• Journal of the Korean Solar Energy Society
• /
• v.35 no.1
• /
• pp.97-106
• /
• 2015

Gypsum board is easy to manufacture of a variety of forms and has stable mechanical properties and thermal properties. And gypsum boards are widely used to the walls and ceiling of the building as the interior building materials. The studies about technology of applying the various features in the gypsum board with additives are being actively investigated. Development methods for enhancing performance of the gypsum board using additives are largely divided into two categories. The first case is functional gypsum board that is to improve the moisture absorption and moisture-proof properties. Also studies of adsorption and decomposition of indoor air pollutants of the gypsum board using porous materials as an additive are being actively investigated. Another case is applying thermal storage materials which gives the heat storage performance to gypsum board. In this paper, we would like to introduce the various cases of gypsum board applied various additives.

• Journal of Environmental Health Sciences
• /
• v.47 no.4
• /
• pp.339-355
• /
• 2021

Background: Particulate matter (PM₁₀, PM_2.5) and black carbon contribute to poor air quality in urban areas, and can also affect indoor environments. Exposure to PM can be associated with respiratory and lung diseases. Objectives: This study investigated the indoor and outdoor concentration distribution patterns of PM₁₀, PM_2.5, and black carbon at an apartment building, a typical residential space in the metropolitan areas of South Korea, by season, day of the week (weekday vs. weekend), and time of the day. It aims to obtain foundational data for the effective management of pollutants and investigate the difference in pollution levels between indoor and outdoor environments. Methods: Indoor and outdoor concentrations of PM and black carbon were measured at an apartment building located in Namyangju, Gyeonggi-do Province, using dust sensors and an Aethalometer AE51 (AethLabs, San Francisco, CA, USA) over the course of a year from June 2020 to May 2021. The concentration distribution patterns were analyzed by season and time of day. Results: PM₁₀ and PM_2.5 concentrations in the outdoor environment were higher than those in the indoor environment, regardless of the season. By contrast, the indoor black carbon concentration was higher than that in the outdoor environment during summer and autumn. The concentrations of PM₁₀, PM_2.5 and black carbon were found to be higher on weekdays than during weekends, especially during rush hour, with concentrations of 25.92~56.58 ㎍/m³, 21.12~44.82 ㎍/m³, 0.63~3.40 ㎍/m³. Conclusions: The outdoor concentrations of PM₁₀, PM_2.5, and black carbon were higher during the weekdays, especially during rush hour, than during weekends. This study is expected to provide basic data for the health management of apartment occupants because it is measured over a period of more than one year.

• Horticultural Science & Technology
• /
• v.33 no.4
• /
• pp.605-617
• /
• 2015

The ultimate goal of this research is to develop a botanical biofiltration system that combines a green interior, biofiltering, and automatic irrigation to purify indoor air pollutants according to indoor space and the size of biofilter. This study was performed to compare the stability of air flow characteristics and removal efficiency (RE) of fine dust within a wall-typed (vertical) botanical biofilter depending on humidifying cycle and to investigate RE of volatile organic compounds (VOCs) by the biofilter. The biofilter used in this experiment was designed as an integral form of water metering pump, water tank, blower, humidifier, and multi-level planting space in order to be suitable for indoor space utilization. As a result, relative humidity, air temperature, and soil moisture content (SMC) within the biofilter showed stable values regardless of three different humidifying cycles operated by the metering pump. In particular, SMCs were consistently maintained in the range of 27.1-29.7% during all humidifying cycles; moreover, a humidifying cycle of operating for 15 min and pausing for 45 min showed the best horizontal linear regression (y = 0.0008x + 29.09) on SMC ($29.0{\pm}0.2%$) during 120 hour. REs for number of fine dust (PM10) and ultra-fine dust (PM2.5) particles passed through the biofilter were in the range of 82.7-89.7% and 65.4-73.0%, respectively. RE for weight of PM10 passed through the biofilter was in the range of 58.1-78.9%, depending on humidifying cycle. REs of xylene, ethyl benzene, total VOCs (TVOCs), and toluene passed through the biofilter were in the range of 71.3-75.5%, while REs of benzene and formaldehyde (HCHO) passed through the biofilter were 39.7% and 44.9%, respectively. Hence, it was confirmed that the wall-typed botanical biofilter suitable for indoor plants was very effective for indoor air purification.

