• Journal of Environmental Science International
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• v.16 no.3
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• pp.333-345
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• 2007

As analyzed the estimated values of the daily delivery loads from thirteen major side streams such as Naesung-river, Keumho-river, Hwang-river, Nam-river during five years (from 1999 to 2003), the daily BOD inflow into the main stream of Nakdong river in 2003 shows the highest quantity as 31.1 ton and the daily BOD inflows in 1999, 2000, 2001, and 2002 are 26.7 ton, 22.5 ton, 21.0 ton, 25.8 ton, respectively. The daily TN in-flow into the main stream of Nakdong river in 2003 shows also the highest quantity as 64.9 ton and the daily TN inflows in 1999, 2000, 2001, and 2002 are 55.19 ton, 46.27 ton, 39.5 ton, 53.38 ton, respectively. The daily TP inflow into the main stream of Nakdong river in 2003 shows the highest quantity as 2.70 ton likewise and the daily TP inflows in 1999, 2000, 2001, and 2002 are 2.17 ton, 1.87 ton, 1.60 ton, 2.10 ton, respectively The rate of BOD loads from each side main stream into the main stream of Nakdong river shows that the BOD loads of Keumho-river are the highest as the values range from 32.8 % (2002) ${\sim}$ 35.1 % (2003) and the BOD loads of Nam-river, Naesung-river, Hwang-river are high in the order named. The rate of TN loads to the main stream is also similar to the trend of BOD loads. The contribution of the TN loads of Geumho-river to the contamination of the main stream is also the highest having a range from 27.0 % (2002) to 28.8 % (1999) among the main side streams and the TN loads of Naesung-river, Nam-river, and Heachun-river are high in the order named. The rate of TP loads is quite different from the trend of BOD and TN loads. The TP rate of Keumho-river, however, is still the highest as ranging 58.6 % (2002) to 61.7 % (2003) and the river has the biggest portion (over 50%) of the entire pollution to the main stream of Nakdong river.

• Journal of Environmental Science International
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• v.26 no.8
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• pp.881-891
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• 2017

In this study, the discharge loads of non-point pollution sources were analyzed using a Hydrologic Simulation Program-Fortran (HSPF) model for 46 sub-watersheds in order to guide the management plan for water and streams passing through the city. The results using HSPF showed good applicability in comparison to point measurements, which were based on BOD, TP, and TN. The mean value of the BOD loads was $4.08kg/km^2$ per day, and the highest level of BOD was $17.75kg/km^2$ per day at Namri. Three potential areas of high priority for the installment of constructed wetlands were selected in order to reduce non-point pollution sources based on BOD loads and on environmental and economic conditions. The results for these scenarios indicated a maximum rate of reduction in BOD of 39.12% within the proposed constructed wetlands.

• Journal of Korea Water Resources Association
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• v.40 no.8
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• pp.585-600
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• 2007

The hydrologic cycle and BOD pollutant loads of all sub-watersheds were analyzed using HSPF (Hydrological Simulation Program-Fortran). At first, sensitivity analyses to water quantity (peak discharge and total volume) and quality (BOD peak concentrations and total loads) were conducted and some critical Parameters were selected. For more precise simulation, the study watershed was divided into four parts according to the landuse characteristics and used climate data and so calibrated and verified respectively. It was found that as the urban area ratio increases in the downstream direction, baseflow decreases (11.1 % $\rightarrow$ 5.0%) and the ratio of direct runoff volume(42.5 % $\rightarrow$ 56.9 %), BOD concentration (3.3 mg/L $\rightarrow$ 15.0 mg/L) and unit loads (55.4 kg/ha/year $\rightarrow$ 354.5 kg/ha/year) increase.

