• Land and Housing Review
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• v.6 no.4
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• pp.231-237
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• 2015

Recently, It has been much interest in modular housing construction. so, The purpose of this study was to investigate the characteristics of the indoor air quality in modular mock-up housing. We measured indoor air quality(formaldehyde, benzene, toluene, ethylbenzene, xylene, styrene) of two modular mock-up units that built-in furniture is installed and uninstalled. As a result, the pollutants of built-in furniture installed unit were emitted more than built-in furniture uninstalled unit. But after bake-out and ventilation, emission concentrations of two modular mock-up units were similar and were below Indoor Air Quality recommendation standards. Built-in furniture is likely to affect the emission concentration of toluene

• Journal of ILASS-Korea
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• v.23 no.4
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• pp.175-184
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• 2018

Emission characteristics of regulated (NOx, PM, CO, NMHC) and unregulated (VOCs, aldehydes, PAHs) air pollutants were investigated for diesel heavy duty buses equipped with different after-treatment systems (DPF+EGR and SCR) under urban driving cycle. The combustion temperature and the working temperature of SCR catalysts were important to make impact on NOx emissions, whereas PM emissions were low. The alkane groups dominated NMVOCs emissions, making 42.6~59.4% of sum of the NMVOCs emissions. Especially, alkane emissions of DPF+EGR-equipped vehicle included DOC had 14.9~15.5% higher than those of SCR-equipped vehicle due to low efficiency of oxidation catalyst. In the case of individual NMVOCs, n-nonane and propylene emissions highly occupied for DPF+EGR and SCR, respectively. Formaldehyde emissions among aldehydes were the highest and PAHs emissions were hardly detected except naphthalene and phenanthrene. The NMHC speciation has been shown to be the highest of the formaldehyde ranged 20.8~21.5%. The results of this study will be contributed to establish Korean HAPs emission inventory for automobile source.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.648-653
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• 2006

As an alternative for the traditional materials packed in biofilters treating gaseous VOCs, a novel packing material has been developed and tested. In the packing material(named as Hydrogel Bead, HB), pollutant-degrading microorganisms were immobilized in hydrogel consisted of alginate, polyvinyl alcohol(PVA), and powdered activated carbon. A closed-bottle study showed that the HB rapidly removed gaseous styrene without the losses of adsorption and biodegradation capacity. Biofilter column experiments using the HBs also demonstrated that greater than 95% of removal efficiencies were found at an inlet styrene loading rate of $245g/m^3/hr$, which was higher biofilter performance than other elimination capacity reported earlier. Furthermore, when the inlet styrene concentration increased stepwise, the adsorption played an important role in overall styrene removals. The absorbed styrene was found to be biodegraded in the following low inlet loading condition. Consequently, the new HB material is able to successfully minimize the drawbacks of activated carbon(necessity of regeneration) and biological processes(low removal capacity at dynamic loading conditions), and maximize the overall performance of biofilter systems treating VOCs.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.18-27
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• 2006

Air Sparging (IAS, AS) is a ground-water remediation technique, in which organic contaminants are volatilized into air as they rise from saturated to vadose soil zone. This study was conducted to investigate the variation characteristics of TPH, VOCs and $CO_2$ for air sparging of diesel contaminated saturated soil. Initial TPH concentration was 10,000 mg/kg for saturated soil phase and 1,001 mg/L for soil aquifer phase. After 36 days of air sparging, the equilibrium temperature of 2-Dimension experiment system was $24.9{\pm}1.5^{\circ}C$. The saturated soil TPH concentration (in the C10 port close to air diffuser) was reduced to 66.0% of the initial value. The mass amount of $CO_2$ was 3,800 mg and 3,200 mg in air space (C70 port) and in unsaturated soil zone (C50 port), respectively. The VOCs production kinetic parameter was 0.164/day in the air space (C70 port) and 0.182/day in the unsaturated soils (C50 port).

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.747-757
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• 2014

Since the air contamination by air pollutants from indoor construction materials and daily supplies has been increased in recent decades, the public interest of using environmentally friendly products and improving indoor air quality also attracted much attention. As known as effects of phytoncide, it has been used in construction materials and daily supplies with various method. In this study, hinoki cypress (Chamaecyparis obtusa) was used because of its high contents of phytoncide. The leaves of hinoki cypress (C. obtusa), which generated by pruning, were extracted by steam distillation, and then used as humidification water source. Volatile organic compound (VOC) from C. obtusa were characterized by GC-MS (Gas chromatograph-Mass spectrophotometry) in order to evaluate effects and risks of using C. obtusa extracts. Total 86 types and 116 types of VOC were detected from distilled water (DI water) and C. obtusa extracts, respectively. Aromatic compounds (DI water: 13 types, 53%; C. obtusa extracts: 13 types, 38%) and terpenoids (DI water: 16 types, 23%; C. obtusa extracts: 23 types, 33%) were detected more diverse types and higher amount than other compound categories. No additional aromatic compounds were found from C. obtusa extracts, so C. obtusa extracts did not affect on aromatic compounds emission. However, in terpenoids, total amount of emission from C. obtusa extracts increased to 33% from 23% (DI water) and 7 more types of compounds were found from C. obtusa extracts. Especially, from C. obtusa extracts, terpinen-4-ol was emitted 71 times higher than DI water. During the humidification with C. obtusa extracts, emitted terpenoid compounds were well known for higher anti-bacterial, anti-insect, and anti-septic functions, but also these had anti-hypertensive and anti-cancer activities. Therefore, terpenoids from C. obtusa extracts can help to improve public health by using humidifier.

