• Journal of the korean society of oceanography
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• v.33 no.4
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• pp.178-184
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• 1998

To elucidate contamination levels and distribution of methyl mercury (Me-Hg) in Korean coastal areas, 126 sediment samples were collected from Kyeonggi Bay, Namyang Bay, Chinhae Bay, and Lake Shihwa during 1995-1996, and the Me-Hg concentrations were determined by cold vapor atomic fluorescence spectrometry (CVAFS). Contamination levels of Me-Hg in sediments from Kyeonggi Bay, Namyang Bay, Chinhae Bay, and Lake Shihwa were 274 ${\pm}$ 990, 108 ${\pm}$ 24, 294 ${\pm}$ 342, and 1080 ${\pm}$ 760 pg/g, respectively. Concentrations of Me-Hg in sediments were significantly correlated with total organic carbon and sulfur contents, but were independent of mud contents and mean grain size. The highest concentration of Me-Hg (7100 pg/g) was observed at Incheon North Harbor (Site Kl9) in Kyeonggi Bay. This Me-Hg concentration was one or two orders of magnitude higher than those in other Kyeonggi Bay sediments were. The average concentration of Me-Hg in sediments from Lake Shihwa was higher than in those from other study areas. The three peaks of Me-Hg concentrations were observed on three sites (55, 56,and 510) in Lake Shihwa and gradually decreased in distance-dependent manner around these sites. High concentrations of Me-Hg at surface and 10-cm sediment depth in Chinhae Bay maybe due to higher rates of methylation process by active sulfate-reducing bacteria or higher concentrations of total mercury available to sulfate-reducing bacteria.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.4
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• pp.521-526
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• 2012

This study was conducted in order to analyze the ingredients and antioxidant activity of Suaeda japonica (turkey), which is abundantly present in Korea where mud flats are well formed due to the characteristics of halophytes. In the analysis of general composition, contents of carbohydrates, proteins, ash, and moisture were 10.7%, 8.3%, 7.6%, and 72.5% respectively. Among minerals, sodium was measured as 5.4%, which means that most ash was made of sodium. Heavy metal contents of lead, cadmium, arsenic, and mercury were 0.86 ppm, 0.04 ppm, 0.39 ppm, and 0.01 ppm, meaning Suaeda japonica satisfied standard food values. The 70% ethanol extract from Suaeda japonica was evaluated for its free radical scavenging activity and compared with a commercial antioxidant, BHA (butylated hydroxyanisole). As a result, the scavenging activities of hydroxyl radical, hydrogen peroxide, and xanthine oxidase of the extracts were equivalent to 30~50% of that of BHA.

• Economic and Environmental Geology
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• v.49 no.5
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• pp.335-347
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• 2016

The mineralogical and geochemical characteristics of diverse carbonate rocks can be investigated by using VNIRSWIR(visible near infrared-short wavelength infrared) spectroscopic analysis as a rapid, nondestructive, and inexpensive tool. Comparing whole rock analysis to VNIR-SWIR spectroscopic analysis, the analytical method was investigated to estimate CaO contents, mud impurity, and whiteness of carbonate rocks involved in high-grade limestones in the field. We classify typical carbonate rocks in the upper Pungchon Formation in high-grade limestone mine area such as the Gangweon, Chungmu and Baegun mine in the Jeongseon area. The results show that powdered specimen has much higher reflectance than cutted specimen between the same sample. Whiteness is highly correlated with reflectance(0.99) for powdered specimen. The absorption of mineral mixtures shifts in position as a result of the mass ratio of calcite and dolomite in the Chungmu mine by changing to 75:25, 50:50, and 25:75. The absorption peak position in carbonate mixtures is highly correlated with CaO contents(0.98~0.99). Based on color system, the carbonate rocks are grouped into (milky) white, light grey, light brown, grey, and dark grey. The absorption peak position shifts from 2340 nm to 2320 nm as CaO contents decrease from 55.86 wt.% to 29.71 wt.%. We confirmed that absorption peak position shifts depending on the amount of Ca, which is bonded to $CO{_3}^{-2}$, Mg, and Fe contents replacing Ca. This result suggests that CaO contents in carbonate rocks can be considered to quantitative analysis in the field by spectroscopic analysis.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.3
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• pp.251-261
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• 2006

The purpose of this study is to quantitatively estimate the settling property for fine-cohesive sediments in Keum Estuary and to evaluate the spatial variation by analyzing and comparing the local and seasonal variation of the settling properties in Keum Estuary with that of the settling properties in the other sites. After the spatial variation of physico-chemical properties such grain size distribution, the percentage of organic contents, mineralogical composition etc is investigated through experiments and analyses, interrelation between the physico-chemical properties and settling velocities and effect that the physico-chemical properties have on the quantitative variation of settling velocities were also analyzed in this study. Experimental results of settling tests shows that settling velocities of Keum Estuary mud vary in the range of two orders of magnitude (from 0.01 to 1mm/sec) over the corresponding concentration range of 0.1 to 80 g/L, and a feature of settling velocity profile is quite different in quantity as compared to those of previous studies with mud of other regions: Saemankuem, Tampa Bay, Sevem Estuary and lake Okeechobee. However, their local and seasonal variabilities within Keum Estuary appear to be insignificant.

