• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.62-71
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• 2012

Lake Doam watershed was surveyed to evaluate non-point source discharge characteristics and discharge load including several water quality parameters in Song Stream from July 2009 to July 2011. Concentrations of water pollutants were high during the rainfall period, especially, SS, TP and COD showed increasing tendencies toward cumulative water discharge but TN did not show much difference. SS, TP and COD had an initial flush effect of over 50 mm rainfall event but there was no clear tendency for rainfalls below that level. Event mean concentration (EMC) regarding the rainy and dry period showed large differences. Especially rainy season EMC (SS, TP, COD) demonstrated an increasingly high tendency. EMCs of COD, SS, TN and TP measured for twelve rain events were as high as 26.1, 866.0, 4.68 and 0.605 mg $L^{-1}$, respectively. COD, SS, TN and TP loadings from the highland agricultural region of the Song Stream watershed were 34,263, 1,250,254, 2,673 and 933 kg $yr^{-1}\;km^{-2}$, respectively, which were relatively higher than the results of other stream systems. Therefore, it is strongly recommended that long-term monitoring and non-point pollution reduction programs for the highland agricultural area to continue. Furthermore, this non-point source pollution loading research acquired from the highland agricultural area could be the base for reassessment.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.314-320
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• 2006

Diffuse pollution from an urban area contributes to the significant pollution loading to a receiving water body. In this paper, rainfall runoffs from an urban basin with combined sewer systems located in the city of Daejeon were monitored to measure the rainfall runoff discharge rates and pollutant concentrations. Strong first flush effects were observed for all monitored rainfall runoffs. The first flush effects were closely related to rainfall intensity, while suspended solids were closely related to pollutant constituents. The observed averaged Event Mean Concentrations (EMCs) of Combined Sewer Overflows (CSOs) were 536.1 mg SS/L, 467.7 mg CODcr/L, 142.7 mg BOD/L, 16.5 mg TN/L, and 13.5 mg TP/L. Storage volumes for containing the first flush to improve water quality of the receiving stream can be estimated based on suspended solid concentration. In this study, retainment of the first flush equivalent to 5mm of precipitation could reduce diffuse pollution loading induced by CSOs to a receiving water body by up to 80% of suspended solid loading.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.3
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• pp.92-100
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• 1996

In order to control the water quality in rivers or lakes, it is needed to evaluate accurate amount of pollutant loadings from watersheds. The daily pollutant loadings were simulated using the pollutant loading calculation model which was composed of mathematical equations superimposed on the TANK model. The calibration of runoff and pollutant loading parameters were carried out with observed data, using a trial-and-error method. In addition, the proposed model was applied to evaluate its applicability for the representative watershed, the Bokha river watershed, Icheon city, Korea. The parameters of SS and T-P showed large values in the first tank while T-N showed large in the second tank. As a result of simulating the daily pollutant loadings by the pollutant loading calculation model, all of SS, T-N and T-P loadings were increased or decreased according to the amount of runoff discharge. Especially, it was apparent that SS and T-P loadings were significantly influenced by the runoff variation when it was rain. These results could partly explain that SS and T-P would occur mainly from the surface runoff while T-N would occur from both surface and subsurface flow.

• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.450-457
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• 2016

The Total Maximum Daily Load (TMDL) is a watershed management system that involves the establishment of the target water quality, the calculation of permission loading (allocation loading), and the control of total pollutants for each unit watershed. Allocation loading is assessed through the comprehensive implementation assessment of the previous year's plan. Assessment results are used for follow-up management measures such as the limit of development and updating of TMDL Management Implementation Plans for the next planning period. Although detailed assessment criteria are important, they are not currently available. Therefore, we suggested assessment criteria by comparing two methods('integration method' and 'separation method') using combination point and non-point discharge loading. We also examined the penalty criteria considering controllable load local government and updating methods of the TMDL Management Implementation Plan for the next planning period.

• Environmental Engineering Research
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• v.11 no.3
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• pp.134-142
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• 2006

The treatment of high-strength swine wastewater by anaerobic digestion combined with an aquatic plant system was investigated. Anaerobic digestion of swine wastewater gave volatile solids (VS) removal efficiencies of 43.3%, 52.1% and 54.5% for hydraulic retention times (HRTs) of 20, 30, 40 days, respectively. The removal efficiencies of VS, total chemical oxygen demand (TCOD) and soluble chemical oxygen demand (SCOD) decreased with increasing VS volumetric loading rate (VLR). Higher organic removal efficiency was observed at longer HRTs for the same VS volumetric loading rate. As VS volumetric loading rate increased, biogas production increased and the methane content of the biogas decreased. Experiments using duckweed (Lemna species) as an aquatic macrophyte gave the following results. In the case of nitrogen, removal efficiency was above 60% and effluent concentration was below 10.0 mg/L when the influent ammonia-N loading was about $1.0\;g/m^2/day$. In the case of phosphorus, removal efficiency was above 55% and effluent concentration was below 2.0 mg/L when the influent $PO_4$-P loading was about $0.15\;g/m^2/day$. In addition, crude protein and phosphorus content of duckweed biomass increased from 15.6% to 41.6% and from 0.8% to 1.6%, respectively, as the influent nutrient concentration increased. The treatment of high-strength swine wastewater by anaerobic digestion combined with an aquatic plant system offers good performance in terms of organics and nutrient removal for relatively low operation and maintenance costs. The results indicate that under appropriate operational conditions, the effluent quality is within the limits set by Korean discharge criteria.

