• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.648-653
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• 2010

Discharged pollution load for the management of Total Maximum Daily Loads (TMDLs) is calculated on the basis of rainfall data for reference year. Rainfall has an influence on discharged pollution load in unit watershed with combined sewer system. This study reviewed the status of discharged pollution load and rainfall conditions. We also investigated rainfall effects on discharged pollution load by analyzing change of the load in accordance with increase of rainfall. The change ratio of discharged pollution load was 18.6% while inflow load only 5.8% for 5 years from 2004 to 2008 in Daejeon district. The greatest rainfall and rain days were over 2 times than the least during the period. This change in rainfall could have great effect on discharged pollution load. The analysis showed that discharged pollution load increased 2.1 times in case rainfall increased 2 times and 1.2 times in case rain days increased 2 times. Rainfall effects, therefore, should be considered to make resonable evaluation of discharged pollution load in the assessment of annual performances.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.1008-1015
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• 2010

Discharged pollution load is varied as rainfall changes in the area with combined sewer system. Changes in discharged pollution load are directly related with those of sewer transfer flow. Therefore, it is important to identify the pattern of sewer transfer flow for the analysis of changes in discharged pollution load. This study reviewed the type of distribution of sewer transfer flow for 17 sewage treatment plants and developed simple formular to estimate sewer transfer flow as rainfall changes. 11 facilities showed to have some relation with rainfall in the change of sewer transfer flow but 6 facilities to have no relation. Relationships between rainfall amount and sewer transfer flow showed that 6 facilities out of 11 had relatively strong relationships above R2=0.5, which were considered to be affected directly by rainfall changes. The formular which explain the relationship between rainfall and sewer transfer flow can be applied in the analysis of rainfall effects on discharged pollution load, therefore, the more appropriate evaluation will be done.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.547-556
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• 2005

The objective of this study is to obtain adequate intercepting flow during wet weather conditions in combined sewer system. Two study sites are selected under considering different population density, one is developed area with heavy urbanization. Another is recently developing area. In the analysis of field investigation, SS was most significant in initial flushing effects compared with other factors and showed the result with the order of COD, TP, TN. As compared with event mean concentration(EMC) of runoff, BOD, TN and TP showed high concentrations in wide area with relatively large population density. It is by the reason that much pollution load was discharged to receiving water from urbanized area during wet period. According to results of storm-water modeling, 53% of total COD and 52% of total SS pollution load were discharged to receiving water by overflow than intercepting capacity in middle population density site. Also, in the urbanized area, pollution load was discharged to receiving water by 49% of total COD and 77% of total SS. These results can be applied to setup for pollution load flow(budget) generation, collection, treatment and discharging in order to obtain adequate intercepting flow.

• Journal of Korean Society on Water Environment
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• v.32 no.6
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• pp.589-599
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• 2016

Implemented since 2004, TPLC (Total Pollution Load Control) is the most powerful water-quality protection program. Recently, uncertainty of prediction using steady state model increased due to changing water environments, and necessity of a dynamic state model, especially the watershed model, gained importance. For application of watershed model on TPLC, it needs to be feasible to adjust the relationship (mass-balance) between discharged loads estimated by technical guidance, and arrived loads based on observed data at the watershed outlet. However, at HSPF, simulation is performed as a semi-distributed model (lumped model) in a sub-basin. Therefore, if the estimated discharged loads from individual pollution source is directly entered as the point source data into the RCHRES module (without delivery ratio), the pollutant load is not reduced properly until it reaches the outlet of the sub-basin. The hypothetic RCHRES generated using the HSPF BMP Reach Toolkit was applied to solve this problem (although this is not the original application of Reach Toolkit). It was observed that the impact of discharged load according to spatial distribution of pollution sources in a sub-basin, could be expressed by multi-segmentation of the hypothetical RCHRES. Thus, the discharged pollutant load could be adjusted easily by modification of the infiltration rate or characteristics of flow control devices.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.18-25
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• 2012

For effective watershed management, it is very important to select the tributaries through selection and concentration of targeted tributary catchments for improving water quality within the limited financial conditions. This study introduced the selection and diagnosis procedure of tributary catchments for improving water quality at Chungcheongnam-do based on water quality and flowrate monitoring, stream grouping method. The tributaries with high value of water quality and flowrate were selected for improving water quality according to stream grouping method. The diagnosis of selected tributaries for improving water quality was performed with analysis of the pollution load (generated, discharged, delivered) and point source discharged pollution load density. The plans for improving water quality of tributaries were suggested thorough various diagnosis of tributary catchments. For improving water quality of tributaries in Chungcheongnam-do, the tributary catchments in the Dangjin, Asan, Yesan, Cheonan, Hongseong area should be preferentially considered. The water quality improving plans for those tributary catchments, in accordance with the reduction of sources of pollution by population and livestock, should be established.

