• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.179-180
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• 2015

The variety of organic and inorganic pollutants are introduced to coastal sediment and making highly contaminated due to rapid development of industralization and economic development. Numerous contaminants are release into marine sediment and it significantly affect marine aquatic environment. In the present study stated the optimize the biostimulant ball (BSB) in coastal sedimentand stabilse the heavy metals present in the sediment. The effective variables like BSB size, distance and month variables on Cu stabilization was determined by using Response surface methodology(RSM). The analysis of variance (ANOVA) and coefficient determination (R2) of Cu reduction 0.9610 and maximum stabilisation was obtained in 3cm ball size and 5.5cm distance and 4 month interval time. This result revealed that the BSB in effective for Cu reduction in coastal sediment.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.115-119
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• 2003

Pollutants from industry, mining, agriculture, and other sources have contaminated sediments in many surface water bodies. Sediment contamination poses a severe threat to human health and environment because many toxic contaminants that are barely detectable in the water body can accumulate in sediment at much higher levels, the purpose of this study was to make convenient sampling method and optimal treatment of sediment for water quality improvement in reservoir or stream based on an evaluation of degree of contamination. Results for analysis of S-reservoir sediments were observed that copper concentration of almost areas were higher than the regulation of soil pollution (50 mg/1) for the riverbed. S-stream sediments were observed that copper, arsenic and TPH concentration of almost areas were exceeded soil pollution concerning levels for factorial areas. We used Remscreen(version. 1.0) program which is contaminated soil recovery program to select optimal treatment method of contaminant sediments. The result was shown in the order of Thermal Calcination > Excavation, Retrieval and Off-site Disposal(comparative less then contaminant) > Low Temperature Thermal Desorption + Solidification/Stabilization.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.87-88
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• 2014

The Coastal sediment is highly contaminated due to ship transportation, industries discharges and urban sources. Various contaminants release into seawater and settle in marine sediment and it significantly affect marine eco system. In the present study evaluated the optimization of slow release biostimulant ball (BSB) in coastal sediment in busan. The effective variables like BSB size, distance and month variables on VS reduction was determined by using Response surface methodology(RSM). The analysis of variance (ANOVA) and coefficient determination (R2) of VS was 0.9369 and maximum reduction of VS was obtained in 3cm ball size and 5.5cm distance and 4 month interval time. This result revealed that the BSB in effective VS reduction in coastal sediment.

• Korean Journal of Microbiology
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• v.25 no.3
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• pp.229-237
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• 1987

To determine the characteristics of heterotrophic bacterial community in estuarine ecosystem, water and sediment samples were taden from Naktong estuary. All isolates were compared with 73 characters and described by cluster analysis. With same characters, 30 reference strains were able to divide into approximate species level at 80% similarity (S value). Diversity indices ($H^{1}$) of sediment column isolates were higher than water column isolates. The bacterial community commonly appeared in water and sediment column was reduced with going to downstream. Tolerance indices for temperature (Pt) and salinity (Ps) were also higher in sediment isolates than in water isolates. The bacterial community in sediment column is believed to be composed with diverse populations compared to water column and maintains its stability against various environmental changes with high physiological tolerances.

• Journal of the Korean Society of Hazard Mitigation
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• v.1 no.3 s.3
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• pp.93-102
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• 2001

In this study, the characteristics of river bed profile fluctuation are become possible to be used effectively in future estimation of Taehwa river general development plan through analysis and examination according to the effects of sediment protection weir located in the area of the estuary of Taehwa river's main channel using HEC-6 model. The flow conditions needed in analysis of the characteristics of river bed profile fluctuation refer the conditions of flow which secures 95 days in a year, flood flow, and design flood examined in the estimation of Taehwa river maintenance basic plan. First, in analysis result of river bed variation range, there is no significant variation in upstream section from Samho-gyo while there are the more active erosion and sedimentation as the more flow in downstream from Samho-gyo. Next, from the result of the capacity of sediment transfer, it is analyzed that sediment transfer capacity in the area of estuary of Taehwa river has no significant difference in before and after removal of the sediment protection weir when design flood flows while it is estimated that the more flow, the bigger sediment transfer capacity. Therefore, it is thought that the installation of a suitable hydraulic structure at the lowest point of Dong-chun tributary joins from the downstream of Taehwa river can be a good device to reduce the accumulation of sediments at the lowest point of Taehwa river considering the reduction plan of sediment inflow caused by removal of the sediment protection weir.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.1
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• pp.49-58
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• 1984

This paper is to exhibit the numerical analysis of sediment transport in the slowly varing flow and the sediment transport relation between the steady and the unsteady flow in the alluvial stream. The gradually varied flow of alluvial stream and the sediment transport are very complicated physical phenomen. Therefore the mathematical modeling is needed to be established. Linear implicit means of modified indirect method are applied to sediment transport by numerical analysis instead of the conception of steady flow in order to decrease errors. Further more, this study has purpose on reasonable prediction of the river-bed variation by way of this numerical method.

