• Journal of Korean Society of Environmental Engineers
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• v.37 no.2
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• pp.99-106
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• 2015

To estimate the effects of suspended sediments flowing into the Saemangeum Reservoir on the extent of contamination of the reservoir, the suspended sediments were collected with sediment traps, which were installed from the upstream of the Mankyung and Dongjin Rivers to estuary of the reservoir, respectively, and the sedimentation rates and the chemical characteristics of suspended sediments were analyzed. The sedimentation rates in the Mankyung and Dongjin Rivers were ranged from 0.01~5.06 and $0.01{\sim}8.75kg/m^2/day$, respectively. Those were higher to the upstream of rivers, and were mainly affected by flood events. The concentrations of organic matters were from 3.3 to 9.6 times higher than those in the stream sediments and were higher after flood season, indicating the contaminants come from the non-point sources on the basin. The concentrations of total nitrogen and total phosphorus in the suspended sediments showed the same trend with the organic matters. These results indicate that the suspended sediments from the basin of the Mankyung and Dongjin Rivers are highly contaminated and the countermeasures to manage the sources of contamination on the basin are required to maintain the water quality of the Saemangeum Reservoir.

• The Korean Journal of Quaternary Research
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• v.14 no.1
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• pp.7-31
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• 2000

Quaternary Geological and geophysical investigation was performed at the Eurimji reservoir of Jaechon City in order to interprete depositional environment and genesis of lake sediments. For this purpose, echo sounding, bottom sampling and columnar sampling by drilling on board and GPR survey were employed for a proper field investigation. Laboratory tests cover grain size population analysis, pollen analysis and $^{14}C$ datings for the lake sediments. The some parts of lake bottom sediments anthropogenically tubated and filled several times to date, indicating several mounds on the bottom surface which is difficult to explain by bottom current. Majority of natural sediments were accumulated both as rolling and suspended loads during seasonal flooding regime, when flash flow and current flow are relatively strong not only at bridge area of the western part of Eurimji, connected to stream valley, but at the several conduit or sewage system surrounding the lake. Most of uniform suspend sediments are accumulated at the lake center and lower bank area. Some parts of bottom sediments indicate the existence of turbid flow and mudflow probably due to piezometric overflowing from the lake bottom, the existence of which are proved by CM patterns of the lake bottom sediments. The columnar samples of the lake sediments in ER-1 and ER-3-1 boreholes indicate good condition without any human tubation. The grain size character of borehole samples shows poorly sorted population, predominantly composed of fine sand and muds, varying skewness and kurtosis, which indicate multi-processed lake deposits, very similar to lake bottom sediments. Borehole columnar section, echo sounding and GPR survey profilings, as well as processed data, indicate that organic mud layers of Eurimji lake deposits are deeper and thicker towards lower bank area, especially west of profile line-9. In addition the columnar sediments indicate plant coverage of the Eurimji area were divided into two pollen zones. Arboreal pollen ( AP) is predominant in the lower pollen zone, whreas non-aboreal pollen(NAP) is rich in the upper pollen zone. Both of the pollen zones are related to the vegetation coverage frequently found in coniferous and deciduous broad-leaved trees(mixed forest) surrounded by mountains and hilly areas and prevailing by aquatic or aquatic margin under the wet temperate climate. The $^{14}C$ age of the dark gray organic muds, ER1-12 sample, is 950$\pm$40 years B.P. As the sediments are anthropogenetically undisturbed, it is assumed that the reliability of age is high. Three $^{14}C$ ages of the dark gray organic muds, including ER3-1-8, ER3-1-10, ER3-1-11 samples, are 600$\pm$30 years B.P., 650$\pm$30 years B.P., 800$\pm$40 years B.P. in the descending order of stratigraphic columnar section. Based on the interpretation of depositional environments and formation ages, it is proved that Eurimji reservoir were constructed at least 950$\pm$40 years B.P., the calibrated ages of which ranges from 827 years, B.P. to 866 years B.P. Ancient people utilize the natural environment of the stream valley to meet the need of water irrigation for agriculture in the local valley center and old alluvium fan area.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.324-333
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• 1997

The research has been made for the effects of the pollution by the abandoned coal mine drainage on the physical and chemical properties of soil, stream sediment and soil water. The soils overspreaded by the abandoned coal don't develop solum and the bulk density is $1.83g/m^3$, compared with $1.14-1.38g/m^3$ in the other forest soils. The soil pH range in coal bearing region ie, from 4.01 to 4.11 and non-coal bearing soil range is from 5.03 to 5.13. Heavy metals such as As, Cr, Ni, Mo and Ba of coal bearing soils and polluted stream sediments have larger concentration than those of non-coal content and non-polluted. Especially As and Mo concentrations are largely high in coal bearing. The relative ratios $K_2O/Na_2O$ of geochemical elements are higher in coal bearing soil and polluted stream sediments than those of non-coal bearing soils and non-polluted stream sediments as well as black shales of the Changri Formation. However, $MgO+Fe_2O_3+TiO_2/CaO+K_2O$ are the opposite trends, so that the ratios are lower in the polluted regions. The soil water pHs in the polluted regions are the strong acid(pH3.4-4.2) and buffer capacity of the polluted soil is low because canons such as $Na^+$, $K^+$, $Mg^{+2}$are leached by the acidification.

