• Journal of Wetlands Research
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• v.14 no.2
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• pp.159-168
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• 2012

Stormwater runoff affects the quality of surface water and groundwater due to the nonpoint sources (NPSs) of pollutants that it carries during storm events. Typically, urbanized areas experience high pollutant mass emission because of paved roads and other areas which are all highly impervious. For this reason, proper identification of the levels of pollutants from the watershed area is important to pass the Ministry of Environment of the Republic of Korea's water quality standards in rivers and streams. This research was conducted in order to determine and quantify the different constituents present in stormwater runoff generated from highly impervious areas in Cheonan City, Korea. Also, the average event mean concentration (EMC) of stormwater runoff from paved areas was compared with EMCs of other countries to determine the possible causes of its occurrence. In addition, the occurrence of first flush phenomenon was studied in order to find the first flush criteria to be used on the design of best management practices. The results show the pollutant concentration of stormwater runoff was higher than other countries due its landuse and relatively small size of catchment area. During the first 30 minutes of the rainfall events, occurrence of first flush phenomenon was highly evident. Several factors affected the pollutant concentrations in the stormwater such as landuse type, geographic and topographic characteristics,catchment area and amount of rainfall. This research can provide guidance in achieving an effective NPS pollution management applicable to highly urbanized areas in the future.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.3
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• pp.83-96
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• 2017

This study presented a surface water quality modeling framework considering the spatial resolution of pollutant load estimation to better represent stream water quality characteristics in the Saemangeum watershed which has been focused on keeping its water resources sustainable after the Saemangeum embankment construction. The watershed delineated into 804 sub-watersheds in total based on the administrative districts, which were units for pollutant load estimation and counted as 739 in the watershed, Digital Elevation Model (DEM), and agricultural structures such as drainage canal. The established model consists of 7 Mangyung (MG) sub-models, 7 Dongjin (DJ) sub-models, and 3 Reclaimed sub-models, and the sub-models were simulated in a sequence of upstream to downstream based on its connectivity. The hydrologic calibration and validation of the model were conducted from 14 flow stations for the period of 2009 and 2013 using an automatic calibration scheme. The model performance to the hydrologic stations for calibration and validation showed that the Nash-Sutcliffe coefficient (NSE) ranged from 0.66 to 0.97, PBIAS were -31.0~16.5 %, and $R^2$ were from 0.75 to 0.98, respectively in a monthly time step and therefore, the model showed its hydrological applicability to the watershed. The water quality calibration and validation were conducted based on the 29 stations with the water quality constituents of DO, BOD, TN, and TP during the same period with the flow. The water quality model were manually calibrated, and generally showed an applicability by resulting reasonable variability and seasonality, although some exceptional simulation results were identified in some upstream stations under low-flow conditions. The spatial subdivision in the model framework were compared with previous studies to assess the consideration of administrative boundaries for watershed delineation, and this study outperformed in flow, but showed a similar level of model performance in water quality. The framework presented here can be applicable in a regional scale watershed as well as in a need of fine-resolution simulation.

• Journal of the Korean GEO-environmental Society
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• v.17 no.5
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• pp.27-36
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• 2016

Low Impact Development (LID) techniques are eco-friendly storm water management process for water circulation restoration and non-point pollutant reduction. In this study, four LID techniques (Small constructed wetland, Infiltration trench box, Infiltration trench, Vegetated swale) were selected and installed as a real size at the real site. All facilities were evaluated as monitoring under the real environmental climate situation and an artificial rain with exceeding design rainfall. In various rainfall, runoff reduction efficiency and non-point pollutant removal efficiency are increased to the bigger Surface Area of LID (SA)/Catchment Area (CA) ratio and the bigger Storage Volume of LID (SV)/Catchment Area (CA) ratio. Runoff did not occur at all rainfall event (max. 17.2 mm) in infiltration trench and vegetated swale. But Small constructed wetland was more efficient at less than 10 mm, a efficiency of infiltration trench box was similar at different rainfall. Although different conditions (such as structural material of LID, rainfall flow rate, antecedent dry periods), LID techniques are good effects not only water circulation improvement but also water quality improvement.

