• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.617-622
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• 2000

Concentration of pollutants and discharge were monitored regularly at paddy field area during irrigation periods. The amounts of irrigation water during irrigation water during irrigation periods in 1999 were 3690mm. The concentration of pollutants in ponded water are high during fertilizer application period. The ratio of discharge of direct runoff Q$\_$D/ to the total runoff is 9%. The ratios of the load of direct runoff L$\_$D/ to the total load L$\_$T/ are 6% for T-N, 16% for T-P and 16% for COD. It was found that the ratios of the concentration are 0.7 for T-N, 1.8 for T-P and 1.9 for COD. The unit load of T-N, T-P and COD during irrigation periods were 12.1kg/㏊, 0.42kg/㏊ and 85.7kg/㏊, respectively

• 대기
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• 제18권1호
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• pp.25-32
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• 2008

Log normalized volume size distribution (dV/dlog$D_p$) with 52 size ranges from 0.5 to $20.0{\mu}m$ was measured for the cases of high $PM_{10}$ mass concentration (> $200{\mu}gm^{-3}$) using the Aerodynamic Particle Sizer (APS) at the Korea Global Atmosphere Watch Center (KGAWC) from 6 April, 2006 to 5 April, 2007. Black Carbon (BC), gaseous pollutants of $NO_X$ and $SO_2$ and ${\AA}ngstr\ddot{o}m$ exponent were also measured to examine the properties of the volume size distribution. From distinct difference of the high volume concentration (> $100{\mu}m^3cm^{-3}$), the volume size distribution for each event day was clasified into four types: (1) Type 1 had the high volume concentration for supermicron particles from 2.3 to $6.0{\mu}m$ and maximum average volume concentration was $160.7{\mu}m^3cm^{-3}$ at $3.5{\mu}m$. (2) Type 2 represented the high volume concentration in the both size range of submicron ($0.7-1.0{\mu}m$) and supermicron particles ($2.1-4.1{\mu}m^3cm^{-3}$ and $136.2{\mu}m^3cm^{-3}$ were found at 0.8 and $3.3{\mu}m$ respectively. (3) Type 3 showed the high volume concentration in the size range of $0.5-3.5{\mu}m$ and highest volume concentration of $201.1{\mu}m^3cm^{-3}$ at the particle size bin of $0.8{\mu}m$. (4) Type 4 was characterized by the high volume concentration for the fine particles less than $1.2{\mu}m$ and very high concentration of $446.8{\mu}m^3cm^{-3}$. ${\AA}ngstr\ddot{o}m$ exponent, concentration of gaseous ($NO_X$ and $SO_2$), and particle (BC) pollutants suggested that Type 1 was a typical volume size distribution for the Asian dust and Type 3 provided transportation of air pollutants. The distribution in Type 2 found to have both characteristics of the Asian dust and air pollutants, and Type 4 was took place during the foggy atmosphere containing high density of local pollutants. Based on the properties of volume size distribution, we can identify the three major events contributing the increase of $PM_{10}$ mass concentration, and hope to provide a guideline for discriminating the Asian dust from high $PM_{10}$ events. More case studies and longeto advance this determination method.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.639-642
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• 2003

Characteristics of concentration of pollutants such as total nitrogen(T-N), total phosphorus(T-P) and chemical oxygen demand(COD) during dry days of $2002{\sim}2003$ were 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 pollutants in non-irrigation and irrigation period not significantly different. For increasing discharge in 2002, TN concentration increased but COD concentrations decreases.

• 한국환경과학회지
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• 제3권1호
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• pp.31-38
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• 1994

The diffusion of the pollutants released into atmosphere is dependent on its chemical reaction, topography and micrometeorological characteristics. The purpose of the study is to investigate how much micrometeorological characteristics such as stability, wind speed and mixing height affect the diffusion of the air pollutants. For this purpose, this paper let 1) the basic theory be K-theory, 2) eddy diffusivity and wind speed be dependent on mixing height and stability, and 3) Grout method be used for numeric calculation. The result was 1) the more unstable condition, the higher mixing height and the higher wind speed we, the lower pollutants concentration appears, 2) the most intensive effect on the distribution of the pollutant concentration is the atmospheric stability.