• KCID journal
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• v.9 no.2
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• pp.59-67
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• 2002

Considering complexity of industry and environmental surroundings of Geum river basin, factors of environmental pollution are very complicated and multi-changed. It is very needed to survey the discharge, water quality change and pollutant loading from up

• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.648-658
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• 2014

We examined the effects of pollutants into sub-basin on the water quality and loading based on data surveyed during January-December 2013 from 13 sites of 5 streams in the Jinwi watershed. We used the contour plot and Kruskal-Wallis rank sum test to analyze seasonal variation of water quality and loading and Pearson correlation analysis to assess the relationships between pollutants and loadings. The significantly higher seasonal variation were SS, TN and TOC as compared to other water quality constituents (P < 0.001). A significant interaction existed between the effects of human population and the effects of discharge of Sewage Treatment Plant (STP) on water quality and loading, especially for the spring and winter seasons. It is necessary to control discharge water of sewage and wastewater from industrial facilities and to make full use of the watershed management system such as TMDLs in operation since 2012 for improvement in stream water quality.

• Journal of Korean Society on Water Environment
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• v.29 no.4
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• pp.523-530
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• 2013

This study has been carried out to clarify the characteristics of discharge and pollutant loading according to flow conditions at jiseok stream watershed (JSW). A flow rate and pollutant load in the study watershed were estimated by equation of stage-discharge and discharge-loads rating curve. By using the methods above, I've evaluated the water quality (WQ) of the JSW if it is satisfied with the standard target. I've collected the data of BOD and T-P from the JSW every 8 days for the duration of 12 months. And then, I've schematized the data upon the load duration curve and the results showed me that the WQ of JSW was satisfied with the standard target. I've also collected the same data every each day for the duration of 12 months from JSW and have schematized the data again. And the results showed that it also was satisfied with the standard target. To be concluded, I've determined that point pollution sources of JSW gives more significant impacts to the WQ than non-point pollution sources of JSW and hence, as time goes, point pollution sources will keep depriciating the WQ of JSW. Therefore, further efforts will be required to JSW to maintain the WQ.

• Korean Chemical Engineering Research
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• v.45 no.5
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• pp.455-459
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• 2007

Plasma catalytic methane conversion was carried out in the presence of sol-gel derived $Pt/TiO_2$ catalysts within a dielectric-barrier discharge (DBD) reactor. Plasma-assisted reduction (PAR) was applied to reduce the prepared $Pt/TiO_2$ catalysts in DBD reactor, and prepared catalysts were successively reduced by PAR within 20 min irrespective of the Pt loading and the calcination temperature. The highest methane conversion was 40% when 3 wt% $Pt/TiO_2$ and 5 wt% $Pt/TiO_2$ catalysts were used after calcination at $600^{\circ}C$. The selectivities of light alkanes ($C_2H_6$, $C_3H_8$, $C_4H_{10}$) were highly increased when $Pt/TiO_2$ catalysts were used in DBD reactor.

• Journal of the Korean Geosynthetics Society
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• v.6 no.2
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• pp.1-8
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• 2007

Recently, the demand for industrial and residental land are increasing with economic growth, but it is difficult to acquire areas for development with good ground condition. For efficient and balanced development of land, new development projects are being carried out not only the areas with inland but those with the soft ground as well. As soft grounds have complex engineering properties and high variations such as ground subsidence especially when their strength is low and depth is deep, we need to accurately analyze the engineering properties of soft grounds and find general measures for stable and economic design and management. Vertical drain technology is widely used to accelerate the consolidation of soft clay deposits & dredged soil under pre-loading and various types of vertical drain are used with there discharge capacity. Under field conditions, discharge capacity is changed with various reason, such as soil condition, confinement pressure, long-term clogging and folding of vertical drains and so on. Therefore, many researcher and engineer recommend the use of required discharge capacity. In this paper, the experiment study were carried out to obtain the discharge capacity of four different types of vertical drains by utilizing the large-scale model tests and the required discharge capacity was calculated by several methods.