• The Korean Journal of Quaternary Research
• /
• v.5 no.1
• /
• pp.15-31
• /
• 1991

A total of 90 surface sediment samples, collected from the continental margin area bordering east and southeast coast of Korea, were subject to the geochemical analyses with the aim of filling the gap in our knowledge of this environment. The analyzed items included the major elements (Al, Fe, Mg, Ca, K, Na, p and Mn), organic carbon, and some trace metals (Ba, Co, Cu, Sr and Zn). The sediment grain-size exerted a predominant influence on the contents of most elements, with the exceptions of Ca, K, Sr and Ba. The Ca and Sr contents, being closely interrelated each other, were mainly controlled by the calcium carbonate content. The K content, on the other hand, appeared to be influenced by both illite and feldspar. The Ba content showed a certain relationship with that of K, suggesting a common source of these two elements; potassium feldspar. The R-mode factor analysis result also reaffirmed the above-mentioned controlling factors on the sediment geochemistry. The grain-size dependency of trace metals obscures their areal distribution pattern from the total contents. However, with the metal/aluminum ratios we could differentiate the subtle difference in the metal enrichment. Hence, sediments of the southern coastal area appear to receive some anthropogenic inputs of metals, though the effect is still negligible.

• 한국해양학회지
• /
• v.30 no.5
• /
• pp.382-389
• /
• 1995

This study intended to investigate the sedimentation rates of core sediments of the western part of the East Sea using Accelerator Mass Spectrometer (AMS) C-age on the planktonic foraminifera or acid-ex-tracted residue, base-soluble and base-extracted residue fractions. On the basis of the depth-age correlations, the sedimentation rates during the late Holocene period of Cores HP-10, HP-3, 94-9 and 92-3 were 30 cm/kyr, 10 cm/kyr, 11 cm/kyr and 112 cm/kyr, respectively. The sedimentation rates of the westem part of the East Sea, however, seems to be ranged from 11 cm/kyr to 30 cm/kyr, because the rates of the only two cores (Cores HP-10 and 94-9) which were dated at more than three depths are considered to be more reliable. The rates in each core sediment showed good linear relationship with the sample depth, suggesting that the sea-level rise had been finished nearly during the early Holocene period and the general depositional environments had been lasted rather constant during the late Holocene period.

• Proceedings of KOSOMES biannual meeting
• /
• 2008.05a
• /
• pp.159-164
• /
• 2008

In order to understand the spatio-temporal distribution of geochemical parametrs in surface sediments of the artificial Lake Shihwa in the vicinity of Kyunggi Hay in Korea, surface sediments were sampled at 14 sites in July 2007 and analyzed by CHN analyzer and ICP/MS. Metal concentrations in the sediments tended to be decreasing from the head to the mouth of the Lake Shihwa because of extreme pollutant discharge from various kinds of anthropogenic sources such as the Banweol and Shihwa Industrial Complex and cities. With the deposition of fine-grained sediments, high metal concentrations were also observed in the central part of lake. Although various programs(improvement of wastewater collection and treatment system, sea-lake water exchange etc) to improve the environmental conditions around the Lake Shihwa after dike construction were carried out, it was not dear to reach a good environmental quality. Therefore, further environmental programs should be conducted continuously for environmental improvement.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.3 no.2
• /
• pp.3-10
• /
• 2000

The main purpose of this study were to estimate the benthic fluxes of dissolved inorganic nitrogen (DIN) from the sediment and denitrification rates in tidal flats of the Keum river estuary. Sediment specimens were collected by a core sampler from three stations along the Keum river estuary in April, August and December, 1999. The sediments were composed of 1.18 %, 29.34 % and 69.49 % of gravel and sand, sand and silt, respectively. The mean ignition loss of the sediment was found 6.7 % and its Oxidation Reduction Potential (ORP) was measured -12 mV. The total hydrogen sulfides was determined about 0.26 mg/gㆍdry. The estimated outflux of ammonium was found 11.2 m mole N/m²ㆍday from the sediment, whereas -1.09 m mole N/m²ㆍday of influx was obtained for nitrate and nitrite through the incubation experiment of sediment cores. Total DIN flux was 10.2 m mole N/m²ㆍday outflux from the sediment. From the incubation experiments executed with the flux studies, mean denitrification rate was found 30.6 m mole N₂/m²ㆍday measured by the direct assay of N₂ production technique. On the basis that DIN flux and denitrification rate in sediment of tidal flat of the Keum river estuary are may be effects to control the algal biomass in the coastal environment, it seems inevitable to pay more attention to investigate the flux of DIN and denitrification rate in tidal flat of the Keum river estuary.

• Journal of the Mineralogical Society of Korea
• /
• v.19 no.4 s.50
• /
• pp.291-300
• /
• 2006

This study has been carried out to reveal the mineralogical compositions, the concentrations of heavy metals, and related factors in the sediments of the Kumho River which is the main tributary of the Nakdong River. Even though this river flows in a short distance, it runs through different geology and industrial areas and can be a good candidate to study different geological and anthropogenic factors affecting the concentrations of heavy metals in the sediment. The major rock-forming minerals were quartz and albite. Minor amount of orthoclase, microcline, and amphybole were also identified. Clay minerals including illite, chlorite, kaolinite were associated with those minerals. In the downstream, no noticeable changes in species and amount of minerals were observed, indicating there is almost no influence on the mineralogical compositions from rock types. The concentrations of heavy metals in the sediments are in the order of Zn > Pb > Cu > Ni > Cr > Co > Cd. Following the downstream, the concentrations of heavy metals generally increase, except Pb. The regional increase of the heavy metal content is well correlated with the location of the tributary. Without changes in mineral compositions, the main factors controlling the heavy metal contents are the locations of pollutant sources. Except Pb and Ni, most of the concentrations of heavy metals were thought to be enriched by the past pollutant sources.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.14 no.3
• /
• pp.171-180
• /
• 2009

