• Journal of Korean Society of Water and Wastewater
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• v.18 no.4
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• pp.427-436
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• 2004

Sedimentation is one of the most common and important units in conventional water treatment plants. Structure such as various baffle walls and inclined plate settler may be obstacles to the horizontal flow when it is poorly designed. Therefore, the effects of these structures on characteristics of hydraulic flow must be evaluated to improve the settling efficiency of the floc. The hydraulic characteristic of the four sedimentations at the three real WTPs (water treatment plants), which have different structural properties respectively inside the settling basin, were investigated by tracer (fluoride) test. The inclined plate settler installed inside settling basin caused a undesirable impact on horizontal flow and produced dead zone. Intermediate baffle and solid baffle wall under the inclined plate settler at GE plant help to minimize the formation of density currents and flow short circuiting. However, installing perforated baffle under the inclined plate settler at other plants could not induce even distribution of flow. NaF used as a tracer was recovered more than 90% at investigated all basin. Morill index ($t_{90}/t_{10}$), Modal index ($t_p/T-HRT$) and short-circuiting index ($[M-HRT-t_p/M-HRT$) were determined from tracer test results performed at three WTPs. Those indices ranged 2.99~3.45, 0.44~0.72 and 0.23~0.47, respectively.

• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.544-555
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• 2015

This study aims to derivate of the relationship and rating curve for the flow discharge-total sediment using the measured field data from the main points of small-medium stream reaches in agrarian basin. The total sediment of measured data are obtained by bed load added to suspended load which analyzed using the particle size distribution curve of sieve test and the dry or the filtration method from the collected samples by samplers (DH-48, D-74 and BLH-84, BL-84) at the stream bed and the depth-averaged concentration, respectively. These field data had been collected from August 2012 to September 2014 at the seven measuring stations of the national-local channel reaches of the four study streams in the Nonsan river systems of agrarian basin. As a result, the relationships and the rating curve for the flow discharge-total sediment are derived as a function pattern of power law by analyzing on a distribution characteristic of the database set and it will be used as a useful tool to analyze erosion, deposition, and transportation in theoretical research as well as in practical application of the hydraulic sedimentation engineering.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.410-411
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• 2005

• 한국석유지질학회:학술대회논문집
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• spring
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• pp.1-111
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• 1998

• Proceedings of the Korean Sanitation Conference
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• 2004.11a
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• pp.45-53
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• 2004

• Journal of Korea Water Resources Association
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• v.38 no.8 s.157
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• pp.665-674
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• 2005

The aim of this study is to evaluate 3 types of sedimentation basins: dredging, shield skirt and auxiliary dam, constructed at inlets of two irrigation reservoir and to estimate the most beneficial type and fitted size, SAR(surface to area ratio), for pollutant removal efficiency(RE). For this, RE of major water quality items and change of physicochemical properties in sediments before and post construction of sedimentation basin(SB) were investigated. RE depended on SB types, water quality items and survey times with wide range from $-87\%$ to $92\%$. Long term overall removal efficiency by ROC(regression of concentration) method were $18\%$ in dredging, $29\%$ in shield skirt and $42\%$ in auxiliary dam type. There was a change of physicochemical properties in sediments at auxiliary dam type, while a slight change at dredging and shield skirt type. In comparison to RE, SAR and hydraulic retention time at 3 types of SB, auxiliary dam type was the most beneficial one. Thus, it is recommended that SB would be constructed in completely separated structure from water body of a reservoir with SAR ranged from 0.7 to $1.0\%.$

• Journal of Korean Society of Water and Wastewater
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• v.27 no.2
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• pp.215-222
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• 2013

The fluctuation of inlet flow to a water treatment plant makes a serious problem that it can change the outlet flowrate from each process abruptly. Since it takes very short time for the surface wave occurred from the fluctuation of inlet flow to reach the latter processes, it is impossible for operators to cope with that stably. In order to investigate the characteristics of hydraulic behavior for rectangular sedimentation basin in water treatment plant, CFD(Computational Fluid Dynamics) simulation were employed. From the results of both CFD simulations, it was confirmed that time taken for the follow-up processes by the fluctuation in intake well can be estimated by the propagation velocity of surface waves. Also, it takes very short time for the surface wave occurred from the fluctuation of inlet flow to reach the latter processes. In the case of inlet flowerate being increased sharply, local velocity within sedimentation basin appeared as wave pattern and increased due to convection current. Also, it could be observed that vortex made local velocity in the vicinity of bottom rise.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.419-423
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• 2006

Basic studies on natural gas hydrates in the East Sea were been carried out by the Korea Institute of Geoscience and Mineral Resources (KIGAM) from 2000 to 2004 involving 2D multichannel seismic lines and piston coring. 27 piston cores recovered from the deed-water Ulleung Basin of the East Sea were analyzed in this study. In piston cores cracks generally developed parallel to bedding suggest significant gas content. The core analyses showed high total organic carbon (TOC) content, sedimentation rate and heat flow of sediments. The cores recovered from the southern study area show also high residual hydrocarbon gas concentrations for the formation of natural gas hydrates. This study indicates that there is the potential for the generation of biogenic gas and the formation of natural gas hydrates in the near seafloor sediments of the study area.

• Journal of the Korean earth science society
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• v.23 no.3
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• pp.259-269
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• 2002

Based on sedimentary structures, degree of bioturbation, and internal erosional layers, the deep-sea core sediments in the East Sea (Ulleung and Yamato basins) and the Northwestern Pacific Ocean (Shikoku Basin) can be divided into two parts (upper and lower) with the boundary of around 10,000 years B.P. in age. The upper part of core KT94-10 from Shikoku Basin is characterized by low sedimentation rate, internal erosion layer, high degree of bioturbation and cross-lamination structures. It can be interpreted as the bottom-current deposits which show some different characteristics from turbidite or hemipelagic sediment. However, its lower part consists of highly bioturbated, massive mud, suggesting that it be not related to the influence of bottom current. On the other hand, the cores in Ulleung and Yamato basins do not show any evidence of bottom-current deposits: their upper parts consist of bioturbated mud, and lower parts are characterized by laminated mud with pyrite filaments, indicating anaerobic condition. Consequently, these sedimentological characteristics suggest that deep-sea circulation would be changed from slow-moving to fast-moving one at this bounding time commonly in the Northwestern Pacific Ocean and the East Sea. Also, even in the same time, the deep-sea circulation in the Northwestern Pacific area would be relatively faster than that in the East Sea.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.2
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• pp.43-52
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• 1994

In this paper, the unit processes in the typical water treatment plant, which need to be expanded because the water demand is over the existing water treatment capacity in the near future, were carefully examined to upgrade the water treatment plant. The models were installed in the fields as a distorted model based upon the hydraulic similitudes. The models having the constant discharge ratio in the unit processes between the model and the prototype were installed as two units to compare the treatment efficiencies. The capacity of the individual unit, which is a model of the prototype of $250,000m^3/day$ capacity, was $24m^3/day$. In the mixing and flocculation experiments, the mixing intensity of flocculators G was selected as the main experimental item. The optimal mixing intensities G, which are 65/sec for experimental discharge of $1m^3/hr$ and 85/sec for experimental discharge of $1.3m^3/hr$, are identified based upon the comparison the relative turbidity removal efficiencies. Also, the outlet weir loading was selected as the main experimental item in the sedimentation process. Through the continuous experiments with the main experimental items of the mixing intensity of flocculators G and the outlet loading of the weir in the sedimentation basin, about 20% upgrading compared to the existing water treatment capacity was obtained.