• Journal of Navigation and Port Research
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• v.43 no.5
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• pp.302-309
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• 2019

This study introduces the navigational environment database(DB) compiling water depth, sediment type and marine managed areas (MMAs) in coastal waters of South Korea. The water depth and sediment data were constructed by combining their sparse points of electronic navigation chart and survey data with high spatial resolution using the inverse distance weighting and natural neighbor interpolation method included in ArcGIS. The MMAs were integrated based on all shapefiles provided by several government agencies using ArcGIS because the areas should be used in an emergency case of ship. To test the validity of the constructed DB, we conducted a test application for grounding and anchoring zones using a ship accident case. The result revealed each area of possible grounding candidates and anchorages is calculated and displayed properly, excluding obstacle places.

• Journal of Environmental Impact Assessment
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• v.24 no.5
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• pp.444-455
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• 2015

In relation to the utilization and disposal of dredged sediment caused by coastal dredging project, we diagnosed the status of legal standard and system, and proposed the improvement plan. Dredging costal sediment distinguished the usage and the disposal by the Standard for the Beneficial Usage of Dredged Sediment. The site where disposal has been completed could be used as a site for developmental project. In case of the usage of dredged sediment for reclamation, we found that the adaptation of the Standard for Beneficial Usage of Dredged Sediment is appropriate for reclamation considering the characteristic of soil, the differences of variables, and the distinction of standard analysis methods. The current the Standard for Beneficial Usage of Dredged Sediment requires the improvement with the usage of dredging coastal sediment in the following. First, the Standard needs to include the standard of the discrimination for reclamation. Second, the current Standard is necessary to be divided by two levels, it needs to be mitigated considering human health risk. Third, it is necessary to consider both the marine environmental impact assessment and mitigation plan near coastal dredging area.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.584-593
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• 2021

The sediment makes up the sea floor and plays an important role as a habitats for living things in the sea. However, pollution of coastal sediment due to internal and external factors such as inflow of contaminants from land and self-pollution becoming more serious, the needs for management of sediment that play an important role in ecology, is increasing. In particular, the review and evaluation of the effects of sediment in marine development projects including reclamation and dredging, have significance in terms of proactive protection and management of surrounding ecosystems. This study proposed the improvement measures for marine sediment management standards on the sea area utilization consultation for the development of public water. For the purpose, The evaluation and management standards of domestic and overseas marine sediments were reviewed and compared. The sediment environment guidelines under the Marine Environment Management Act of Korea were reviewed. Accordingly, the cases of Canada and NOAA, which have various evaluation standards consist of comprehensive factors, were analyzed. For analysis of operational cases, the port and fishing port development projects for the last five years (2016-2020) that are considered to have the greatest impact on sediments among the sea area use consultations were also reviewed. Finally, this study suggested that the assessment factors for ecological hazards and potential human risks should be considered in the sediment environmental standards in the sea area utilization consultation system.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.655-661
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• 2014

In this study, stabilization treatment of heavy metals such as Ni, Cu, Pb, and Zn in contaminated marine sediment was achieved using bentonite. Stabilization experiment was accomplished by wet-curing with bentonite for 150 days. From the sequential extraction results of heavy metals, it was observed that the easily extractable fraction (exchangeable, carbonate, and oxides forms) of Ni, Cu, Pb, and Zn in a treated sediment decreased to 8.5%, 5.6%, 19.2%, and 28.2%, respectively, compared with untreated sediment. Moreover, the TCLP(Toxicity Characteristic Leaching Procedure) results evaluating efficiency of extraction reduction of heavy metals showed that extraction of heavy metals reduced drastically to 95.7%, 96.8%, 99.2%, 85.9% for Ni, Cu, Pb, and Zn by stabilization when compared to untreated sediment. From these results, we can confirm that bentonite as a capping material exhibits good stabilization of heavy metals in contaminated marine sediment.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.216-222
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• 2015

A previous velocity measurement system for marine sediment had several problems such as the errors occurred when picking first arrival time and the inconvenient measurement procedure. In order to resolve these problems, we developed a new acoustic properties measurement system by using PXI (PCI eXtentions for Instrumentation) module based on LabVIEW. To verify the new system, we measured the velocity and attenuation of sediment using the new system in a parallel with the previous system under the same experimental environment. The result of measurement showed 1~2% margin of error for the velocity as well as similar attenuation values. We concluded that the new system can efficiently measure the acoustic properties of marine sediment. It also has an advantage to construct the database of acoustic data and raw signal.