Based on the constituent analysis of sediments near Dok Island, the origin and sedimentary facies were Investigated. The sediments are mainly from originated from volcanic and volcaniclastic rock fragments derived from Dok Island and carbonate sediments formed by a variety of shallow-dwelling organisms that secreted calcareous skeletons. Carbonate producers include mollusks (bivalves and gastropods), encrusting & branching bryozoans, encrusting & segmented red algae, worm tubes, barnacles, diatoms, sponge spicules and echinoderm fragments. The distribution and relative amount of these constituents are basically dependent upon water depth and grain size even though local variations can be observed within the same depth interval. Five sedimentary facies can be divided: nearshore facies (<20 m), neritic facies ($20{\sim}100m$), upper transitional facies ($100{\sim}200m$), lower transitional facies ($200{\sim}700m$), and hemipelagic facies (>700 m). The sediments that were sampled below the water depth of 2,000 m still contain a significant amount of carbonates (ca. $10{\sim}20%$), implying that the carbonate compensation depth in the East Sea may well exceed this water depth.

• The Korean Journal of Malacology
• /
• v.28 no.3
• /
• pp.225-232
• /
• 2012

In order to evaluate the relationship of between the contents of inorganic elements in shellfish and surface sediments, we measured the concentration of inorganic elements (As, Ca, Cd, Cr, Fe, Hg, Li, Mn, Ni, P, Pb, Zn) in various shellfish and surface sediments of research area. The enrichment factor (EF) and the index of accumulation rate (Igeo) of the metals showed that the research areas can be classified as moderately polluted, or unpolluted. And also we measured the geochemical characteristics of surface sediments(grain size, chemical oxygen demand (COD), ignition loss (IL) and acid volatile sulfide (AVS). The grain sizes for research areas of surface sediment were similar the ratio of silt and clay in comparison with other sites. The COD and IL in surface sediment ranged from 5.41 to 14.06 mg/g. d.w. (mean $8.78{\pm}3.16$ mg/g d.w.) and from 0.92 to 3.17% (mean $2.08{\pm}0.86%$), respectively. Siginificant differences in metal concentrations also were determinated in the shellfish tissue among the different sites. However, except for metals(Mn, Zn), which showed some elevation of concentrations, the variations in the shellfish tissue were not related to variations in the sediment.

• Journal of the Mineralogical Society of Korea
• /
• v.20 no.1 s.51
• /
• pp.47-60
• /
• 2007

While sedimentological researches on Western coastal tidal flats of Korea have been much pelformed previously, mineralogical and biogeochemical studies are beginning to be studied. The objectives of this study were to investigate mineralogical characteritics of the inter-tidal flat sediments and to explore phase transformation of iron(oxyhydr)oxides and biomineralization by metal-reducing bacteria enriched from the inter-tidal flat sediments from Muan, Jeollanam-do, Korea. Inter-tidal flat sediment samples were collected in Chungkye-myun and Haeje-myun, Muan-gun, Jeollanam-do. Particle size analyses were performed using the pipette method and sedimentation method. The separates including sand, silt and clay fractions were examined by scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), and X-ray diffiaction (XRD). After enriching the metal-.educing bacteria from the into,-tidal flat sediments, the bacteria were used to study phase transformation of the synthesized iron (oxyhydr)oxides and iron biomineralization using lactate or glucose as the electron donors and Fe(III)-containing iron oxides as the electron accepters. Mineralogical studies showed that the sediments of tidal flats in Chung]rye-myun and Haeje-myun consist of quartz, plagioclase, microcline, biotite, kaolinite and illite. Biogeochemical researches showed that the metal-reducing bacteria enriched from the inter-tidal flat sediments reduced reddish brown akaganeite and mineralized nanometer-sized black magnetite. The bacteria also reduced the reddish brown ferrihydrite into black amorphous phases and reduced the yellowish goethite into greenish with formation of nm-sized phases. These results indicate that microbial Fe(III) reduction may play one of important roles in iron and carbon biogeochemistry as well as iron biomineralization in subsurface environments.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.10
• /
• pp.4047-4054
• /
• 2010

We studied the release characteristics of the marine sediment which could facilitate sea eutrophication through some lab-scale simulation experiments. Environmental indicators such as pH, ORP(oxidation reduction potential), nitrogens, and phosphates were measured in order to calculate the corresponding release rates. $CaO_2$, an oxygen releasing compound was used to determine how it would effect on the natural process of sedimental release. COD, ammonia nitrogen, phosphorous compounds were less released under the oxic environment caused by $CaO_2$. This basic data will help developing methodology for reducing marine eutrophication which may be initiated by the sedimental release.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.7
• /
• pp.469-475
• /
• 2014

The study investigated the physicochemical characteristics and the ecological risk of the Northport sediment in B city and the releasing properties of heavy metals into seawater during the resuspension also studied. The major components of the sediment are fine silt and clay which contains high organic matter and AVS (Acid volatile sulfide) and the ecological risk of the heavy metals in sediment also very high. The release rate of heavy metals into seawater was in order of Pb>>Cu>Cr>>Zn>Cd during the resuspension in a batch experiment, and the heavy metal release mainly attributed to the oxidation of metal sulfides. Heavy metals which came from easily oxidisable metal sulfides rapidly contaminated seawater within about 1.0 h of the sediment resuspension. The sulfide oxidation during the resuspension increased the residual fraction of heavy metals in the sediment, decreased the organic bound fraction, and changed the other fractions of heavy metals in the sediment. The release of heavy metals from the sediment during resuspension was affected by the resuspension time, the oxidation rate of metal sulfides and resuspended concentration of the sediment particle.