• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.309-310
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• 2001

국내에서 바지락 양식은 경기도 연안의 간석지에서 1912년에 시작되었다고 보고되어 있으며, 1980년부터 본격적인 양식이 시작되어 1990년에 최고 생산량을 기록하였다. 그러나 최근에는 매립에 의한 서식장 감소, 양식장의 밀식에 따른 자가 오염 및 환경변화 등에 의한 바지락 폐사에 따라 생산량 감소가 야기되어 지속적인 바지락 양식장 유지관리의 중요성이 대두되고 있다. 곰소만 조간대 및 주변 해역에서의 기존연구는 지질학적 특성뿐 만 아니라, 생물학적 특성, 퇴적물의 물리적 특성, 그리고 해역의 수리역학적 특성을 포함한 포괄적인 연구에 관해서는 미흡한 실정이다. (중략)

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.3
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• pp.129-137
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• 2005

In this study, we developed a model to simulate the interaction between sediment and the overlying water. The model deals with water-sediment interaction in terms of the sedimentation of organic detritus from the pelagic zone into the benthic zone and the release of nutrients occurring in the reverse direction. The model was tested and verified by comparing the predicted release rates of phosphorus from the sediment in Osaka Bay with actual observed values. The results accurately reproduced the seasonal change in release rates. The results well represented seasonal change of the release rates. A long-term prediction of water and sediment quality was performed for the period from 1950 to 1999. Nutrient loads from land and the boundary conditions of 3-D baroclinic flows were season-adjusted. The model accurately reproduced the changing trends in phosphorus, nitrogen, and COD concentrations in Osaka Bay over a long period of time.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.640-645
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• 2014

This study aimed to determine the swimming suitability of sea and to suggest methods to address the problems on sea water color and green plants growing on sediment in the artificial created swimming in the beach of southwestern Korea. Sea water samples were collected from January to December of 2010 and analysis for SS, COD, $NH_4{^+}-N$, TP, MPN, sediment IL, ORP and plants on sediment. The results showed that the sea water under the swimming suitability "level of management" based on the relating high levels of SS and TP, but still suitable for swimming on the basis of MPN. Improving exchange seawater flow, dredging, coating and chemical treatment of polluted sediments in addition to removal of point sources and restriction of non point sources in the study area could improve the sea water quality and swimming suitability of the sea.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.1
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• pp.41-49
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• 1999

The horizontal two-dimensional model which can predict the long-term water quality(WQ) change is setup for the environmental management. For the model calibration and verification, we measured the pollutants load at 22 streams and the WQ at 16 stations monthly and/or seasonally in Chinhae . Masan Bay. The pollutants release rate from the sediment was also measured to consider the regionally different sediment pollution level. From the model application results, it is shown that the WQ concentrations in most of the regions adjacent to land and river inflow are considerably high, but rapidly decrease along the seaward direction. In Masan Bay, the particulate inflow-pollutants were substantially deposited and gradually contaminated the bottom sediment on account of the excessive pollutants load and flow stagnancy. Eutrophication in the effluent discharge region was also being slowly progressed by the inefficiently treated wastewater containing amount of Nand P constituents.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.177-178
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• 2015

Sediments play a major role in determining pollution pattern in aquatic systems and reflecting the pollutant deposition. In the present study analysis the depth effect of organic pollutants and heavy metals using slow release biostimulant ball (BSB) in coastal sediment. BSB size fixed at 3cm, depth varied from 0cm to 10cm depth and 1 and 3 month interval period was carried out for the study. The organic pollutants of chemical oxygen demand, total solids and volatile solids were significantly changed at the surface sediment (0cm)in 1 month and 3 month interval time using BSB. In contrast, sediment depth increase upto 10cm the reduction percentage decrease like to control. Vertical distribution of heavy metals are not consistent from the surface layer toward the bottom layers. Heavy metals fractions were significantly changes, the exchangeable fraction was reduced and other organic and residual fractions were stabilized percentage are increased. This finding concluded BSB is effective for reduce organic pollutants, heavy metals stabilization from the contaminated sediment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.681-688
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• 2020

Approximately 6,000 chemicals are transported through the sea, including hazardous and noxious substances (HNS), which cause marine pollution and are harmful to marine life. The HNS discharged into the sea during the maritime transportation process undergoes physical and chemical changes on the sea surface and in seawater, and some types of HNS sink and are deposited on the seabed. The HNS deposited on the seabed adversely affects the benthic ecosystem, and hence, it is desirable to detect, treat, and recover the HNS on the seabed. Therefore, this study was conducted to analyze the performance requirements that should be considered as the top priority when developing a mechanical system for recovering the HNS deposited on the seabed. Various types of existing dredging devices used for collecting and recovering pollutants from river beds and seabeds were investigated, and 10 performance indices for the mechanical devices were selected. The new performance requirements for the development of the seabed-deposited HNS recovery system were proposed using performance indices. By considering the depth of water in domestic seaports, some of the performance requirements of the mechanical system for recovering deposited HNS from the seabed were obtained as follows: production rate (50-300 ㎥/hr), maximum operation depth (50 m), sediment type (most forms), percentage of solids (10 % or higher), horizontal operating accuracy (±10 cm), limiting currents (3-5 knots). These performance requirements are expected to be useful in the conceptual and basic design of mechanical systems for recovering seabed-deposited HNS.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.1
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• pp.39-50
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• 2003