• Korean Journal of Environmental Biology
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• v.29 no.1
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• pp.23-30
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• 2011

In this study, the Comet assay (evaluation of DNA damage) used the fish hepatocellular carinoma cell, PLHC-1, was tried to the sediment extract obtained from freshwater to understand its applicability as a tool for monitoring sediment toxicity. In parallel, induced EROD (7-ethoxyresorufin- O-deethylase) activity and DNA damage (TEM values) in PLHC-1 cells were measured for establishing the tandem endpoints of the PLHC-1cell test to test the ecotoxicity of sediment. Among several study sites in a small river passed through downtown and industrial park area, one of them, site B, showed a higher level of EROD activity and DNA damage than other sites. It indicates that a tandem endpoints of PLHC-1 cells could be useful tools for assessing the toxicity of sediment. The sensitivity of Comet assay with PLHC-1 cells was a little higher than that with a blood cell of frog tadpoles to the solvent extract of sediment. According to the results, a PLHC-1 cell-Comet assay could be used as a useful tool for evaluating ecotoxicity of the freshwater sediment. In addition, more detailed studies are needed to the contaminated site.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.375-379
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• 2016

In this study, the structure and diversity of bacterial community were investigated in the surface and subsurface marine sediments using a NGS method (i.e. illumina sequencing technology). The bacterial community in the surface was distinct from that in the subsurface of marine sediment; with the exception of the phylum Proteobacteria, the relative abundance of Bacteroides phylum were higher in the surface than subsurface, whereas the sequences affiliated to the phyla Chloroflexi and Acidobacteria were relatively more copious in the subsurface than surface sediment. Moreover, interestingly, we observed that the phyla Nitrospinae and Nitrospirae contribute to nitrogen cycle in the marine sediment. This study may present the possibility for the presence of novel microorganisms as unexplored sources and provide basic information on the microbial community structure.

• Environmental Engineering Research
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• v.25 no.2
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• pp.230-237
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• 2020

Nitrogen flux release from organically enriched sediments into overlying water, which may have significantly influence on water quality and increasing continuous eutrophication. The purpose of this study is to evaluate the remediation efficiency of oyster shell powder and its treated product into organically enriched sediment in terms of nitrogen flux, organic matter, chlorophyll-a, pH and dissolved oxygen (DO). The TOSP was mainly composed of CaO2. The application of TOSP into the sediment has increased the pH, DO and significantly decreased the concentrations of NH₄⁺-N and T-N compared to other basins. On the other hand, nitrate was enriched with the addition of treated oyster powder, an oxygen releasing compound on both phases. Furthermore, chlorophyll-a was found to be increasing with time in the control basin meanwhile it dropped drastically with the addition of TOSP, which implied on the repression of algal growth owing to blockage of nitrogen source migrating from the sediment. This study has shown that the TOSP was effective to improve sediment-water quality, diminish eutrophication and control harmful algae blooms in a marine environment. Therefore, it is a good reference as an effective environmental remediation agent.

• Ocean Science Journal
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• v.40 no.4
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• pp.221-227
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• 2005

The architecture of macrofaunal burrows and the total area of the sediment-water interface created by biogenic structure were investigated in the Donggeomdo tidal flat on the west coast of Korea. Resin casting methods were applied to recover burrows of four dominant species, Macrophthalmus japonicus, Cleistostoma dilatatum, Perinereis aibuhitensis, and Periserrula leucophryna, and whole burrows within the casting area at three sites in different tidal levels. P. leucophryna excavated the largest burrow in terms of a surface area among them. In the case of whole burrow casting, the space occupied by the biogenic structure was extended into deeper and expanded more greatly at the higher tidal level. In the uppermost flat, the burrow wall surface area within sediment was more extensive than the sediment surface area. Increased oxygen supply through the extended interface could enhance the degradation rates of organic carbon and also change the pathways of degradation. Quantifying the relationship between the extended interface and mineralization rate and pathway requires more extensive study.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.2
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• pp.365-373
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• 2008

When the wind power system is planned to construct, it is important to understand the physical, chemical and mechanical properties of sediment. Especially, If it is the seabed unconsolidated sediment, we need to experiment on sediment through seabed unconsolidated sediment test and sediment survey. Because the sediment's properties are different as its formation, accumulation and load, unconsolidated sediment is difficult to be expected to its behavior. So we can estimate suitability for mechanical material and decrease the uncertainty through seabed unconsolidated sediment test. Seabed unconsolidated sediment test can be experimented in laboratory or in-situ as purpose, in-situ condition, economic problem. In this study, we sampled the seabed unconsolidated sediment at offshore around Korea Maritime University and measured properties of sediment through the laboratory test, showed the effect on physical properties of seabed unconsolidated sediment when the wind power system is planned to construction.