCs emission in four techniques of nail care (full coat coloring, UVgel polish, repair silk, and acrylic overlay) are estimated in this study. These assessments were carried out in a sealed test chamber using artificial hand and nails. A polish remover and a gel cleanser as cleanser and acrylic liquid as solvent were the most commonly used nail products in all 4 of the nail care techniques. Acetone, isopropyl alcohol, and methanol, which are major components of a polish remover, were commonly detected in all nail care techniques while acetone was detected the most. In addition to these airborne VOCs, a variety of other components such as ethyl acetate, cyclohexane, and toluene were identified in full coat coloring technique. In the process of UV-gel polish care technique, the main airborne VOCs were caused by solvents and were not involved in the curing process of UV gels (base gel and top gel) and gel bonder. In the case of repair silk nail care techniques, which generated the most VOCs, the total amount of VOCs detected was about 1,118.8 ± 359.6 mg/capita. Of the VOCs, butane (862.2 ± 283.9 mg/capita), which is contained in glue dryer, represented the largest share. In the process of acrylic overlay nail care technique, ethyl methacrylate (EMA), which is the basic element of acrylic, and highly toxic methyl methacrylate (MMA) were detected at 396.6 ± 42.3 mg/capita and 141.8 ± 8.2 mg/capita, respectively. The per capita data is very useful in designing a ventilation system for environmental improvement of a nail shop and setting a health care policy for nail artists and customers.

The consumer products in the living environments include a variety of chemicals which could be harmful in the human health. The aim of this study was to assess the inhalation exposure and risk for cleaning workers who had used bleach in the university. A total of 81 cleaning workers took part in this study. Frequency and amount of cleaning bleach during working hours were investigated by questionnaire interviews. Exposure assessment was used by the exposure algorithm and exposure factors. Used cleaning bleaches were analyzed to identify the ingredients, and risk by exposure was assessed by separating as carcinogen and non-carcinogen substances. The results of chemical substances and the questionnaire were used to assess the exposure factors, and the inhalation doses were calculated through inhalation exposure algorithm. According to the questionnaires for the cleaning workers, frequence of cleaning bleach was 11.66 ± 7.21 times per month. And average usage time and amount per cleaning work were 30.78 ± 36.00 minute and 20099.53 ± 12998.60 mg, respectively. Risks for carcinogenic substances of formaldehyde, ethylbenzene, and chloroform were exceeded by 56.79%, 27.16%, and 82.72% as the reference value of 10−6, respectively.

In order to use as a new functional food material, we analyzed the chemical components including the organic compounds, minerals and Vitamin C of sorbus and acacia honey which were produced in South Korea. The condensed rate of methanol extraction in honey was 77% of sorbus honey and it was 93.06% of acacia honey. In the case of sorbus honey, main organic compounds that extract by organic solvents in GC-MS analysis were trichloromethane, propylcarbinol, cyclopentane, acetoxyethane, tetrasol, aziridine etc. and main aromatic compounds that extract by organic solvents in SPME analysis were Skelly solve, Benzaldehyde, Hyacinthin, Dodecanal, Lauraldehyde etc. Also, in occasion of acacia honey, main organic compounds were trichloromethan, Acetoxyethane, Hexanaphthene, acetidin etc. and main aromatic compounds were Hydrazomethan, Azulene, Cyclotrisiloxane, Hydrazine etc. Proximate composition was crude protein 0.54%, crude fat 0.44%, crude ash 0.25% in sorbus honey and crude protein 0.10%, crude fat 0.29%, crude ash 0.06% in acacia honey. Free sugar that analyze by HPLC was fructose 26.81%, glucose 20.42%, total sugars 47.23% in sorbus honey and fructose 48.52%, glucose 24.29%, total sugars 72.81% in acacia honey. Vitamin C was not detected in two sample honeys. Minerals by ICP analysis were detected total 18 kinds in sorbus honey, K 11.715 ppm>Na 7.857 ppm>Si 4.407 ppm>Ca 3.673 ppm etc. and total 22 kinds in acacia honey, Na 4.527 ppm>Si 3.420 ppm>K 3.091 ppm>Zn 1.482 ppm etc.