• Journal of the Korean earth science society
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• v.18 no.6
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• pp.540-552
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• 1997

For the scientific and systematic study of sediment deposits along Yeongsan river, total 13 core samples were taken from Yeongsan river. The thickness of sediment deposits is 22.0m at YS 1, 20.0m YS 2, 18.5m YS 3, 12.0m YS 4, 3.0m YS 5, 5.5m YS 7, 3.0m YS 8, 5.9m YS 9, 5.0m YS 10 on main stream of Yeongsan river. The thickness of deposit is increasing from upstream to downstream. The composition of sediments dominates sandy gravel on the upstream and the lower part on the downstream, and mud deposits of $11m{\sim}16m$ thick on the upper part of on the downstream(YS 1, YS 2, and YS 3). Contents of organic carbon and calcium carbonates occur being contrary to each other toward upstream. The content of organic carbon increases upstream, that of calcium carbonates decreases. According to size analysis of sediment, the content of gravel increases and mud decreases from downstream to upstream. Sediment deposits can be divided into two types whether gravel is or not. But this boundary is clear in the downstream(YS 1$\sim$YS 4) but is vague in the upstream. The result of this study could be provided engineering, environment, and architecture with geological background as the essential basis.

• Korean Journal of Food Science and Technology
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• v.8 no.4
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• pp.219-224
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• 1976

The appearance of organochlorine pesticide residues in shellfish, seaweed, mud and water samples collected from south coast of Korean peninsula in September 1974 was surveyed to obtain the following results. 1) The residues in shellfish samples were found to be in the orders of Choongmoo > Yeosoo > Busan > Mokpo area, top-shell >short-necked clam > mussel > hard clam > red-shell, aldrin > ${\alpha}-BHC$ > heptachlor> ${\gamma}-BHC$ > dieldrin > heptachlor epoxide > endrin and in the range of $0-49\;{\mu}g/kg$ edible fresh muscle. 2) The residues in seaweed samples from Wando area were found to be in the orders of tangle > green laver > laver, ${\alpha}-BHC$ > ${\gamma}-BHC$ > aldrin > dieldrin > heptachlor > heptachlor epoxide > endrin and in the range of $0-60\;{\mu}g/kg$ dry matter. 3) The residues in water samples were found to be in the orders of Yeongsan River > Nakdong River > Seomjin River > Choongmoo shellfish farm, ${\alpha}-BHC$ > ${\gamma}-BHC$ > aldrin > heptachlor > dieldrin > heptachlor epoxide > endrin and in the range of $0-180\;{\mu}g/kl$ while those in mud samples were in the order of ${\alpha}-BHC$ > ${\gamma}-BHC$> aldrin > dieldrin > heptachlor > heptachlor epoxide > endrin and in the range of $0.7-18\;{\mu}g/kg$ dry matter. It should be noted that BHC contents of water samples from Yeongsan and Nakdong rivers were far above the recommended environmental levels in USA.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.291-298
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• 2001

Seawater, sediment and biota in the Kwangyang Bay were analyzed by gas chromatography/quartz furnace atomic absorption spectroscopy (GC-QFAAS) to investigate concentrations and distribution pattern of butyltin compounds (TBT, DBT, MBT) during February, April and July, 1996, Marine biota analyzed were Tapes japcnicus and Crassostrea gigas. The concentrations of tributyltin (TBT) in seawater were in the range of ND-15.7 ng/L for the surface and ND-68.5 ng/L for the bottom. The highest concentration of TBT in seawater was detected in April for the both, surface and bottom water. The maximum value of $TBT_{(bottom)}/TBT_{(surface)}$, 3.6 in April showed the increased input of TBT from the surface water in April compared to February (2.1) and July (0.9). The concentrations of TBT in the sediment were in the range of ND-8.5 ng/g dry wt. The highest concentration of TBT in the sediment was measured in July, This result seems to attributed to the removal of TBT from water column via sorption onto particulate matters to the relatively undisturbed underlying sediment and increased input of TBT by increased fluxes of detritus of marine plankton after spring bloom, in July. The mean values of partitioning coefficient ($K_d$) of TBT between seawater and sediment were $3.0\times10^3$(February), $7.4\times10^3$(April) and $9.4\times10^3$(July). The concentrations of TBT in biosamples were in the range of ND-93.30 ng/g dru wt. (T. japonicus) and ND-138.53 ng/g dry wt. (C. gigas). The seasonal variation of TBT contents in biota was remarkable. The $K_d$ (biological concentration factor) was $7-41\times10^3$ for T. japonicus. and $5-34\times10^3$ for C. gigas. The measured TBT concentrations in seawater in the study area was sufficient to cause the imposex of shellfish and to retard the growth of aquatic organisms including oyster upon chronic exposure.

