• Journal of Environmental Health Sciences
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• v.43 no.2
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• pp.122-129
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• 2017

Objectives: Most of the $PM_{10}$ in subway stations is spread by the train-induced wind from the tunnels. Therefore, in order to improve air quality in subway stations, it is important to remove the $PM_{10}$ from the tunnels. After the installation of PSD (platform screen doors), the influence of train-induced wind and $PM_{10}$ at the platform has decreased, but is estimated to have increased in subway tunnels. This study was conducted to investigate the control of $PM_{10}$ in subway tunnels by applying a 500-fold diluted solution mixed with a humectant using a natural polymer. Methods: For this purpose, we tested the dust reduction effect in a laboratory and corrosion test and water pollution using fish and aquatic plants for the natural dust collecting agent. In the tunnel of a subway station, we used the natural dust collecting agent over 15 days. The study was carried out on $PM_{10}$ control during operation, which accounts for more than 70% of subway dust. Results: As results, the natural dust collecting agent exhibited an excellent dust control effect, and it was safe for water quality and soil. It showed the effect of controlling $PM_{10}$ in the subway tunnel by 49.5- 64.7% over 15 days. The use of the dust collecting agent for the control of $PM_{10}$ could be confirmed in the subway. Conclusion: It is necessary to clearly explain the major portions of chemical components contained in $PM_{10}$ to figure out the characteristics of $PM_{10}$ and to develop effective reduction measures to decrease the adverse effects of $PM_{10}$ in the subway.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.439-441
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• 2007

The seoul metropolitan subway has installed 8 lines and about 500 stations to transport 5 million passengers everyday. The underground air pollution level in the subway stations is very severe status, which is very harmful to the commutators and its personals. Although subway roles as such a massive and huge transportation system, the subway doesn't adapt yet any real-time air monitoring system. They have only some hand-held type detector equipments for monitoring air pollution. Therefore subway passengers are exposed to the harmful air pollution environment. The most harmful environmental parameters among the air pollution are known as the dust and sound noise dB level in the subway station. Because the dust is consisted of very small particles, we can't see them easily in dark condition on the platform, but it is very harmful. The monitoring system for air pollution is developed using embedded system attached with 6 different environmental sensors. This system monitors air pollution of dust sound noise, gas, temperature, humidity, inflammable gas, toxic gas in the subway ?station. The sensor unit of the ARM-CPU board and sensor transmits real time environmental data to the main server using Zigbee wireless communication module and TCP/IP network. The main control server receives and displays the real-time environmental data, and it send alarms to the personals when high level value.

• Particle and aerosol research
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• v.11 no.2
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• pp.37-46
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• 2015

Dust particles, which inflow to the subway mechanical ventilation and air conditioning(MVAC) chamber, contain a fair amount of iron compounds, approximately 25.2w/w%. This work attempted to capture those iron containing dust using magnetic filters. Average magnetization value of the test MVAC dust was 0.012 emu on 5,000 Oe, which could correspond sufficiently with the magnetic interaction. External permanent magnets provided with magnetization of iron mesh screen showing high gradient magnetic field(HGM). It resulted in the capture efficiency with 84.0 ~ 99.7% and 81.2 ~ 99.8% for $PM_{10}$ and $PM_{2.5}$ respectively. Magnetic capture was found to be closely associated with the magnetic intensity, mesh opening size and flow velocity.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.13-18
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• 2023

A subway station is a prominent multi-purpose facility where the quantitative management of fine dust, generated by various factors, is conducted. Recently, eco-friendly air purification methods using air-purifying plants are being discussed, with the focus on biofiltration through vegetation. Previous research in this field has confirmed the reduction effects of transition metals such as Fe, which have been identified as harmful to human health. This study aimed to identify the sources of fine dust dispersion within subway stations and derive an efficient operational strategy for air-purifying plants that takes into account the behavior characteristics of fine dust within multi-purpose facilities. The experiment monitored regional fine dust levels through IAQ stations established based on prior research. Also, the data was analyzed through time-series and correlation analyses by linking it with passenger counts at subway stations and the frequency of train stops. Furthermore, to consider energy efficiency, we conducted component-specific power consumption monitoring. Through this study, we were able to derive the optimal operational strategy for air-purifying plants based on time-series comprehensive analysis data and confirm significant energy efficiency.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2117-2121
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• 2010

Many passengers complain about the air quality of subway stations, mostly due to the dust. Usually, this dust is usually originated from tunnels, passengers, or outdoor air. As for now, the dust from tunnels and passengers is not easy to control, but relatively easy to control that from outdoor air. In this study, the effect of outdoor air on the subway air quality was investigated, and various factors was found to be effective. Based on these results, some strategies for the improvement of air quality in subway stations were suggested in this study.

