• Journal of Korean Society of Environmental Engineers
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• v.34 no.11
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• pp.751-756
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• 2012

In this study, a heavy-metal stabilization treatment using stabilizing agents derived from waste resources was utilized on Incheon North Port range sediment contaminated with Pb, Zn, and Cu. Both calcined red mud (5%, 10%, and 15% w/w) and oyster shell (5%, 10%, and 15% w/w) were applied for a wet-curing duration of 15 days. From the sequential extraction results, the oxide and organic fraction of heavy metals (Pb, Zn, and Cu) were observed strongly in the contaminated sediment. However, the fraction of heavy metal in the stabilized sediment was higher than the organic and residual fraction, in comparison to the contaminated sediment. Moreover, the leaching of heavy metals was reduced in the stabilized sediment, compared with the contaminated sediment. From these results, red mud and oyster shell were shown to be potential stabilizers of heavy metals in contaminated sediment.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.58-58
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• 2010

The sediment geochemistry, including REE of surface and core samples in the western part off Jeju Island have been carried out in order to understand the provenance and hydrolic sorting. The sediment in the study area were primarily composed of coarse silt with a mean grain size of $2.8{\sim}82.8{\mu}m$. The ratios of TOC over total nitrogen (TN) showed that the study area sediments contained more organic matters of marine origin than those of terrigenous origin. The total A1203, Fe203, K20, MgO, and MnO contents and REE concentration of the fine sediments are higher than those of the coarse sediments. The higher Zr/Th and Zr/Yb ratios in coarse sediments relative to fine-grained detritus indicates sedimentary sorting. Grain size influence the REE concentrations of the study area sediment significantly. The < $63{\mu}m$ fraction of the sediment has higher REE concentration and different REE patterns when compared with those in bulk samples, due to the presence of REE-enrich heavy minerals. The REE distribution patterns of the western part of Jeju Island sediments are relatively enriched in most LREEs than the Yellow River sediment and depleted in the Changjiang River, but the LaN/YbN ratios are similar to the Changjiang sediment. The Eu/Eu* ratios ranged from 0.594~0.665(0.631) is much similar to the Yellow River sediment, possibly mixture of the sediments from these two rivers.

• Journal of Environmental Impact Assessment
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• v.18 no.3
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• pp.131-141
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• 2009

We studied improvement in marine environmental impact assessment and related management systems of coastal sediments that are dredged inshore but disposed offshore. After reviewing and diagnosing the existing assessment procedures and problems, we recommend to design the core assessment items and improve the reliability of assessment byenhancing the quality assurance/quality control (QA/QC) and verification processes. We proposed eco-friendly disposal plan for dredging sediment such as reuse system in land development was explored. A marine environmental database system was established to support the assessment processes. Guidelines for marine research and modelling were proposed for improving assessment of dredging and disposal of coastal sediment. Also, applying of screening and scoping for marine environmental assessment was reviewed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.699-709
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• 2017

We measured the grain size, total organic carbon (TOC), total nitrogen (TN), and heavy metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn) in order to understand the spatial distribution and pollution level of organic matter and metals in surface sediment around Goseong Bay, a shellfish farming area, Korea. The surface sediments were composed of finer sediments such as mud and clay. The concentration of TOC, TN, and heavy metals were much higher in the innermost bay than in the mouth and outside of bay. The spatial distribution of organic matter and heavy metals and C/N ratio (5-10) in sediment showed that the organic matter and heavy metals in sediment of the study region were significantly influenced by oceanic origin organic matter and anthropogenic sources, respectively. Based on the results of four assessment techniques (sediment quality guideline, geoaccumulation index, pollution load index, ecological risk index), the sediments around the Goseong Bay were a little polluted for heavy metals and the high metal concentrations in the northern region of bay could adverse impact on benthic organisms in sediment. Thus, the systematic management plan for the improvement of water and sediment environment and the concentrated monitoring of pollutants for sustainable aquaculture and seafood safety around Goseong Bay are necessary in the future.

• The Journal of the Acoustical Society of Korea
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• v.25 no.2E
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• pp.60-68
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• 2006

High-frequency bistatic scattering measurements from a corrugated surface were made in an acoustic water tank. First the azimuthal scattering pattern was measured from an artificially corrugated surface which has varying impedance. The corrugated surface was installed both transverse to the direction of incident wave and longitudinal to the direction of incident wave. The angle between the corrugated surface and the direction of the incident wave was about $45^{\circ}$. Second, the scattering strengths were measured from the flat sediment and the corrugated sediment. A critical angle of about $37^{\circ}$ was calculated in the acoustic water tank. The measurements were made at three fixed grazing angles: $33^{\circ}$ (lower than critical angle), $37^{\circ}$ (critical angle), and $41^{\circ}$ (higher than critical angle). The scattering angle and the grazing angle are equal in each measurement. Frequencies were from 50 kHz to 100 kHz with an increment of 1 kHz. The corrugated sediment was made transverse to the direction of the incident wave. The first measurement indicates that the scattering patterns depend on the relations between the corrugated surface and the direction of the incident wave. In the second measurement, the data measured from the flat sediment were compared to the APL-UW model and to the NRL model. The NRL model's output shows more favorable comparisons than the APL-UW model. In case of the corrugated sediment, the model and the measured data are different because the models used an isotropic wave spectrum of sediment roughness in the scattering calculations. The isotropic wave spectrum consists of $w_2$ and ${\gamma}_2$. These constants derived from sediment names or bulk size. The model which used the constants didn't consider the effect of a corrugated surface. In order to consider a corrugated surface, the constants were varied in the APL-UW model.