• The Korean Journal of Quaternary Research
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• v.16 no.1
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• pp.1-16
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• 2002

A total of 4 muddy sediment samples collected from the Central Yellow Sea were analyzed for chemical composition. The results are compared with the previously published Huanghe, Changjiang and Keum River geochemical data in order to understand provenance and sedimentation of fine-grained mud, and the sediment accumulation rates estimated. The sandy sediment facies is distributed in the eastern area, a patch of fine-grained mud exists in the western central prat, and the sandy mud and clay sedimentary facies shot. north to south zonal distribution in the central region. The content of calcium carbonate ranges from 2.8 to 10.5%, and its distributional trends to be more concentrated on the western muddy sediments near toward the China side rather than on the eastern sandy sediments. The accumulation rates obtained using Pb-210 geochronologies for the muddy sediments in the Central Yellow Sea showed ranges from 0.21 to 0.68 cm/yr or 0.176 to 0.714 g/$\textrm{cm}^2$. yr. The sedimentation rate from core CY96010 located in the eastern near side of Shandong Peninsula which is affected by the Huanghe River shows 0.68 cm/yr or 0.714 g/$\textrm{cm}^2$ . yr. The sediment cores CY96008 and CY96002 in the Central Yellow Sea, the estimated of sediment accumulation rates shows 0.21~0.23cm1yr or 0.176~0.220 9/$\textrm{cm}^2$.Vr respectively, which are much lower than above samples. These indicate that the muddy sediments in central area of the Yellow Sea may have received influence of the sediment discharge from the Huanghe River. The concentrations of Ca, Na, Sr, Ho, La, Tb, Ta and Ca/Ti ratio of the muddy sediments in the Central Yellow Sea are higher than those of the Changjiang sediments and lower than those of the Huanghe sediments. However, these element values showed similar concentration patterns than those of the Huanghe sediment. The element contents such as Fe, Ti, Nl, Co, Cr, Cu, Pb, Sc, Ce, Nd, Sm, Eu, Cd and Dy in the study area are higher than those of the Huanghe sediments and lower than the Changjiang River sediments, but these values showed close to resemblance content trends those of the Changjiang sediment. The concentration of Mn, K and Sr in sediments of the study area are similar to those of the Keum River and eastern Yellow Sea sediment. They are rich in Zn, Rb, Cd, U, Cs and Li than those of the other comparison legions. Therefore, the terrigenous materials sources of the muddy sediment in the Central Yellow Sea comes mainly from Huanghe River in the past and present, and also have party derived from the Changjiang and Keum River, while the biological deposit in this area are carried by the Yellow Sea Warm Current.

• The Korean Journal of Quaternary Research
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• v.7 no.1
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• pp.69-91
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• 1993

A total of 76 surface sediment samples, collected from the Korean west coast and the eastern Yellow Sea areas, were analyzed for their elemental composition in order to understand the geochemical characteristics of these deposits. The analyzed elements included 9 major elements (Al, Fe, Na, K, Mg, Ca, Ti, P, Mn), 8 minor elements (Sr, Ba, V, Cr, Co, Ni, Cu, Zn), organic carbon and calcium carbonate. Contents of most analyzed elements, excluding K and Ba, were generally low compared to those of average crust. Contents of most elements, except K and Ca, also correlated with sediment grain size, though the degree of relationship varied widely from one element to another. For fine-grained sediments, a distinction could be made between those in the central Yellow Sea and those in the Keum Estuary based on their characteristic elemental composition: the former were rich in Fe, Na, K, Mg, Ca and V, and the latter in Mn, Co and Ni. The element/aluminium ratios, on the other hand, showed that the central Yellow Sea muds were enriched in Fe, Mg, V, Ni, Cu and Zn and depleted in K, Mn, Ba and Sr relative to the mud located near the Korean Peninsula. Based on the analysis of these results, as well as of the influences of particular mineral phases or pollution effects, we could suggest geochemical criteria which can be used in distinguishing muds from the two different sources, the Keum River and the Yellow River: the former by the higher Mn content and the latter by the higher Mg and V contents, relative to each other.

• Journal of the Korean earth science society
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• v.24 no.4
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• pp.346-360
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• 2003

In order to investigate the geochemical characteristics of surface sediments in streams of Gwangju City, sediment samples from the main stream of Yeongsan river, Hwangryong river, and Gwangjucheon in the city were collected and analyzed for grain size and metal and organic carbon contents. The sediment types of the streams widely vary from pebble to mud. The metal contents in the sediments from Yeongsan river and Hwangryong river are mainly dependent on the grain size of the sediments and the geology around the streams, while the sediments in Gwangiucheon are controlled by organic matter contents from the domestic sewage. The enrichment factor (Ef) and index of geoaccumulation (Igeo) representing the degree of metal contamination in the sediments are relatively low in the mainstream of Yeongsan river and Hwangryong river. However, those of Gwangjucheon show EF values of P=8.30, Cu=5.54, Zn=14.28 and Pb=7.41 and Igeo values of P=3.78, Cu=2.79, Zn=3.66 and Pb=1.59. The heavy metal contamination is especially significant near the area where the Seobangcheon and Donggyecheon branches of Gwanjucheon, join. Therefore, it is suggested that the metallic contaminations of these small streams are significantly influenced by the domestic sewage of the city.