In order to use as a new functional food material, we analyzed the chemical components including the organic compounds, minerals and vitamin C of canola honey which were produced in South Korea. The condensed rate of methanol extraction in honey was 90.5% and main organic compounds that extract by organic solvents in GC-MS analysis were propyl carbinol, cyclopentane, trichloromethane, vinegar naphtha and so on. Also, main aromatic compounds that extract by organic solvents in SPME analysis were diisooctyl adipate, furole, furaldehyde, cyclotetrasiloxane, trisulfide and many more. As proximate composition, crude ash content was lower than acacia honey (0.06%) and manuka honey (0.24%) by 0.01%, and crude protein was higher than acacia honey (0.10%) by 0.23%, but the crude fat of canola and manuka honey was lower content than acacia honey (0.44%) by 0.10%. Free sugar that analyze by HPLC consisted of fructose 44.11%, glucose 22.72%, and total sugars was 66.83%. Minerals by ICP analysis were detected total 15 kinds, Na 7.157 ppm>Ca 5.934 ppm>Si 4.049 ppm>K 1.443 ppm>Mg 1.218 ppm etc. Vitamin C was not detected.

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.

본 연구는 감꽃의 주요 향기성분을 알아보기 위해서 감나무 수령별로 감꽃의 향기성분을 SPME를 이용하여 분석하고, 기관을 꽃과 꽃받침으로 분류하여 향기성분을 비교하였다. 감나무 수령별 감꽃의 만개율은 15년생 이상, 10-14년생, 5-9년생 순으로 수령이 오래될수록 초기 만개율이 높았다. 감나무 수령에 따른 감꽃 향기성분 분석 시 동정된 주요 향기 성분은 a-pinene, butene, caryophyllene, cubebene, lavandulol, D-limoneneylangene, ylangene 등의 성분을 얻을 수 있었다. 대부분이 green 향, fruit계, floral계의 옅은 향도 포함하고 있었다. 감꽃에 존재하는 휘발성 향기성분의 수는 5-9년생은 30종, 10-14년생은 24종, 그리고 15년생 이상에서는 32종으로 수령이 5년 미만과 15년 이상에서 많은 향기성분이 조사되었다. 감꽃을 꽃받침과 나누어 향기성분을 비교하면 단감 ‘부유’ 품종 중 꽃의 향기 성분은 10개이고 상대적인 총 함량은 26.35%이며, 꽃받침은 향기 성분은 14개 이고 상대적인 총 함량은 46.28%로 꽃에 비해서 더 다양한 향기성분이 존재하는 것으로 조사되었다. 반면 떫 은감 ‘둥시’ 품종은 꽃에서는 6개의 향기성분이 17.58%, 꽃받침에서는 9개의 향기 성분이 50.27%로, ‘부유’ 품종 에 좀더 다양한 향기성분이 존재하였다. 본 연구는 감꽃 향기를 이용하고자 하는 향기산업에 기초자료를 제공하 는데 기여할 것이다.

Volatile organic compounds(VOCs) detected frequently in the indoor air of child-care centers causes neurological disorders, lung, eyes, and bronchial irritation, and acute and chronic toxicity. In this study, the distributions of carcinogenic VOCs detected in child-care centers were characterized and a health risk assessment of the VOCs was performed, which can provide the necessary information for drawing up safety plans with respect to the concerned materials. The sampling of sites in day-care centers was undertaken two times: in the morning (10:00~12:00), and afternoon(16:00~20:00)-at 23 daycare centers located in Seoul, Korea from April, 2012 to July, 2012. The overall average concentrations of individual VOCs were benzene(1.61 μg/m3) > carbon tetrachloride (0.78 μg/m3) > chloroform(0.67 μg/m3) in order. Indoor/outdoor(I/O) ratios of benzene, carbon tetrachloride, chloroform were 1.33, 1.09, 1.72, respectively. Benzene and carbon tetrachloride are thought to be more strongly associated with outdoor sources as compared to chloroform. Spearman correlation of benzene, carbon tetrachloride between indoor and outdoor concentration showed statistically significant levels(p < 0.05). The linear correlations for benzene, styrene, and carbon tetrachloride were tested. A significant correlation was observed only for carbon tetrachloride, accounting for 83 % of the variance. The risk assessment of the carcinogenic VOCs for teachers, infants, and children showed that none of the targeted VOCs posed a serious risk.