This study aims to figure out water quality impacts due to sudden disturbances of sediments during dike construction in land reclamation for the northern part of the Siwhaho Lake where heavily deteriorated settlements from upstream loadings are outstanding. We exploit a 3-D water quality model CE-QUAL-ICM combined with a hydrodynamic model TIDE3D. Simulations are done accounting water-sediment interaction in a 4-$\sigma$ layers. Long-term simulation for 1-year shows that bottom layers around the disturbance location are only affected and marks very high concentration. Complete vertical mixing appears at least 5km apart to downward due to complex effects of geometry, bathymetry and river inflows. It should be addressed that existing condition of the Siwhaho Lake stands for high concentration of COD and TP in winter and spring due to relatively high incoming loadings, however the effect of sediment disturbances yields reverse phenomena, i.e., impacts of dike construction arise greatly in summer and fall. Refined grid system consisting of 150m${\times}$150m rectangular grid, which is doubled system compared to previous study (Suh et al.,2002), gives affordable results by reducing flux differences through a cell especially in front of gate.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.46-47
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• 2013

We prepared biostimulant balls using sea sediment mixed with biostimulants viz acetate, nitrate and sulfate. The Biostimulant balls were coated with Cellulose Acetate (CA) and Polysulfone (PS) to control the release of the biostimulants. SEM images showed that CA coating was porous and irregular in the inside and very uniform and tight like beehive while PS coating was the same in the inside and outside and not porous. Biostimulants release was found to be high in sea water compared to distilled water. The release of nitrate was higher compared to sulfate. In turbulent environment the release of bionutrients was 50% higher than static environment.

• Journal of Environmental Impact Assessment
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• v.30 no.2
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• pp.61-74
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• 2021

In this study, we used marine environment assessment indices to evaluate impacts of various development projects on the marine environment. TheWaterQuality Index (WQI) was applied in the field of marine water quality and the Cleanup Index of Harmful Chemicals (CIHC), the Cleanup Index of Eutrophication (CIET), the Enrichment Factor(EF) were used in the field of marine sediment. In the field of marine benthic organisms, the Benthic Health Index (BHI) and the Benthic Pollution Index (BPI) were utilized. Each assessment index was calculated using the data observed in the development project, and its characteristics and usefulness were evaluated. The assessment method and criteria were clearly defined for WQI, CIHC, and BHI. Furthermore, through these indices, an integrated environment impact analysis was possible. Apart from the indices presented in this study, there are various indices that can be used for evaluating the marine environment. Therefore, it is important to utilize appropriate indices according to the characteristics of each project.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.133-147
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• 2004

Environmental quality(water and sediment) was analyzed in the tidal flat of Saemangum of Jeonbuk Province, the west coast of Korea, using the 101 sediment samples and 69 water samples collected in September 4~13, 2001. Major water quality parameters with the means of 69 surface water samples are as follows; $25.51{\pm}0.68^{\circ}C$ for water temperature, $29.88{\pm}5.01$ for salinity, $1.40{\pm}0.78mg/L$ for COD, $0.352{\pm}0.417mg/L$ for DIN, and $0.027{\pm}0.023mg/L$ for phosphate, respectively. Higher values were found at the subestuary of Dongjin and Mangyung River, and lower values at the Saemangum embayment and Gomso Bay. There was a significant negative correlation between salinity and the other water quality parameters(p<0.0001) such as COD, nutrients, SS and N/P. This correlation suggested that the major pollution sources be from terrestrial inputs through tributaries in this area. Principal component analysis clearly revealed a spatial variation of water quality; stations with higher values of nutrients and COD located subestuary of tributaries. 14 sediment quality parameters including 8 trace metals were measured using the 101 surface sediment samples. Average values for the parameters are as follows; Al $2.28{\pm}0.92%$, Cd $0.61{\pm}0.27ppm$, Cu $8.95{\pm}4.06ppm$, Fe $1.19{\pm}0.37%$, Mn $182.31{\pm}77.45ppm$, Ni $10.83{\pm}4.97ppm$, Pb $15.20{\pm}4.35ppm$, Zn $41.34{\pm}34.62ppm$, COD $2.68{\pm}1.85mg/g\;dry$, AVS $0.04{\pm}0.08mg/g\;dry$, IL $1.29{\pm}1.08%$, water content $24.11{\pm}4.49%$, TN $0.02{\pm}0.02%$, TC $0.22{\pm}0.30%$. Spatial variations of sediment quality were not clear as water quality. Some higher values were found at the subestuary of Gum River and lower values at the other area. There was a significant positive correlation between the heavy metal concentrations and organic materials within the sediment(p<0.05). Enrichment factors showed the ranges of 1~2 for most of the metals in the sediment except zinc(1~6), indicating no serious exogenous input of heavy metals in the study area. Also, the heavy metal concentrations in the sediment were within the ranges found at the natural marine environments.