• The Korean Journal of Quaternary Research
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• v.19 no.2
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• pp.35-37
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• 2005

Sediment samples from five stations at the Shihwa Lake sewage outfall, west coast of Korea, were collected to evaluate the effect of the outfall on benthic foraminifera. Heavy metal (Cu and Zn) polluted eastern part of the Shihwa Lake, adjacent to the Shihwa-Banwol Industrial Complexes, shows barren or nearly barren of benthic foraminifera, and the lowest number of species both at the core top and downcore. Excepting for the barren zone, pyritized benthic foraminifera abundantly occur both at the surface and downcore sediments in the western part of the Shihwa Lake, suggesting that foraminiferal disease by anoxic bacteria. Recent intrusion of pollutants from the Shihwa-Banwol Industrial Complexes and adjacent six major streams severely polluted the Shihwa Lake as shown by the low abundance (number/10 g) of benthic foraminifera, low number of A. beccarii, low species diversity, and absence of both Elphidium spp. and ostracodes at the surface sediments compared to the downcore. Except the barren zone, both pyritized and non-pyritized Ammonia beccarii occur dominantly in the surface sediments and downcore. Elphidium spp. (either pyritized or non-pyritized) do not occur in the surface sediments of whole stations. However, they occur from the entire downcore sediments except in the eastern part of Shihwa Lake. Arenaceous foraminifera do not inhabit in the heavily polluted areas as evidenced by the occurrence of relatively deep core depth (11-50 cm). Ostracodes occur at the downcore sediments, but they do not occur at the surface sediments. Ostracodes also do not occur at the heavily polluted areas in the eastern part of the Shihwa Lake both at the surface and downcore sediments, indicating that the abundance of ostracodes also can be used for a pollution indicator.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• v.26 no.1
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• pp.59-73
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• 1998

Sediment samples from five stations at the Shihwa Lake sewage outfall, west cost of Korea, were collected to evaluate the effect of the outfall on benthic foraminifers. Heavy metal (Cu and Zn) polluted the eastern part of the Shihwa Lake, adjacent to the Shihwa-Banwol Industrial Complexes, shows barren or nearly barren of benthic foraminifers, and the lowest number of species both at the core top and downcore. Excepting for the barren zone, pyritized benthic foraminifers abundantly occur both at the surface and downcore sediments in the western part of the Shihwa Lake, suggesting that foraminiferal disease by anoxic bacteria. Recent intrusion of pollutants form the Shihwa-Banwol Industrial Complexes and adjacent six major streams severely polluted the Shihwa Lake as shown by the low abundance (number/10 g) of benthic foraminifers, low number of Ammonia beccarii, low species diversity, and absence of both Elphidium spp. and ostracodes at the surface sediments compared of both downcore. Except the barren zone, both pyritized and non-pyritized Ammonia beccarii occur dominantly in the surface sediments and downcore. Elphidium spp. (either pyritized or non-phyritized) do not occur in the surface sediments of whole stations. However, they occur from the entire downcore sediments except in the eastern part of Shihwa Lake. Arenaceous foraminifers do not inhabit in the heavily polluted areas as evidenced by the occurrence of relatively deep core depth (11-15 cm). Ostracodes occur at the downcore sediments, but they do not occur at the surface sediments. Ostracodes also do not occur at the heavily polluted areas in the eastern part of the Shihwa Lake both at the surface and downcore sediments, indicating that the abundance of ostracodes also can be used for a pollution indicator.

• Journal of Aquaculture
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• v.18 no.3
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• pp.200-206
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• 2005

We previously pointed out that the polluted sediment elutriate manifestly affected the early events of reproductive outputs in the Pacific oysters, Crassostrea gigas. A serial dilution of priority xenobiotic sediment elutriates determined by gas chromatography/mass spectrometry (GC/MS) were exposed to gametes of the oyster with different stress burdens to detail the maternal stress transfer to its reproductive outputs. There was an apparent critical concentration over which survival and morphogenesis were significantly affected with more profound damage in morphogenesis. The critical concentration which drives mortality and abnormal morphogenesis of the larvae corresponded to a dilution between 10 and 20% of our elutriate. The adverse effects of the early lives by the xenobiotic exposure over the critical concentration were magnified by the maternal stress from the exposed benzo(a)pyrene (BaP), one of the priority polyaromatic hydrocarbons (PAHs) during the maturation condition. These results indicate that maternal transfer of the xenobiotic compounds from oysters living in the contaminated location might represent a significant adverse effect to their larval population of wild seeds.