• Analytical Science and Technology
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• v.20 no.6
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• pp.453-459
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• 2007

This study is for investigation of indoor conditions with air contamination after occupation 120 households in brand-new apartments by measuring the concentration of VOCs and carbonyl compounds. It has been found that TVOC (total volatile organic compounds; TVOCs) were $688.61{\mu}g/m^3$ after moving in. And formaldehyde, toluene, m, p-xylene, acetone and ethylbenzene were $158.56{\mu}g/m^3$, $146.58{\mu}g/m^3$, $69.28{\mu}g/m^3$, $63.80{\mu}g/m^3$ and $29.65{\mu}g/m^3$, respectively. The mean concentrations of indoor air pollutants tend to decrease along an increase dwelling period. But, the mean concentration of d-limonene increased from 2 months to 10 months. Also, toluene, ethylbenzene, m, p, o-xylene amounted to 38.8 % among VOCs studied, this ratio tend to decrease along with and increased dwelling period.

• Land and Housing Review
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• v.4 no.4
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• pp.417-424
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• 2013

The purpose of this study was to investigate the characteristics of the indoor air quality by season. The surveyed houses were 48 new apartment complex in 2012 across the country. The houses were carried out the bakeout before the test. The measuring method was "Indoor air quality testing standards process" and the measured items were formaldehyde, benzene, toluene, ethylbenzene, xylene, styrene average emissions. All the items were more emitting during the summer. From June to September the average concentration of formaldehyde emission was higher than other seasons. The average emissions of benzene concentrations in all seasons were released in small quantities. Average emissions of toluene and ethylbenzene concentration from April to August showed slightly higher emissions. Xylene and styrene concentration showed the highest emissions at April, but without large deviations throughout the year.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.331-341
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• 2018

Hazardous air pollutants(HAPs) in the atmosphere are regulated as major air pollutants in Korea by the Air Pollution Control Act. In order to manage and control HAPs, accurate standards, which are traceable to the International System of Units(SI), are required. In this study, primary standard gas mixtures(PSMs) of volatile organic compounds(VOCs) which are specified as HAPs were developed at $1{\mu}mol/mol$ levels. The selected fourteen VOCs include Benzene, Toluene, Ethylbenzene, m-Xylene, Styrene, o-Xylene, Chloroform, 1,1,2-Trichloroethane, Trichloroethylene, Tetrachloroethylene, 1,1-Dichloroethane, Carbon tetrachloride, 1,3-Butadiene, and Dichloromethane. The HAPs PSMs were gravimetrically prepared in aluminum cylinders and their consistency was verified within the relative expanded uncertainty of 0.71% (k=2). Potential adsorption loss onto the internal surface of cylinders was estimated by cylinder-to-cylinder division method. No adsorption loss was observed within the uncerainty of 0.53%. The long-term stability of the HAPs PSMs was evaluated comparing with freshly prepared HAPs PSMs. The HAPs PSMs were stable for one year within the uncertainty of 0.38%. The final uncertainty of the PSMs was determined by combining the preparation uncertainty, verification uncertainty, and stability uncertainty. Finally, traceable and stable HAPs PSMs at $1{\mu}mol/mol$ levels were developed with the uncertainty of less than 0.76% in high-pressure aluminum cylinders.

• KIEAE Journal
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• v.17 no.3
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• pp.125-131
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• 2017

Purpose: The study is to measure concentrations of indoor air pollutants in housing and to analyze the characteristics of pollutants in housing indoor-air between summer and winter comparatively. The research result could be used as data for public health through indoor air quality management of existing housing and more as a reference for new housing. Method: It was investigated 24 middle class housings of metropolitan area in winter which have been built for the past 30 years. Concentration of HCHO, TVOC was investigated in living room at morning and night and concentration of $CO_2$ was investigated in living room and master bedroom at morning and night. SKT100-X5 was used for concentration of HCHO, TVOC and ZGm053UK for concentration of $CO_2$. The characteristics of HCHO, TVOC, $CO_2$ concentration in winter were analyzed and then the concentrations in winter were analyzed the concentrations in summer being preceding research comparatively. Result: Average concentration of TVOC in winter was 2.7 times more than that of TVOC in summer, average concentration of HCHO in winter was about 2.0 times more than that of HCHO in summer. Average concentration of $CO_2$ in the morning at living room in winter was 1.3 times more than that of $CO_2$ in summer. Average concentration of $CO_2$ in the morning at master bedroom in winter was 1.1 times more than that of $CO_2$ in summer. Average concentration of TVOC was 1.31 times more than that of HCHO and standard deviation of that was 1.73 times higher. Average concentration of $CO_2$ was almost nearly close or over to 1,000ppm being criteria of the Ministry of Environment.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.742-747
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• 2008

Formaldehyde(HCHO) and total volatile organic compounds(VOCs) can cause adverse health effects to the building occupants and may contribute to symptoms of 'Sick Building Syndrome'. These chemical contaminants are emitted from furnishings and electronic equipments as well as building materials. The purpose of this study is to measure and analyze VOCs and HCHO emission concentration from furnitures composed of wood materials including various chemicals by the large chamber method. This paper presents experiment results on the emission concentration of TVOCs and HCHO released from furnitures, such as bed, kitchen, sofa and table by a large chamber($24m^3$). The temperature and air humidity in the chamber are controlled to $25{\pm}1{\circ}C$ and $50{\pm}5%$ for this experiment. When the air change rate is $0.5hr^{-1}$, the background concentrations within the large chamber are below $50{\mu}g/m^3$ for TVOC, $5{\mu}g/m^3$ for HCHO and individual VOCs. The study is investigated the characterization of the chemical emission TVOC and HCHO concentrations and unknown VOCs from 6 furnitures.