• Journal of Environmental Science International
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• v.19 no.10
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• pp.1219-1227
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• 2010

In this study, the sensitivity analysis of bed changes due to the various sediment transport equations have been conducted for 80 km reach of the Lower Nakdong River using the HEC-6 which is one dimensional numerical model. The bed elevation changes according to the different sediment transport formulas were compared and analyzed quantitatively. As a result of the numerical simulation, the final bed elevation calculated by Engelund and Hansen(1967), Ackers and White(1973), and Yang(1979) formulas was similar to one another in configuration. The bed change simulated by Engelund and Hansen(1967) were greatest among them, for example, 5.5 m deposition and 2.9 m erosion for 100 years. Also, in the case of Toffaleti (1969) equation, the maximum bed deposition of 8.04 m after 100 years was induced at the 73 km location upstream of the Nakdong River Estuary Barrage. Meyer-Peter-M$\ddot{u}$ller(1948) and Wilcock(2001) formulas produced the deposition only at the upstream end and there was little bed change in the downstream area. The unreal bed configuration of continuously up and down pattern was simulated by Laursen(1958) transport equation.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.2
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• pp.27-35
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• 2012

Various Best Management Practices (BMPs) have been suggested to reduce Nonpoint source pollutant loads from agricultural fields. However, very little research regarding water quality improvement with sediment trap has been performed in Korea. Thus, effects of sediment trap were investigated in this study. Three sediment traps were installed at the edge of six plots and flow and water quality of inflow and outflow were monitored and analyzed. It was found that approximately 64.1 % of flow reduction was observed. In addition, pollutant concentration of outflow was reduced by 39.0 % for $BOD_5$. For SS, $COD_{Mn}$, DOC, T-N, T-P, approximately 62.1 %, 43.4 %, 43.5 %, 40.0 %, and 41.2 % reduction were observed, respectively. Over 80 % and 90 % of pollutant loads were reduced from sediment trap #2 and #3 because of less outflow from plots covered with rice straw/straw mat. In case of intensive rainfall events occurred from July 26~29, 2011, over 60 % of pollutant and 88.9 % of sediment reduction were observed from sediment trap #3. As shown in this study, small sediment traps could play important roles in reducing pollutant loads from agricultural fields. If proper management practices, such as rice straw/straw mat, are used to protect surface from rainfall impacts and rill formation, much pollutant reduction could be expected.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.744-753
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• 2017

The sediment delivery ratio (SDR) is widely used to estimate sediment loads by multiplying soil loss through the Revised Universal Equation (RUSLE). In this study, the SDR equation was developed for the Lake Imha watershed using soil loss calculated by RUSLE and sediment loads by the calibrated Hydrological Simulation. Program Fortran (HSPF). The ratio of watershed relief and channel length ($R_f/L_{ch}$), the ratio of watershed relief and watershed length ($R_f/L_b$), curve number (CN), area (A), and channel slope ($SLP_{ch}$) demonstrated strong correlations with SDR. SDR equations were developed by a combination of subwatershed parameters by referring to the correlation analysis. The area based power functional SDR developed in this study showed significant errors at the point right after entering major tributaries, because SDR was unrealistically reduced when the watershed area increased significantly. The $SLP_{ch}$-based power functional SDR also showed extraordinary values when the channel slope was gradual. The SDR equation that showed the highest value of the coefficient of determination also presented unrealistic changes in the sediment loads within a relatively short river distance. The SDR equation $SDR=0.0003A^{0.198}R_f/L{_w}^{1.167}$ was recommended for application to the Lake Imha watershed. Using this equation, sediment loads at the outlet of the Lake Imha watershed were calculated, and the HSPF parameters related to sediment in the uncalibrated subwatersheds were determined by referring to the sediment loads calculated with the SDR equation.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.338-341
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• 2002

This work is the basis research to apply Hydrocyclone for the separation and the thickening to the reservoir sediment. Chemical analysis result showed that organic contaminants were abundantly found in smaller sediment particles. As a result of the experiment device that higher reduced efficiency was obtained under the high velocity and low concentration with the small cyclones.