• Economic and Environmental Geology
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• v.26 no.2
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• pp.217-226
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• 1993

Stream sediment samples were collected in the vicinity of the Sambo Pb-Zn-barite mine in order to investigate dispersion patterns and pollution levels of heavy metals, and to find out their mode of occurrences. Those samples were analyzed for Cd, Cu, Pb, Zn, Fe, and Mn by using partial extraction and sequential extraction methods. Stream sediments of this studied area has been contaminated severely by Pb, Zn, and Cd. Dispersion patterns of heavy metals in those sediments are different according to their pollution source and sampling distance from the mine. The stream sediment pH is generally neutral in control area, and is slightly acidic in the lower part of tailing dam. The main pollution source of stream sediments was confirmed as tailing and mine drainage. Their pollution level depends mainly on inflowed water and distance from the mine. The tolerance index ranges from -0.9 to 0.7. The mode of occurrances of heavy metals in polluted stream sediment are identified as Fe-Mn oxides, organic bounded and carbonate-bounded compound which show high potential of bioavailablity.

• Journal of the Korean Society for Marine Environment & Energy
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• v.1 no.1
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• pp.83-92
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• 1998

Heavy metals concentration in superficial sediment of effluent discharging area was rapidly increased by annual loadings of Zn(8.465 Kg), Ni(3,291 Kg), Cu(1,636 Kg) and Pb(1,250 Kg) from sewage effluent of 63×10/sup 6/ m³/yr. In a consequent result, specially the concentrations of Zn and Cu in the sediment were three times higher than preindustrial reference values. The evaluation by multiple ecological risk indices showed that heavy metals contamination in sediment of discharging area was 'heavily Polluted level' by sediment quality criteria and increased 2.6 times by the degree of contamination. It was also judged that toxicological effects of sediment receiving the primary effluent would occasionally (16～47%) occur by guidelines for adverse biological effect.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.504-510
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• 2014

In this study, physico-chemical properties and pollution degree of surface sediments collected at 5 stations(S1~S5) of Incheon H wharf in March 2014 were investigated. From particle size, surface area, XRD and XRF analyses, the sediment samples consisted of similar oxides and minerals. Considering total score of COD, AVS and IL, pollution level ranged between 2 and 3 based on domestic standards. In case of heavy metal contamination, Cd, Ni and Pb were classified as moderately polluted by USEPA standards. However, Cu, Zn and Cr were classified as heavily polluted. With geoaccumulation index value($I_{geo}$), Cd contamination was estimated as class 3. In addition, the calculated enrichment factors of Cd, Pb and Zn were exceeded a value of 1. Site S4 was high as 3.1 in total enrichment factor.

• Journal of Environmental Science International
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• v.24 no.8
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• pp.969-980
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• 2015

In order to certificate the distribution and pollution of heavy metal of surface sediments in Nakdong River were collected and analyzed for grain size, water content, ignition loss and heavy metal content. Surface sediments mainly composed of sand(avg. 94.6%) and water content and ignition loss were 20.46%, 1.53% on average. Grain size were relatively fine and organic matter content were relatively high in the Hoichun and Sunakdonggang. Most of heavy metal content(Zn > Cr > Pb > Ni > Cu > Hg) in the Deokcheongang and Sunakdonggang were higher than the other streams. The Igeo were non polluted(less than 0) in all streams and the EF were relatively high in the small stream and PLI were non polluted(less than 1). In addition, organic matter, heavy metal content and pollution were highly correlation with grain size. Surface sediments in study area, heavy metal pollution of the Sunakdonggang were relatively high compared to the other stream but these results were not serious pollution that exceed the sediment pollution evaluation standard of river and lake in Korea and pollution levels adversely affected the majority of benthos were not.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.311-324
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• 2017