• Environmental Engineering Research
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• v.25 no.1
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• pp.123-128
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• 2020

Non-point source pollutant load reductions were calculated using the Hydrologic Simulation Program-Fortran (HSPF) model under the assumption that landuse pattern was changed according to land purchases. Upon the simulation of non-point pollutant and areas with high land purchase ratios to select a buffer zone, the Namgang dam Reach 11, Imha dam Reach 10, and the Reach 136 watershed of the main river were found to rank high for the construction of buffer zones. Assuming that the forms of the purchased lands were changed to wetlands, biological oxygen demand (BOD) loads were changed through the HSPF model. No changes of BOD were present in the Namgang dam and the Imha dam watersheds. BOD loads in Reach 136 according to landuse change were analyzed through a flow duration analysis based on the total maximum daily loads of the United States. The flow duration analyses undertaken to examine changes in BOD of main river Reach 136 watershed indicated a shift of 0.64 kg/d from 3.16 to 2.52 during high flow. The change of BOD under the conditions of moist, mid-range and dry were 11.9%, 9% and 4.5%. At the low flow condition, the variation range in the BOD load was from 0.58 kg/d to 0.41 kg/d.

• Journal of Environmental Impact Assessment
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• v.12 no.5
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• pp.349-358
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• 2003

Water pollution of Hwanggujicheon stream is severe because urban area of Suwon City is included in the basin. A countermeasure for water quality prevention of the stream is necessary. In this study, nonpoint pollutant load of BOD, SS, TN and TP are estimated using SWMM. The result indicates that BOD, SS, TN and TP loads during 3 months from July to September are 67.0%, 60.8%, 54.7% and 74.5% of the annual total load, respectively. We can see that most of nonpoint pollutant loads are generated in the rainy season. Annual nonpoint pollutant loads of BOD, SS, TN and TP in the Hwanggujicheon stream are 342 ton, 1,500 ton, 480 ton and 12.6 ton, respectively.

• Wind and Structures
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• v.21 no.4
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• pp.425-442
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• 2015

This paper discusses the processing of the wind loads measured in wind tunnel tests by means of multi-channel pressure scanners, in order to compute the response of 3D structures to atmospheric turbulence in the time domain. Data compression and the resulting computational savings are still a challenge in industrial contexts due to the multiple trial configurations during the construction stages. The advantage and robustness of the bi-orthogonal decomposition (BOD) is demonstrated through an example, a sail glass of the Fondation Louis Vuitton, independently from any tentative physical interpretation of the spatio-temporal decomposition terms. We show however that the energy criterion for the BOD has to be more rigorous than commonly admitted. We find a level of 99.95 % to be necessary in order to recover the extreme values of the loads. Moreover, frequency limitations of wind tunnel experiments are sometimes encountered in passing from the scaled model to the full scale structure. These can be alleviated using a spectral extension of the temporal function terms of the BOD.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.277-287
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• 2006

Production loads of the contaminants near the Nakdong-river are, BOD : $1,006ton{\cdot}day^{-1}$, TN : $117ton{\cdot}day^{-1}$, and TP : $21ton{\cdot}day^{-1}$. Among the sources of contamination, the biggest contribution to the production load was shared by the human population, which maintains 40.7% of BOD, 44.2% of TN, and 52.5% of TP production. Similarly, among the sources of discharge load, the human population contributed 45.0% of BOD, 34.5% of TN, and 45.8% of TP. Results of flow investigation in 2001 and 2002 indicate that among the side streams, Nam-river showed the greatest average flow. In case of main stream flow, it was increased in the downstream due to the increase of the influents from the side streams. In case of BOD, COD, TOC and SS, high values were detected at Keumho-river where industrial wastewater was discharged as high level concentration. In case of the main stream, Koryoung point where direct influence of Keumho-river and Seongseo industrial complex is evident showed high BOD, COD and TOC. Oxidized nitrogen compounds and total nitrogen showed similar patterns of BOD, COD, and TOC. Especially, nitrate nitrogen was relatively high at all points. However, in case of Chlorophyll-a, relatively high values were observed at mid- and downstream areas such as Koryoung, Namjee, Soosan, Moolkeum and Hakooeun. This could be caused by the slow flow rate and the abundant nutrient salts attributed by the side streams. Relatively better water quality was observed in 2002 when the flow was relatively abundant than that in 2001. Results of investigation during 2001-2002 showed that delivery load increased as the flow reaches downstream. In 2001, delivery loads at the downstream Soosan-bridge were BOD $22,152ton{\cdot}day^{-1}$, COD $45,467ton{\cdot}day^{-1}$, TN $22,062ton{\cdot}day^{-1}$, TP $926ton{\cdot}day^{-1}$. Delivery loads in 2002 were increased due to the increase of the rainfall. They are BOD $25,876ton{\cdot}day^{-1}$, COD $64,200ton{\cdot}day^{-1}$, TN $41,101ton{\cdot}day^{-1}$, and TP $1,362ton{\cdot}day^{-1}$.