• Journal of Environmental Health Sciences
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• v.30 no.2
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• pp.154-160
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• 2004

The purpose of this study was to evaluate airborne concentrations and characteristics of TSP, IPM, TPM and RPM in Seoul subway stations. Sampling was performed at 14 stations from April 11 to 29, 2002. Size-selective dust concentrations and metal concentrations were measured by gravimetric method and ICP-AES, respectively. The geometric mean of TSP, IPM, TPM and RPM concentrations in Seoul subway stations were 176$\mu\textrm{g}$/㎥, 348$\mu\textrm{g}$/㎥, 158$\mu\textrm{g}$/㎥ and 104$\mu\textrm{g}$/㎥, respectively. Dust concentrations in pathway were the highest and those in lobby were the lowest. The size distribution of dusts was significantly different by location of collection. When the deposition rate into pulmonary gas exchange region was estimated by size distribution, the deposition rate of dust collected from platform was higher than those of dust collected from lobby and pathway. The lower the basement levels were, the higher the deposition rates of dusts into tracheobronchial region and gas exchange region were. Copper and iron concentrations measured in platform higher were than those in other areas.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1388-1398
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• 2011

Air pollution in subway tunnel is primarily caused from the wear of metallic materials. As undesirable substance, PM(Particulate Matter) can especially harm the health of passengers and workers as well as clog the main parts of rolling stock such as inverters. To improve the air quality in subway tunnel, SMRT(Seoul Metropolitan Rapid Transit Corporation) has developed anti-pollution devices such as Magnetic Dust Collector, Vacuum Cleaner For Rail Road and Particulate Removing Sprinkler Vehicle. Introducing these mechanical devices, this paper is mainly devoted to explaining the characteristics of collected dust according to the result of particle-size analysis and componential analysis.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.5
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• pp.625-633
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• 2013

This study attempted to find an alternative method for fine dust control in the pre-exiting facilities of metro-subway stations. A new double-layer design was proposed for the MVAC (mechanical ventilation and air control) system. Several filter lay-outs were combined a pre-filter with electret filter (EF), electret bundle filter (EBF), or electret pleated filter (EPF), and were then examined focusing on the collection efficiency of particulate matters and pressure drop across the filter layers. The experimental results from the lab and field tests showed the best collection efficiency with EPF, which achieved 85% for $PM_{10}$ and 55% for $PM_{2.5}$. It was also found from the long term field test that the new filter lay-out could provide quite consistent dust level particularly in underground platform regardless of external condition.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.287-295
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• 2010

Dust samples have been collected from streets, schools, subway stations and households in Daegu metropolitan city. Samples were sieved through a 100 ${\mu}m$ mesh and the concentration of 14 elements have been determined using by ICP after acid extraction. Results showed that Ca, Fe, K, Mg, Mn, Na and V were influenced by natural sources while Cd, Cr, Cu, Ni, Pb and Zn were influenced by anthropogenic sources. The measured values were remarkably higher in components from natural sources than in components from anthropogenic sources. In particular, school dust had higher levels of Ca and Pb and subway station dust had higher levels of Cu and Zn. The percentage composition of chemicals from subway stations, households, and schools were remarkably higher in components from anthropogenic sources than that from streets. It is well recognized that anthropogenic sources were affected by indoor dust. Results of pollution index of hazardous heavy metals indicated that schools, households, and subway stations were more contaminated than streets and urban areas typically had higher pollution index than rural areas. The correlation analysis among trace elements seem to suggest that there were correlations between components of soil/road dust resuspension, and components of waste incineration and fuel combustion.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.523-528
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• 2011

Subway becomes more and more main transportation in major cities. Air pollution in the subway platforms is decreased; however, dust flow inside subway tunnel and train is increased by installing Platform Screen Door. Airflow inside subway tunnel is observed using computational method in this study The airflow characteristics around ventilation shafts and inside the tunnel is studied following the train movement, while the train moves from existing Miasamgeori station to Gireum station ANSYS CFX V12.0.l and ICEM CFD V12.0.l are used to compute the airflow inside the subway tunnel.