To certificate change in the geochemical characteristics of surface sediments in the main stream of the Nakdong River, surface sediments from 12 sampling sites during the first and second half year (total 24 sampling sites) were collected and analyzed for grain size, ignition loss, total organic carbon and heavy metal content. Surface sediments mainly composed of sand (coarse and medium sand) and fining changed from the first half to the second half of the year. Ignition loss, total organic carbon and heavy metals content increased in the second half of the year. Some heavy metals (Zn, Ni and Cu) were found to be at the lowest effect levels according to Ontario sediment quality guidelines. Additionally, most heavy metals were found to be at the non polluted level and level I according to USEPA sediment quality standards and National Institute of Environmental Research sediment pollution evaluation standard, respectively. The enrichment factor (< 1) and index of geoaccmulation (< 0) were non polluted in the study area. The correlation analysis results showed that ignition loss, total organic carbon and heavy metal content were highly correlated with grain size. Regarding changes in geochemical characteristics of surface sediments in the study area, grain size fine and organic matter and heavy metal content increased in the second half year. Nonetheless these results indicated pollution levels that did not adversely affect the benthos.

• Journal of Microbiology and Biotechnology
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• v.29 no.7
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• pp.1104-1116
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• 2019

In this study, we investigated the potential of using sediment bioelectrochemical systems (SBESs) for in situ treatment of the water and sediment in brackish aquaculture ponds polluted with uneaten feed. An SBES integrated into a laboratory-scale tank simulating a brackish aquaculture pond was established. This test tank and the control (not containing the SBES) were fed with shrimp feed in a scheme that mimics a situation where 50% of feed is uneaten. After the SBES was inoculated with microbial sources from actual shrimp pond sediments, electricity generation was well observed from the first experimental week, indicating successful enrichment of electrochemically active bacteria in the test tank sediment. The electricity generation became steady after 3 weeks of operation, with an average current density of $2.3mA/m^2$ anode surface and an average power density of $0.05mW/m^2$ anode surface. The SBES removed 20-30% more COD of the tank water, compared to the control. After 1 year, the SBES also reduced the amount of sediment in the tank by 40% and thus could remove approximately 40% more COD and approximately 52% more nitrogen from the sediment, compared to the control. Insignificant amounts of nitrite and nitrate were detected, suggesting complete removal of nitrogen by the system. PCR-DGGE-based analyses revealed the dominant presence of Methylophilus rhizosphaerae, Desulfatitalea tepidiphila and Thiothrix eikelboomii, which have not been found in bioelectrochemical systems before, in the bacterial community in the sediment of the SBES-containing tank. The results of this research demonstrate the potential application of SBESs in helping to reduce water pollution threats, fish and shrimp disease risks, and thus farmers' losses.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.67-73
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• 2019

We carried out basic research to evaluate covering material for improving and managing contaminated benthic environments in coastal areas. Changes in nutrient concentration such as phosphate, hydrogen sulfide of contaminated sediment, and pH, Oxidation Reduction Potential (ORP) were investigated through mesocosm experiments for 6 months by covering contaminated sediment with granulated coal ash. Calcium oxide eluted from the granulated coal ash was confirmed to neutralize acidified sediment by increasing pH through hydrolysis. Also, calcium oxide and silica eluted from the granulated coal ash adsorbed and precipitated with phosphate in the sediment. The concentration of phosphate in the sediment investigated decreased by ca. 84.31 %. Similarly, the concentration of hydrogen sulfide decreased by 133.5 mg/L in one month. The hydrogen sulfide is considered to have reacted with substances such as manganese oxide which were eluted from the granulated coal ash and precipitated. Also, it was concluded that the hydrogen sulfide was reduced since anaerobic conditions in the sediment weakened. According to the results of these mesocosm experiments, granulated coal ash was found to be effective to remediate and manage benthic environments by covering the surface layer of sediment.