• Korean Journal of Ecology and Environment
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• v.39 no.4 s.118
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• pp.450-461
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• 2006

In this study, sorption kinetics of lead (Pb) and cadmium (Cd) onto coastal sediments were investigated at pH 5.5 using laboratory batch adsorbers. Four different models: one-site mass transfer model (OSMTM), pseudo-first-order kinetic model (PFOKM) ,pseudo-second-order kinetic model (PSOKM) and two compartment first-order kinetic model (TCFOKM) were used to analyze the sorption kinetics. As expected from the number of model parameters involved, the three-parameter TCFOKM was better than the two-parameter OSMTM, PFOKM and PSOKM in describing sorption kinetics of Pb and Cd onto sediments. Most sorption of Pb and Cd was rapidly completed within the first three hours, followed by slow sorption in the subsequent period of sorption. All models predicted that the sorbed amount at the apparent sorption ($q_{e,s}$) equilibria increased as the CEC and surface area of the sediments increased, regardless of initial spiking concentration ($C_0$) and heavy metal and the sediment type. The sorption rate constant ($k_s,\;hr^{-1}$) in OSMTM also increased as the CEC and BET surface area increased. The rate constant of pseudo-first-order sorption ($k_{p1,s},\;hr^{-1}$) in PFOKM were not correlated with sediment characteristics. The results of PSOKM analysis showed that the rate constant of pseudo-second-order sorption ($k_{p2,s},\;g\;mmol^{-1}\;hr^{-1}$) and the initial sorption rate ($v_{o,s},\;mg\;g^{-1}\;hr^{-1}$) were not correlated with sediment characteristics. The fast sorption fraction ($f_{1,s}$) in TCFOKM increased as CEC and BET surface increased regardless of initial aqueous phase concentrations. The sorption rate constant of fast fraction ($k_{1,s}=10^{0.1}-10^{1.0}\;hr^{-1}$) was much greater than that of slow sorption fraction ($k_{2,s}=10^{-2}-10^{-4}\;hr^{-1}$) respectively.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.8
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• pp.1275-1280
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• 2009

Tidal currents were observed at 1 station of artificial reefs group during 15days. Maximum current was 82.4cm/s, and mean current showed 12.8~28.0cm/s, respectively. Flood currents magnitude were bigger than ebb ones due to wake region. To grasp sediment distributions, sediments were sampled at 4-direction(E, W, S, N) around each station. According to the results of sample analysis, sediments showed different distribution by main current direction. It showed that sediments distribution at front and back of artificial reefs were differently occurred by change of main current direction. It suggest that artificial reefs need to install after confirming tidal currents direction and sediments type.

• Journal of Environmental Impact Assessment
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• v.18 no.4
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• pp.229-234
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• 2009

A lot of research on the application of GIS has been conducted in the field of water quality management. The function of a geometric data acquisition for reservoir and river models, however, is not enough to satisfy multiuser' convenience. CE-QUAL-W2 is a two-dimensional(2D) longitudinal/vertical hydrodynamic and water quality model for surface water bodies, modeling eutrophication processes such as temperature-nutrient-algae and sediment relationships. The purpose of this study is to analyzing which bathymetry information affects hydraulic results. There are consisted of three scenarios under consideration. The first scenario takes into account only tribatary type data such as Heoin and Okchen river. The second scenario, Heoin river constructs to tributary and Okchen river constructs by branch. Last scenario constructs Heoin and Okchen river by branch. The RMSE error results for the first, second and third scenarios are 0.61, 0.36 and 0.28 respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.1
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• pp.68-72
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• 2009

To gain a greater understanding of the potential for future harmful algal bloom (HAB) outbreaks and to trace the dispersal paths of dinoflagellates, sediment samples were collected from 13 stations in the southeastern Yellow Sea. 23 different types of dinoflagellate resting cysts were identified from the samples. Protoceratium reticulatum (1-391 cells/g dry weight), Gonyaulax scrippsae (0-254 cells/g dry weight), G. spinifera (0-301 cells/g dry weight) and Alexandrium spp. (ellipsoidal type) (0-76 cells/g dry weight) were the dominant species at all surveyed stations. The overall distribution pattern demonstrated that the resting cyst densities were highest in the offshore area and decreased gradually toward the Korean coast. On the other hand, the composition rate of resting cysts of the heterotrophic dinoflagellate species to the total dinoflagellates was higher in the Korean coast region than in the offshore area. We supposed that this distribution pattern of dinoflagellate resting cysts appeared to be influenced by the hydrographic features and environmental conditions of the Yellow Sea.

• Journal of Environmental Impact Assessment
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• v.15 no.5
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• pp.289-297
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• 2006

The study investigates the problems of silt protector used for mitigation measure of suspended sediments (SS) during coastal construction and provides their improvements based on the field investigation and analysis of the environmental impact assessment reports for the coastal development projects of Korea. The field investigation along west, east and south coasts of Korea reveals a variety of problems in the installation and management of silt protector solely used for the SS mitigation in Korea. Major problems include installation itself, low cost and quality of silt protector, and maintenance. These problems superimpose the effectiveness of silt protector in mitigating coastal environment impact. The present study provides the specific guideline on the project type needed for the installation of silt protector, installation standard and planning, maintenance and management. The study also suggests new mitigation options such as environmental window to limit the construction period and environmental dredger to compensate for the deficits of silt protector.