• KCID journal
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• v.17 no.2
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• pp.35-41
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• 2010

For efficient water quality management of Saemangeum lake, it is very important to accurately analyze discharged load characteristics using investigated pollution sources data from Saemangeum watershed. Investigation of pollution sources was conducted from 2003 to 2007. In this study, pollution sources are largely classified into human population, livestock, industry, and land use. Discharged loads of BOD, T-N and T-P from classified pollution sources were calculated by Korea TMDL (Total Maximum Daily Load) technical guideline. The calculated results showed that the major sources of BOD and T-N were land use, human population, livestock, and industry in order. However, the major sources of T-P were livestock, land use, human population, and industry in order. Our results clearly show that pollution sources of the priority management for water quality enhancement in the Saemangeum lake has represented land use and livestock.

• Journal of Environmental Impact Assessment
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• v.16 no.1
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• pp.79-87
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• 2007

The performance of a stream water quality analysis model depends upon many factors attributed to the geological characteristics of a watershed as well as the distribution behaviors of pollutant itself on a surface of watershed. Because the model run has to import the pollution load from the watershed as a boundary condition along an interface between a stream water body and a watershed, it has been used to introduce a pollution delivery coefficient to behalf of the boundary condition of load importation. Although a nonlinear regression model (NRM) was developed to cope with the limitation of a conventional empirical way, this an up-to-date study has also a limitation that it can't be applied where the pollution load washed off (assumed at a source) is less than that delivered (observed) in a stream. The objective of this study is to identify what causes the limitation of NRM and to suggest how we can purify the process to evaluate a pollution delivery coefficient using many field observed cases. As a major result, it was found what causes the pollution load delivered to becomes bigger than that assumed at the source. In addition, the pollution load discharged to a stream water body from a specific watershed was calculated more accurately.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.10
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• pp.719-723
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• 2014

For effective implementation of total maximum daily load (TMDL), this study presented the improving plans of non-point source pollution management including the classification of non-point source pollution, calculation of non-point source pollution load (generated, discharged), selection of non-point source pollution management regions and management of non-point source pollutant. First of all, the definition of point source pollution and non-point source pollution based on the legal and scientific viewpoint should be precisely classified and managed. Especially, the forest, grassland and river without occurrence of environmental damage by activity of business and human should be separately classified natural background pollutants. The unit for generated and discharged non-point source pollution should be preferentially changed according to actual condition of watershed. The calculation methods of generated and discharged non-point source pollution should be corrected consideration on the amount and duration of rainfall. While the TMDL is implemented, non-point source pollution management regions should be selected in the watersheds exceed the targeted water quality standards by the rainfall. The non-point source pollution management regions should be selected in the minimal regions where have high values of discharged non-point source pollution density in the urban area, farmland and site area except forest, grassland in the whole watershed. The non-point source pollutant treatment facilities, which take into consideration non-point source pollution load per unit area, duration of the excess concentration, realizable possibility of treatment, effectiveness of treatment cost versus point source pollutant, should be established in the regions with a large generated non-point source pollution load and a high concentration of water quality exceed the targeted water quality standards by the rainfall.

• Journal of Korean Society on Water Environment
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• v.32 no.4
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• pp.375-383
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• 2016

Total Pollution Load Control (TPLC) calculates and manages the allowable pollutant load that is discharged from the watershed, which can meet the water quality target. Delivery Ratio (DR) is generally used for predicting the variation of pollutant mass balance between the pollutants discharged from the watershed and a certain point in the stream, and it is very important for estimation of accurate allowable pollutant load. The concept of DR in TPLC is different from prevalent DR, because DR in TPLC includes both the discharge of pollutants from the watershed and the delivery mechanism. Therefore, DR in TPLC should be estimated by using a proper and unified methodology. The appropriate method and equation for estimation of DR in TPLC was developed through the review of various methodologies, and the applicability of the equation was evaluated in a study area (Geumho A). Determination coefficients (R²) of regression were shown to be relatively high (BOD 0.71~0.87, T-N 0.86~0.90, T-P 0.62~0.69). Applicability of the developed methodology and equations was evaluated as appropriate for TPLC, and it is suggested.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.670-675
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• 2000

The purpose of the study is development and investigation about basic performance of the system operation on a dual fueled cogeneration system(CGS), which is operated with biogas and gas oil. As often seen in dual fueled CGS performance, the electric generating efficiency was obtained about 26□. Methane contained in the biogas could not bum completely at lower load, and it was discharged into exhaust gas. Considerable amount of the methane burned in the exhaust pipe, and the heat recovery ratio was 42□ on heat balance. As a result, the total heat efficiency, which is a summation of generating efficiency and heat recovery efficiency reached to about 70□. The supply of biogas into the engine reduces smoke density and NOx concentration in exhaust gas. At lower load, methane burned slowly and large portion of it was discharged without burning. Therefore the measures are desirable that promotes combustion of methane at lower load.