• Journal of Environmental Science International
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• v.22 no.4
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• pp.493-505
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• 2013

This study was to investigate the runoff characteristics of non-point pollutants source at the urban area in Suwon city. The highest T-N and T-P concentration of rainfall runoff observed in agricultural area. In residential area, the highest $BOD_5$ and SS concentration of rainfall runoff was investigated. During rainfall events, the peak concentrations of SS and $BOD_5$ were observed after 1~2 hours of rainfall in urban area. Whereas, the peak concentrations occurred within 1~2 hours after rainfall and then the highest concentrations of SS and $BOD_5$ sharply decreased, showing strong first flush effect in urban area. The EMC results indicated that the highest value of T-N and T-P in agricultural area was observed. While residential area was shown the lowest EMC value as T-N and T-P. Non-point pollutant loads on the land use types in urban area were investigated in the order of residential>industrial>agricultural>highway. $BOD_5$ and SS loads on urban watershed were investigated in the order of Suwon>Hwangguji>Seoho>Wonchunri. Whereas, T-N and T-P loads on urban watershed were investigated in the order of Hwangguji>Suwon>Wonchunri>Seho.

• Journal of Environmental Science International
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• v.2 no.2
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• pp.135-144
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• 1993

The purpose of this experimental research was focused to improve the quality of the effluent and the yielded sludge when the papermill wastewater was treated by the indirect aerated submerged biofilter as a second treatment method of papermill wastewater. Changing the various experimental factors (Nutrient additions or not, HRT, Fh ratio, recirculation ratio, etc) with indirect aerated submerged biofilter, the results are as follows. 1) because of the microbes concentration could be sustained to 9, oho man in submerged biofilter and then the volumetric organic loads could be increased to 2.7 kg-BOD/$m^3$<\TEX>/day, the reactor volume can be reduced. 2) Because of the yield coefficient(Y) and the endogenous decay coefficient(kd) were revealed 0.4 and 0.07/d, the yielded sludge volume was reduced. 3) The concentration of the sloughed sludge in the reactor was 2.62~4.01 %, so the thickener could be omited in the papermill wastewater sludge treatment process. 4) When the operating was conducted at HRT of 4hrs, the treatment efficiencies of BOD and COD were obtained 80% and 70%. 5) The range of the theoretical recirculation ratios of this reactor was 14~26. According to those ratios, at the low loads ( BOD volumetric loads is less than 0.79 kg-BOD/$m^3$<\TEX>/day, FM ratio is less than 2.0/d) the results were fitted to the theoretical recirculation ratios (14 ~26) and at the high loads the efficiency were increased to the rise of recirculation ratios.

• Journal of Korean Society on Water Environment
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• v.20 no.2
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• pp.151-156
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• 2004

A decision support system, Watershed Analysis Risk Management Framework(WARMF), was applied to the Kyungan Stream watershed, a tributary of Lake Paldang, for calculation of total maximum daily loads(TMDL). The WARMF system was developed by Systech Engineering, USA, and has been successfully used in several watersheds, for TMDL studies. The study area was divided into 14 sub-basins, based on digital elevation model(DEM). The integrated watershed and stream model of WARMF was validated by flow and BOD data measured during the year of 1999. There were reasonable agreements between model results and field data, both in water flow and BOD. The validated Kyungan WARMF was extensively utilized to study the quantitative relationship between waste loads and receiving water quality. Based on TMDL guideline at Paldang Lake and Kyungan Stream, the water quality criterion were set to be 3.0mg/L, 3.5mg/L, and 4.0mg/L at the watershed outlet. The allowable waste loads of BOD, both from point and non-point sources, were determined at each water quality criterion. From this study, it was concluded that the WARMF provided several advantages over the conventional application of watershed and stream models for TMDL study, such as time variable simulations, multiple possible soutions, and reduction loads for goal water quality, etc.