• ALGAE
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• v.26 no.1
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• pp.41-50
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• 2011

Yellow Sea surface sediment samples collected on October 15-31, 2003 were analyzed using the palynological process to investigate the spatial distribution of dinoflagellate resting cysts. The sampling areas comprised four latitudinal transects, the northernmost of which was located off the Shandong Peninsula, China and the southernmost off Jeju Island, Korea. Each transect line was composed of six to nine stations, spanning the distance between the Chinese and Korean coasts. Twenty-five different types of dinoflagellate cysts were identified. Gonyaulax scrippsae, Alexandrium spp. (ellipsoidal type), and G. spinifera were the most dominant at all stations surveyed. Dinoflagellate cysts belonging to the Gonyaulacales comprised over 50% of all cysts collected. The latitudinal distribution trend showed that cyst concentrations along the two middle transects were much higher than those along the two northern and southern transects. Cyst concentrations in the offshore central areas reached their highest values within each transect and gradually decreased toward the Chinese and Korean coasts. Overall, cyst concentrations were markedly elevated in the offshore central Yellow Sea areas and gradually decreased outward in all four directions. This concentric cyst distribution pattern was consistent with the hydrographic features of the Yellow Sea, such as circular current systems, sedimentary properties, and water depth.

• Economic and Environmental Geology
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• v.30 no.5
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• pp.407-416
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• 1997

Soil, tailings, stream sediment and surface water samples collected in the vicinity of the Geumwang Au-Ag mine were analyzed in order to investigate the pollution level of heavy metals and to determine the dispersion patterns. Although the maximum concentrations of soils collected at the flotation plant and tailings dam were 9,270 ppm As, 17 ppm Cd, 1,480 ppm Cu, 10,080 ppm Pb and 18,400 ppm Zn, dispersion of heavy metals were limited in the vicinity of the flotation plant and tailings dam. This may be due to high pH values (> 8.0) of the soils by flotation solution for mineral processing. The pH values of water samples near the flotation plant and tailings dam were over 8.0 and Cd, Cu and Zn concentrations were not detected. The waters in the vicinity of Geumwang mine generally belong to a $Ca^{2+}-SO_{4}{^{2-}}$ $(HCO_3{^-})$ type.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.41-45
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• 2007

Polaromonas naphthalenivorans CJ2, responsible for naphthalene degradation at a coal tar contaminated site, was isolated on MSB agar media supplied with naphthalene vapor as the sole carbon source at $10^{\circ}C$. The strain is not isolated under the same isolation condition using the same soil sediment at $20^{\circ}C$ although its optimum temperature is about $20^{\circ}C$. In this work we explored the reason why strain CJ2 could not have been isolated on MSB agar with naphthalene vapor at $20^{\circ}C$. Dispersed CJ2 cells in PBS buffer formed colonies on MSB agar with naphthalene vapor at $10^{\circ}C$ with low naphthalene vapor pressure, but not at $20^{\circ}C$ with high naphthalene vapor pressure. However, streaked cells without resuspension grew on MSB agar with naphthalene vapor at $10^{\circ}C,\;20^{\circ}C$, and even $25^{\circ}C$. Investigation of scanning electron microscopy showed that CJ2 cells formed extracellular polysaccharide (EPS) capsules, which were released easily from CJ2 cells by just dispersion. Therefore, it is concluded that strain CJ2 is able to overcome the naphthalene toxicity by forming a capsule-type barrier around the cells although it is susceptible to naphthalene toxicity at high temperature.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.97-105
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• 2009

Analysis was done on the particle size distribution of sediments flown into Saemangeum from the Mankyung and Dongjin River. The organic pollutants and heavy metal existing in the sediments were analyzed, which was further used to study the properties of pollution in the sediments according to the particle size distribution. Conclusions shown below were made from these analyses. The particle size distribution showed a big difference between the upriver areas of Mankyung and Dongjin River. Particles under $75{\mu}m$ showed to be around 85% at Dongjin River, while it showed to be around 70% at Mankyung River. This kind of distribution in particle size concluded in greatly affecting the contamination density of the sediments. From the analysis done on the soil type of sediments, deposition in Mankyung River categorized into Silty loam and Sandy loam, where Silty loam covered most of area and deposition in Dongjin River categorized into Sand, Loamy sand, Silty loam, Sandy loam. Considering the weight ratio, the density of contamination of the sediments by particle size at Dongjin and Mankyung River has been analyzed to show that organic pollutants and heavy metals occupy more than 70% of the whole contamination in the range under the particle size of $75{\mu}m$.

• The Korean Journal of Malacology
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• v.21 no.1
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• pp.65-70
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• 2005

The purpose of this study is to determine the appropriate substrate for larval settlement and spat growth in the purple clam, Saxidomus purpuratus in laboratory culture. Larvae were reared with 3 different types of sediments (mud, sand, and mixed) for 46 days in settlement experiment, and settled spats were further grown in 3 types of sediments for 36 weeks in growth experiment. The density of settled spats in muddy sediments was more than 2 times higher than those in mixed or sandy sediments. But, the average size of settled spats in muddy sediments was smaller than those in mixed or sandy sediments. After 36 weeks of growth period, growth rate decreased as shell length increased. When shell length was less than 2 mm, growth rate in mixed sediments was significantly higher than that in sandy sediments. When shell length was more than 2 mm, there was no significant difference in growth rate among different substrates. Sediment type affected growth rate only when the spats were relatively small (less than 2 mm). Muddy sediments seems better for larval settlement, while mixed sediments is best for spat growth. We suggest the laboratory procedure for enhancing seedling production of S. purpuratus.