• Journal of environmental and Sanitary engineering
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• v.23 no.4
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• pp.55-64
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• 2008

In this study, the management and improvement of public small-scale sewage treatment facilities was investigated. In order to improve the effective management of the operation of small-scale sewage treatment facilities, treatment methods and the problems associated with sewage treatment were carefully addressed based on the data and literature. The investigation results showed that sewer pipes in rural areas should be repaired to prevent sewage from leaking and small-scale operations should be required to have effective management for pollutant loads less than 50%. Also, new methods should be developed for low concentrations of sewage. A law associated with FRP treatment facilities should be established and local governments need to supervise these operations to avoid insufficient and faulty construction. It is recommended that new facilities are built with advanced treatment techniques when the old facility can not comply with nitrogen and phosphorous discharge limits. Moreover, the study shows that nutrient and coliform treatment efficiency improves when abandoned facilities are renovated with the installation of nitrification/denitrification and disinfection processes or another advanced process.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.807-814
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• 2006

Sapkyo Lake Watershed occupies about 19.3% of total area of Chungnam Province, and it is necessary to make a plan of counter-measure for the maintenance of public waterbody sound as well as to ensure water resources due to urbanization and industrialization in this area so densely populated and excessively developed. Conventionally water quality management has been enforced by concentration-based system which is not considered the carrying capacity of receptors, hence there are no proper measures for the prevention of an excessive pollutant load over a waterbody. So even though emission sources abide by the conventional permission regulation, then the quantity of wastewater is increased continuously and encountered water shortage to use finally. Therefore this research focused on the review of introduction of total water quality management system in Sapkyo Lake watershed to maintain public waterbody sound and to ensure water resources. By doing this research in introduction of the system in advance, it can contribute to establish the methodology on systematic water quality management. Also the application of this system in Sapkyo Lake watershed can promote the sustainable development of the area by harmonizing the environment and regional economy ultimately.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.465-468
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• 2002

Land application is one of the desirable management practices for animal wastes. Majority of livestock farms adopt composting and land applications for the management of animal waste in this country. Meanwhile, there are only a few studies related with the effects of land application on pollutant loading. This study investigates the water quality characteristics in a rural watershed with intensive livestock farming. The results indicate that major constituents of water quality are substantially increased at the sites near livestock farms and compost incorporated fields during the rainfall-runoff periods. There are no significant differences of water quality parameters among the sampling sites during no rain periods.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.754-758
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• 2008

This study establishes management plan for water quantity and quality using PCSWMM and alternative evaluation index (AEI). PCSWMM can consider combined sewer overflows (CSOs) and simulate not only the flowrate but aslo the pollutant of BOD, SS, TN and TP for the effectiveness analysis of alternatives. Indicators of AEI are selected using sustainability evaluation concept, driver-pressure-state-impact-response (DPSIR) model and calculated by weighted summation method. These were applied for the Mokgancheon watershed which has many combined sewers. This result will be effective to the integrated watershed management for sustainability.

• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1031-1037
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• 2006

In order to improve water quality of the Juam Lake, a constructed wetland was implemented and operated for 2 years with the effluent of sewage treatment plant and diffuse pollutant discharged from agricultural area. During the summer season, average removal efficiencies for BOD and SS were 15.8% and 39.4%, respectively. Due to the mixed effect of vegetation, soil microbes and sediments, the higher nutrient removal efficiencies were obtained: average T-N and T-P removal efficiencies were 64.2% and 71.7%, respectively. The concentration of sediment was increased initially, and maintained constant throughout monitoring period. The highest nitrogen and phosphorus uptake were observed in Phragmites japonica. The nitrogen uptake was estimated as 0.235 DW mg/g while phosphorus uptake was estimated as 2.059 DW mg/g.

• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.51-60
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• 2002

Concerning the water quality management plan about Buk-stream, Ohsip-stream and Gagok-stream water systems in this research, which objectives of abstract is as follows. The result of cleanness degree evaluation of water quality in this research, the first grade was 91% shared in Buk-stream water system. The most point of the middle and upper stream of Buk-stream was maintain extremely clean water quality. Among the researched water system, the first grade of water quality in Ohsip-stream water system was most poor, its first garde rate was 68%. In all water quality check point of Gagog-stream water system was accomplished extremely clean water quality condition of first grade of BOD. The calculation result of pollutant loading density, which were 8.2, 21.5, 4.0kg/day.$\textrm{km}^2$. respectively and basin of Buk-stream and Gagok-Stream have high development potentiality.

• Proceedings of the Safety Management and Science Conference
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• 2013.11a
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• pp.547-560
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• 2013

In this study, the air pollutant removal such as sulfur oxides was studied. A combination of the plasma discharge in the reactor by the reaction surface discharge reactor Calcium hydroxides catalytic reactor and air pollutants, hazardous gas SOx, changes in gas concentration, change in frequency, the thickness of the electrode, kinds of electrodes and the addition of simulated composite catalyst composed of a variety of gases, including decomposition experiments were performed by varying the process parameters. The experimental results showed the removal efficiency of 98% in the decomposition of sulfur oxides removal experiment when Calcium hydroxides catalysts and the tungsten(W) electrodes were used. It was increased 3% more than if you do not have the catalytic. If added to methane gas was added the removal efficiency increased decomposition.