• Journal of the Korean Society of Safety
• /
• v.9 no.1
• /
• pp.134-139
• /
• 1994

In order to assess the level of atmospheric pollution and to contribute the hearth improvement of residents in Taejon city, the authors were measured the concentration of air pollutants(CO, SO$_2$, NO$_2$, TSP, Pb, Cd, Cr) at three places of the control road in Taejon. The investigative research performed bimonthly from May 1993 to September 1993, and the places were the underground shopping stores of Taejon station, Dongyang department store and provincial goverment areas. The results of statistical analysis are as followings. \circled1CO :0.569~0.966ppm \circled2SO$_2$：0.084~0.170ppm \circled3NO$_2$:0.0045~0.022ppm \circled4TSP：249~299$\mu\textrm{g}$/㎥. \circled5Pb :0.366~1.157$\mu\textrm{g}$/㎥. \circled6Cd：0.016~0.025$\mu\textrm{g}$/㎥. \circled7 Cr : 0.198 ~0.290$\mu\textrm{g}$/㎥. The mean concentration of SO$_2$in Dongyang department store area was 0.17ppm, and it exceeded the ambient air quality standard by 0.02ppm. The concentration of TSP was higher than a standing rule of public hygiene, and it was very near to a standing rule of environmental preservation. The standing rule of indoor air pollution in underground shopping store have two different laws, the public hygiene and the environmental preservation. Therefore, it was difficult to judge what to do in such circumstance. In regarding to the laws, an environmental standard for air pollution in the underground space must unify into the standard of public hygiene.

• Particle and aerosol research
• /
• v.5 no.2
• /
• pp.37-43
• /
• 2009

Particulate matter (PM) is one of the major indoor air pollutants especially in the subway station in Korea. In order to remove PM in the subway station, several kinds of PM removal system such as roll-filter, auto-washable air filter, demister, and electrostatic precipitator are used in the air handling unit (AHU) of subway stations. However, those systems are prone to operation and maintenance problems since the filter-regeneration unit consisting of electrical or water jet parts might malfunction due to the high load of particulates unless the filter medium is periodically replaced. In this study, the use of axial-flow cyclone was proposed for particulate filter unit in the AHU for its low operation and maintenance cost. Novel shape of axial-flow cyclone was designed by using computational fluid dynamics (CFD). The shape of vortex vane was optimized in terms of pressure drop and tangential velocity. In addition, CFD analysis was validated experimentally through the pressure drop measurement of mock-up model. We found that pressure drop and tangential velocity of fluid through the axia-flow cyclone was significantly affected by the rotating degree of vortex vane and the numerical prediction of pressure drop agreed well with experimental measurement.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.8
• /
• pp.528-533
• /
• 2014

Recently, people interest in environmental pollution and attempt to improve the indoor air quality contaminated with various pollutants since it is very important to construct healthy and comfortable living environment. In the current study, we used the technology that has first received the certification of green technology for improving the removal efficiency of malodor causing substances. This green technology is a new technology to increase the reactivity of the odorous substances with OH radicals for oxidation reaction by using an infrared lamp in the existing air purification system. Comparing the efficiency of the green technology with the infrared lamp to that of the existing technology of air cleaner, there was a difference in the decomposition efficiency depending on the initial concentrations and speciation of the odorous substances. The removal efficiencies of contaminants were enhanced by 16.9 and 13.2% at low and high concentrations, respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.26 no.12
• /
• pp.588-593
• /
• 2014

