• Journal of Environmental Impact Assessment
• /
• v.5 no.1
• /
• pp.79-85
• /
• 1996

Simultaneous monitoring in many locations is necessary to evaluate the air quality and analyze future trend of a city, For this purpose, it is essential to install air pollution monitoring network. The first automatic air pollution monitoring network was introduced Seoul in 1973. As of 1995, 20 monitoring stations are now in operation. Concerning the management of the air pollution monitoring network, there was some argument among the relavant scholars, non-governmental organization(NGO) and the government organization. So far, there was no extensive evaluation and analysis about the network. The purpose of this study was to evaluate the representativeness of air quality monitoring network through actual measurement of the concentration of the air pollutant. The concentration of NOx was extensively measured widely in Seoul area three times using the TEA simple measuring technique. Even the judgement level for the area representativeness was lowered to 80%, Ssangmun-dong monitoring station tend to overestimate the pollutant concentration of the covered area. While, Sinlimdong monitoring station tend to underestimate the pollutant concentration of the covered area.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.19 no.2
• /
• pp.142-148
• /
• 2007

The purpose of this study is to suggest the effective ventilation strategies and control methods that can minimize energy cost maintaining acceptable IAQ level in apartment house. The effects of the air-cleaning and heat-recovery ventilation system on IAQ under various operating conditions are investigated based on the experimental and CFD analyzed results. The results can be summarized as follows. (1) When a ventilator is not operated, the concentration of several pollutants may highly show in the house even though environment-friendly building materials are applied. Therefore, a mechanical ventilation system is required to obtain proper ventilation. (2) The pollutant concentration is noticeably deceased under air-cleaning/ventilation mode of air-clinic system, however, pollutant of kitchen is stagnant, because fresh air is not carried into the kitchen. (3) When air-clinic system is only equipped at master bedroom and living room, the system does not effectively deliver fresh air throughout the whole house, and then high pollutant concentration is obtained in each room. In contrast the average pollutant concentration meets the guideline when air-clinic system is installed at each room. (4) The air-cleaning/ventilation mode significantly affects on room ventilation in comparison with ventilation mode only.

• Atmosphere
• /
• v.25 no.4
• /
• pp.659-667
• /
• 2015

In this study, sensitivity of inflow wind speed and turbulent Schmidt number to pollutant dispersion in an urban street canyon is investigated, by comparing CFD-simulated results to wind-tunnel results. For this, we changed systematically inflow wind speed at the street-canyon height ($1.5{\sim}10.0m\;s^{-1}$ with the increment of $0.5m\;s^{-1}$) and turbulent Schmidt number (0.2~1.3 with interval of 0.1). Also, we performed numerical experiments under the conditions that turbulent Schmidt numbers selected with the magnitude of mean kinetic energy at each grid point were assigned in the street canyon. With the increase of the inflow wind speed, the model underestimated (overestimated) pollutant concentration in the upwind (downwind) side of the street canyon because of the increase of pollutant advection. This implies that, for more realistic reproduction of pollutant dispersion in urban street canyons, large (small) turbulent Schmidt number should be assigned for week (strong) inflow condition. In the cases of selectively assigned turbulent Schmidt number, mean bias remarkably decreased (maximum 60%) compared to the cases of constant turbulent Schmidt number assigned. At week (strong) inflow wind speed, root mean square error decreases as the area where turbulent Schmidt number is selectively assigned becomes large (small).

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2002.10a
• /
• pp.449-452
• /
• 2002

Characteristics of pollutant load during irrigation and non-irrigation periods was investigated for streamwater from a rural watershed. Water was sampled and discharge was measured at 5-days intervals at outlet of study area. The mean concentrations of TN and TP in an irrigation period are higher than in an non-irrigation period, while mean COD concentration in an irrigation period is lower than in a non-irrigation period. For increasing discharge during an irrigation period, TN concentration increase, TP concentration is nearly unchanged, and COD concentrations decreases.

• Journal of Korean Society for Atmospheric Environment
• /
• v.11 no.E
• /
• pp.45-54
• /
• 1995

Indoor air quality models are useful to predict indoor air pollutant concentrations as a function of several indoor factors. Indoor air quality model was developed to evaluate the pollutant removal efficiency of variable-air-volume/bypass filtration system (VAV/BPFS) compared with the conventional variable-air-volume (VAV) system. This model provides relative pollutant removal effectiveness of VAV/BPFS by concentration ratio between the conventional VAV system and VAV/BPFS. The predictions agree closely, from 5 to 10 percent, with the measured values for each energy load. As a results, we recommend the VAV/BPFS is a promising alternative to conventional VAV system because it is capable of reducing indoor air pollutant concentration and maintaining good indoor air quality.