• 대기
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• 제14권4호
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• pp.3-18
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• 2004

Neglecting the vertical transport from the surface, most of the previous studies on the long-range transport of pollutants have only considered the horizontal transport caused by the free atmosphere wind. I used a three dimensional numerical model, MM5 (The fifth generation Penn State Univ./NCAR Mesoscale Model) for the simulation of vertical transport of pollutants and investigated the mechanism of the vertical transport of atmospheric pollutants between planetary boundary layer(PBL) and free atmosphere by fronts. From the three dimensional simulation of MM5, the amount of pollutants transport from PBL to free atmosphere is 48% within 18 hour after the development of front, 55% within 24 hour, and 53% within 30 hour. The ratios of the vertically transported pollutant for different seasons are 62%, 60%, 54%, and 43% for spring, summer, fall, and winter, respectively. The most active areas for the vertical transport are the center of low pressure and the warm sector located east side of cold front, in which the strong upward motion slanted northward occurs. The horizontal advection of pollutants at the upper level is stronger than at the lower level simply because of the stronger wind speed. The simulation results shows the well known plum shape distribution of pollutants. The high concentration area is located in the center and north of the low pressure system, while the second highest concentration area is in the warm sector. It is shown that the most important mechanism for the vertical transport is vertical advection, while the vertical diffusion process plays an important role in the redistribution of pollutants in the PBL.

• 한국산업보건학회지
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• 제24권1호
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• pp.46-51
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• 2014

Objectives: The principal aim of this study was to compare the concentrations of gaseous pollutants emitted in enclosed pig buildings between different rates of general ventilation and determine the variations in the patterns of gaseous pollutants as affected by ventilation rate. Materials and Methods: The experiment was performed in the growing/finishing room($20.0m{\times}12.0m{\times}3.0m$) of a pig confinement building located on the experimental farm of Seoul National University. The conditions of the general ventilation rate for three treatments were 30%($4.12m^3s^{-1}$), 50%($6.87m^3s^{-1}$) and 70%($9.61m^3s^{-1}$). The data presented in the study were collected overa total of 45 days, 15 days for each of the three treatments from March to May 2011. A total of six air samplings were taken at 1.5m above the floor of the pig building. The environmental agents measured in the pig building were ammonia, hydrogen sulfide and odor concentration index for gaseous pollutants with temperature and hydrogen sulfide for thermal factors. Results: There were significant differences in the ammonia and odor concentration index in the pig building among the three general ventilation rate conditions(p<0.05), whereas hydrogen sulfide did not show a significant difference among three conditions of general ventilation rate(p>0.05). As the general ventilation rate applied to the pig building increases, it appears that all the indoor environmental agents measured in this study simultaneously decrease. Conclusions: The gaseous pollutants significantly affected by the general ventilation rate in pig building were ammonia and odor concentration index(p<0.05). However, it was found that hydrogen sulfide and thermal factors, temperature and relative humidity were not influenced significantly by variation in the general ventilation rate.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.77-80
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• 2001

Groundwater, contaminated predominantly with aromatic compounds and chlorinated ethylene, could be biologically treated in a fluidized-bed reactor with immobilized cells. The decomposition efficiency for the aromatics was over 90% at the retention time of 2.5 h. The chlorinated ethylenes, especially trichloroethylene (TCE) and cis-dichloroethylene (DCE), could be decomposed only insufficiently. No anaerobic methane formation was observed for this groundwater even at a very low dissolved oxygen (DO) concentration of 0.75 mg/L. The variation of DO concentration resulted in an optimal value of 1.5 mg/L. The recycle of air waste could increase the utilization of oxygen. The amount of low boiling pollutants stripped out remained constant with the recycle, while for the higher boiling pollutants the stripping slightly increased. Using air instead of oxygen increases the flow rate of air waste, which is connected to a higher stripping of pollutants. In this investigation, the pollutant concentration in the air waste remained constant. The stripping of main pollutants did not exceed 0.3 %.