To maintain a negative pressure, the supply, exhaust airvolume are adjusted by setting volume damper and the infiltration through leakage area of the door between rooms in biosafety laboratory. Multizone simulation is useful way to predict room pressure, supply and exhaust air volume. But in a particular room, local change such as airflow and contaminants concentration distribution can not be evaluated unfortunately. Through this study, a coupled multizone and CFD simulation was performed, indoor air flow and local contaminants concentration distribution in a particular room of BSL lab are predicted. The results show that all zones of BSL lab are well ventilated by unidirectional flow without local stagnation. In addition, in case that unexpected biohazard is occured in BSL lab, multizone simulation results about the spread of pollutants along movement of the occupant also show that contaminants concentration is removing totally without the spread of the outside. In conclusion, a coupled multizone and CFD simulation can be applied to interpret differential pressure in room and local change of physical quantity in a particular room such as airflow and Influenza A contaminants concentration distribution. This simulation method is useful to enhance the reliability and accuracy of biosafety laboratory design.

• Carbon letters
• /
• v.19
• /
• pp.79-88
• /
• 2016

As a replacement for activated carbon, biochar was synthesized and used for the adsorptive removal of formaldehyde and nitrogen oxide. Biochar was produced from the fast pyrolysis of the red marine macro alga, Pyropia tenera. The P. tenera char was then activated with steam, ammonia and KOH to alter its characteristics. The adsorption of formaldehyde, which is one of the main indoor air pollutants, onto the seaweed char was performed using 1-ppm formaldehyde and the char was activated using a range of methods. The char activated with both the KOH and ammonia treatments showed the highest adsorptive removal efficiency, followed by KOH-treated char, ammonia-treated char, steam-treated char, and non-activated char. The removal of 1000-ppm NO over untreated char, KOH-treated char, and activated carbon was also tested. While the untreated char exhibited little activity, the KOH-treated char removed 80% of the NO at 50℃, which was an even higher NO removal efficiency than that achieved by activated carbon.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2005.06a
• /
• pp.319-322
• /
• 2005

Porous building materials are not only sources of indoor air pollutants such as volatile organic compounds (VOCs) but they are also strong sinks of these pollutants. Volatile organic compounds have been implicated in impaired spermatogenesis, increase in the incidence of malformed sperm and decrease in the percentage of moving sperm. The aim of this study was to determine and compare the direct effects of various volatile organic compounds (phenol, formaldehyde; HCHO, ethanol, toluene, styrene) on motility and survival rate of human sperm in vitro. Semen samples from 3 health subjects were prepared using swim-up method and 1-10mM volatile organic compounds were added to the test medium. HCHO and phenol produced significant decreases in the motility and survival rate with a different potency. The most potent inhibition of motility and survival rate was observed after exposure to HCHO. Less than 1mM HCHO significantly inhibited sperm motility. When ethanol is added directly to sperm, at concentrations equivalent to that in serum after heavy drinking, these damaging effects were lowest compared with other volatile organic compounds. Present study shows that each compound has differential toxic potency to human sperm and we need special caution for the use of HCHO and phenol.

• Korean Journal of Materials Research
• /
• v.16 no.11
• /
• pp.692-697
• /
• 2006

Deodorization of natural zeolites have been improved not only for polar but also for non-polar pollutants by sucessive ion exchanges of H and Ag ions starting from Korean natural zeolite with high adsorption capacity. The modified zeolites with $TiO_2$ coating on the surface revealed high deodorization and photocatalytic decomposition effects. Further modification was made with $10{\sim}20nm$ silica nano particles coating on the surface, the resulting composite particles of $SiO_2/TiO_2/modified$ natural zeolite revealed not only comparable deodorization but also better durability and resisatnce to color change compared to the $TiO_2$/modified natural zeolite without much compensation of photocatalytic decomposition effect, when the composite particles were exposed to the polypropylene non-woven fiber coated with organic binder. It is expected for the composite particle prepared here to be used as indoor building materials for indoor air quality control.