• Journal of computational fluids engineering
• /
• v.4 no.3
• /
• pp.12-20
• /
• 1999

The computations of the flowfield and pollutant dispersion over a flat plate and the Russian hills of various slopes are described. The Gaussian plume and the puff model have been used to calculate concentration of pollutant. The Reynolds-averaged unsteady incompressible Navier-Stokes equation with low Reynolds κ-ε model has been used to calculate the flowfield. The flow data of a flat plate and the Russian hills from Navier-Stokes equation solutions has been used as the input data for the puff model. The computational results of flowfield agree well with experimental results of both a flat plate and Russian hills. The concentration prediction by the Gaussian plume model and the Gaussian puff model also agrees flirty well with experiments.

• Journal of Environmental Impact Assessment
• /
• v.16 no.2
• /
• pp.169-176
• /
• 2007

The paved areas in nonpoint source are highly polluted landuses because of high imperviousness and pollutant mass emissions, such as sand, cereals, and dust from vehicle activities. Most of them in highways are collected by cleaning trucks or discharged to the adjacent soil and water system through the drain ditch in stormwater. Therefore, it is necessary to investigate the relationship between water concentration and total pollutant loadings from the paved areas. From the experiment, CODcr concentration of the cleaning wastewater was 17 times greater than that of the stormwater runoff. Also, concentrations of heavy metals (Cu, Fe, Zn) were 1.3 to 1.5 times higher when compared to the stormwater runoff. While total discharged loadings was insignificant in the cleaning wastewater. In conclusion, these results provide some evidence that the stormwater runoff may be managed carefully to the aspect of total pollutant loadings and the cleaning wastewater may be handled cautiously with the pollutant concentrations in highways.

• International Journal of Highway Engineering
• /
• v.16 no.6
• /
• pp.9-17
• /
• 2014

PURPOSES : The purpose of this study is to assess removal efficiency of non-point pollutants and applicability for non-point pollutant reduction facilities by conducting the demonstration project operation. METHODS : In order to analyze removal efficiency of non-point pollutants for facilities such as a grassed swale, a small constructed wetland, a free water surface wetland, a horizontal sub-surface flow wetland, and a sand filtration, the field data including specifications of facilities, rainfall, inflow and runoff rainfall effluent etc. was acquired after occurring rainfall events, and the acquired data was analyzed for removal efficiency rate to assess road non-point pollutants facilities using event mean concentration (EMC) and summation of load (SOL) methods. RESULTS : The results of analyzing rainfall effluent, non-point pollutant sources showed that total suspended solid (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total nitrogen (TN), total phosphorus (TP), chrome (Cr), zinc (Zn), and lead (Pb) can be removed through non-point pollutant reduction facilities by 60.3% ~ 100%. Especially removal efficiency of TSS, COD and BOD is relatively higher than removal efficiency of other non-point pollutant sources in all kind of non-point pollutant facilities. CONCLUSIONS : Based on the result of this study, even though natural type of non-point pollutant reduction facilities for roads occupy small areas comparing with drainage basin areas, most of non-point pollutant sources would be removed through the facilities.

• Korean Journal of Ecology and Environment
• /
• v.38 no.spc
• /
• pp.67-75
• /
• 2005

The objectives of this study were to understand the runoff characteristics of the non-point sources originating from impervious surfaces and to assess their effect on the aquatic environment in the urban areas. The concentration of pollutants (SS, BOD, COD and T-P) except for T-N showed the highest value in runoff from road, and event mean concentration (EMC) also showed high value from road. The pollutants discharged from road showed a higher concentration in the beginning stage (0 ${\sim}$ 30%) of progressive percentage of rainfall. The contribution percentages of non-point sources by load were 44.9% for SS, 11.2% for BOD, 21.4% for COD, 11.4% for T-N and 8.1% for T-P in the total load of pollutant discharged through sewer. From our results, the road was a significant potential source that deteriorated water quality of the streams and lakes in the vicinity of the urban area during the rain period. Therefore, counter plan is required to reduce pollutant concentration on the road from non-point sources in the urban area. Also, since pollutant concentration in the beginning stage of rainfall was quite high, road cleaning seems to be one of the very useful methods to prevent inflowing of pollutants to the aquatic environment.

• Journal of computational fluids engineering
• /
• v.6 no.4
• /
• pp.1-7
• /
• 2001

Wind flow perturbations, recirculations and turbulence generated by buildings often dominate air pollutant distributions around buildings. This paper describes dispersion of contaminants in the vicinity of a building by solving the concentration equation based on previously simulated wind flow field. Turbulence closure is achieved by using the standard k-ε two-equation model. The paper shows application of the CIP method for solving a species concentration equation of contaminant gas around a rectangular building for two different sources under conditions of neutral atmospheric stratification. Results have been compared to the experimental data and the previous numerical results by hybrid scheme. The computational results of concentration profiles by the CIP method agree well with experimental data.