• Journal of the Korean Geotechnical Society
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• v.19 no.3
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• pp.33-38
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• 2003

Marine sediment capping is a technique where clean sand is placed over contaminated sediment to reduce the migration of contaminants to the environment. The design of in-situ caps placed over marine sediment must take into consideration the self-weight consolidation of the cap and the consolidation of the sediment as a result of adding the cap layer. Centrifuge tests were adopted to simulate the effects of consolidation settlement of capped marine sediment caused by the placement of a clean sand layer. The modeling of models technique was utilized to verify the correct modeling procedures used in this study. Two centrifuge tests were conducted with the same boundary conditions at different gravitational accelerations of 100 g and 50 g. There was good agreement between these tests. It can be concluded that the centrifuge experiment is able to model consolidation settlement of capped marine sediment.

• Journal of Environmental Science International
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• v.28 no.10
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• pp.851-861
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• 2019

In this study, we performed a sediment elution experiment to evaluate water quality in terms of phosphorus, as influenced by the dissolved oxygen consumed by sediments. Three separate model column treatments, namely, raw, calcined, and sonicated oyster shell powders, were used in this experiment. Essential phosphorus fractions were examined to verify their roles in nutrient release from sediment based on correlation analyses. When treated with calcined or sonicated oyster shell powder, the sediment-water interface became "less anaerobic," thereby producing conditions conducive to partial oxidation and activities of aerobic bacteria. Sediment Oxygen Demand (SOD) was found to be closely correlated with the growth of algae, which confirmed an intermittent input of organic biomass at the sediment surface. SOD was positively correlated with exchangeable and loosely adsorbed phosphorus and organic phosphorus, owing to the accumulation of unbound algal biomass-derived phosphates in sediment, whereas it was negatively correlated with ferric iron-bound phosphorus or calcium fluorapatite-bound phosphorus, which were present in the form of "insoluble" complexes, thereby facilitating the free migration of sulfate-reducing bacteria or limiting the release from complexes, depending on applied local conditions. PCR-denaturing gradient gel electrophoresis revealed that iron-reducing bacteria were the dominant species in control and non-calcined oyster shell columns, whereas certain sulfur-oxidizing bacteria were identified in the column treated with calcined oyster powder.

• Ocean and Polar Research
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• v.26 no.2
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• pp.265-272
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• 2004

This study was conducted to investigate the community structure and distributional pattern of meiobenthos in the deep-sea bottom of the Clarion-Clipperton Fracture Zone of northeastern Pacific during July 2001. Examination of sediment samples collected on the eight survey station showed that there were 10 different types of meiobenthos. The most abundant meiobenthic animals were nematodes in all stations. Sarcomastigophorans, benthic harpacticoids were next abundant meiobenthos. Vertical distribution of meiobenthic animals showed the highest individual numbers in the surface sediment layers of 0-1 cm depth and showed more steep decreasing trend as sediment gets deeper on the stations of high latitude located in $16-17^{\circ}N$. Horizontal distribution of meiobenthic animal in the study area within CCFZ showed high densities of meiobenthos at the stations had few manganese nodules on their sediment surface in the site of low latitude. For size distribution analyses showed that animals which fit into the sieve mesh size of 0.063 mm were abundant.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.1
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• pp.47-58
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• 1999

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in coastal marine environment. PAHs enter estuarine and nearshore marine environment via several routes such as combustion of fossil fuels, domestic and industrial effluents and oil spills. In August of 1997, sediment and mussels (Mytilus edulis) were collected at 6 sites near Kori nuclear power plant in order to analyze the PAH content by HPLC with uv/vis detection. The concentrations of 15 PAH in sediment ranged from < 1 to 5,900 ppb ( mean 173.5$\pm$99.7 ppb), and in mussels, from < 0.5 to 4,125 ppb (mean 105$\pm$60.5 ppb). Compared with other studies world over, the concentrations of carcinogenic PAHs were relatively low in both sediment and mussels from the intertidal zone of Kori. This study presents preliminary data for the PAH levels in sediment and mussels from the intertidal zone of Kori, and the data will hopefully be utilized for the assessment of oil pollution in the Southeast East Sea, Korea (especially for the PAHs).

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.31-38
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• 2015

This study aims to assess the effectiveness of limestone, zeolite, and crushed concrete as capping material to block the release of heavy metals (As, Cu, Cr, Ni, and Pb) and reduce the sediment oxygen demand. The efficiency of limestone, zeolite, and crushed concrete was evaluated in a reactor in which a 1-cm thick layer of capping materials was placed on the sediments collected from Inchon north harbor. Dissolved oxygen concentration and heavy metal concentration in seawater above the uncapped sediments and capping material were monitored for 17 days. The sediment oxygen demand was in the following increasing order: crushed concrete ($288.37mg/m^2{\cdot}d$) < zeolite ($428.96mg/m^2{\cdot}d$) < limestone ($904.53mg/m^2{\cdot}d$) < uncapped ($981.34mg/m^2{\cdot}d$). The capping materials could reduce the sediment oxygen demand by blocking the release of biochemical matters consuming dissolved oxygen in seawater. It was also shown that zeolite and crushed concrete could effectively block the release of Cu, Ni, and Pb but those were not effective for the interruption of As and Cr release from marine contaminated sediments.