• 환경위생공학
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• 제9권2호
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• pp.8-23
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• 1994

During the period from Mar., 1991 to Feb., 1992 66 tSP samples were collected by Hi volume air sampler at 1 sampling site in Seoul and the amount of concentration of 21 components(SO$_{4}$$^{2-}$, NO$_{3}$$^{-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Al, Ba, Ca, Cd, Cr, Cu, Fe, It Mg, Mn, Na, Ni, Pt Si, Ti, Zn, Zr ) were measured. And monthly and seasonal variation were surveyed and the principal component analysis( PCA ) were carried out with respect to these amount of pollutants, minimum of visibility and radiation on a horizontal surface. The total amount of soluble ion in water was high in order o(SO$_{4}$$^{2-}$> NO$_{3}$$^{-}$> N%'>Cl$^{-}$ and metal ion was high in order of Na> Ca>Si> Fe> Al> K> Mg> Zn> Pb> Cu>Ti> Mn > Ba> Cr> Zr> Ni> Cd. There was Seasonal variation in concentration for SO$_{4}$$^{2-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Na, Al, Ca, Bt Mg, Fe and Si. It was assumed that the components of the highest concentration on April were depend on yellow sand and the frequency of wind velocity and direction. As the results of PCA, the amount of pollution components was able to characterized with two principal components(Z$_{1}$, Z$_{2}$ ). The first principal components Z$_{1}$ was considered to be a factor indicating the pollutants originated from natural generation and The second principal components Z$_{2}$ was considered to be a factor indicating the pollutants originated from human work. The monthly concentration of pollutants in ISP, minimum of visibility and radiation on a horizontal surface was possible to evaluate by the use of these two principal components Z$_{1}$ and Z$_{2}$ .

• 한국환경보건학회지
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• 제31권3호
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• pp.215-220
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• 2005

The atmospheric transportation and dispersion processes of air pollutants are important issues in dealing with air pollution problems. Air pollutants originated from biological and anthropogenic activities are not only limited to the local emission sources, but could also be transported and dispersed to other regions by synoptic weather systems. Besides, the complexity of topography of central Taiwan helps accumulating air pollutants to promote high-concentration episodes. The techniques of tethersonding were applied to monitor the vertical profiles of winds, air temperatures and humidity, as well as to collect air samples, to be analyzed for pollutants $(O_3,\;NO_2,\;NO\;and\; NMHC)$ from the ground up to 1000m. A time period of about one week, 19-26 October 2002, was chosen as the sampling period due to the high frequency of episode occurrence in autumn based on the past records. Associating with the analysis of weather patterns, the atmospheric characteristics over high-concentration areas can be resolved in more detail. The result of the tethersonding studies showed that weak northerly sea breeze (with thickness about 300m) with low wind speed (about 1 to 2 m/sec) could help develop high ozone concentrations in the down-wind areas. It is also important to have a built-up aloft of precursors and ozone to develop high concentration on the previous day.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.184-210
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• 2005

The atmospheric transportation and dispersion processes of air pollutants are important issues in dealing with air pollution problems. Air pollutants originated from biological and anthropogenic activities are not only limited to the local emission sources, but could also be transported and dispersed to other regions by synoptic weather systems. Besides, the complexity of topography of central Taiwan helps accumulating air pollutants to promote high-concentration episodes. The techniques of tethersonding were applied to monitor the vertical profiles of winds, air temperatures and humidity, as well as to collect air samples, to be analyzed for pollutants ($O_3,\;NO_2$, NO and NMHC) from the ground up to 1000 m. A time period of about one week, 19 -26 October 2002, was chosen as the sampling period due to the high frequency of episode occurrence in autumn based on the past records. Associating with the analysis of weather patterns, the atmospheric characteristics over high-concentration areas can be resolved in more detail. The result of the tethersonding studies showed that weak northerly sea breeze (with thickness about 300 m) with now wind speed (about 1 to 2 m/sec) could help develop high ozone concentrations in the down-wind areas. It is also important to have a built-up aloft of precursors and ozone to develop high concentration on the previous day.