• Journal of Korea Soil Environment Society
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• v.3 no.3
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• pp.33-44
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• 1998

Mine tailings, soils, stream sediments, and ground water around Imcheon disused mine were analyzed in order to investigate their pollution levels of heavy metals and cyanide. The average contents of As, Cd, Cu, Hg, Pb, Zn, and CN￣ in mine tailings were 366, 28.8, 202, 15.2, 1.97$\times$$10^3$, 3.85$\times$$10^3$, 90.6mg/kg respectively, The pollution indices that calculated by the tolerance level of Kloke were 8~19 and the pH values were acidic in mine tailngs. In the field and paddy soils of Imcheon disused mine area except for soils nearby mine tailngs, concentraitons of the heavy metals were less than standards of soil pollution of agricultral area in the environmental protection law. The nitrate contents In the ground water for drink were more than tolerance level of the drinking water of Ministry of Health and Social Affairs.

• Water for future
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• v.24 no.2
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• pp.71-79
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• 1991

Some selected hydraulic characteristics including the average velocitv, geometry of the channel cross-section, and water temperature, and sediment-characteristics including suspended sediment concentration , and the size distributions of suspended and bed-sediments were collected at two measuring stations in the Cheongmi-Stream during a flood period. The river bed investigated for this study is composed completely of sands, and it can be considered a typical alluvial channel. The major results obtained from the analysis of the date collected are as follows: 1) Only during floods, a substantial sediment transport occurs in the river; 2) The stage-discharge relations are changed frequently, especially for low flows; 3) The friction in the flow increases with an increase in the flow discharge; 4) Slits and clays are dominant in suspended sediments during normal flows, while sands are dominant during floods; 5) The vertical distributions of the flow velocity and suspended sediment concentration can be described, respectively, by Prandt1-von Karman's log-law and Rouse's exponential law. It is judged that the above results are commonly adapted for other alluvial rivers, although they were obtained from a limited number of data collected from a specific river reach.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.107-114
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• 2007

This study aimed to investigate the hexachlorobenzene (HCB) dechlorinating ability of sediment microbes collected from a natural canal receiving secondary effluents from an industrial estate and nearby factories. Nine sites along the stream and one in the estuary in the Gulf of Thailand into which the canal spills were specified and sampling for sediment and water. Preliminary analysis of the sediments showed that the first four sites nearest to the discharging location were contaminated by HCB within the range of 0.18 to 1.25 ppm. Apart from that, 1,3,5-trichlorobenzene which has never been commercially produced or used in any manufacturing processes except for the transformation from higher chlorinated benzene was also identified in the range of 0.16 to 0.24 ppm. This suggested a possibility of sporadically HCB contamination in this stream. Of more important, people in the community along this canal earn their living by coastal fishery; hence, posing a risk of spreading HCB and its less chlorinated congeners via food chain from caught marine creatures to human. As a result, there is an urgent need to understand the behavior of HCB dechlorination in this stream sediment which can lead to a clean-up action in the future. Serum bottles with sediment slurries (sediment to water ratio of 1:1 (v/v) and filtered to remove particles larger than 0.7 mm) from each site were inoculated with 2 mg/l of HCB, kept anaerobically in the dark at room temperature without any nourishment, and analyzed for HCB and its less-chlorinated congeners every 6 days. Total chemical oxygen demand, suspended solids, and volatile suspended solids were in the range of 21,492-73,584, 158,100-518,100 and 6,000-32,700 mg/l, respectively. It was found that all sediment slurries began to dechlorinate HCB in 12 to 30 days and the HCB was completely removed within 42 to 60 days or so. On the other hand, there was no HCB dechlorination occurred in the controlled set which was sterilized by autoclaving prior to the addition of HCB. This implies that the HCB transformation was solely due to microorganisms' activities. HCB was dechlorinated principally via pentachlolobenzene to 1,2,3,5-tetrachlorobenzene and terminated at 1,3,5-trichlorobenzene which is the major pathway as reported by many researchers. Dichlorobenzene has not been detected in any samples within the dechlorination period of 60 days. The results indicate that the microbial matrix in the sediment of this stream has an outstanding capability to dechlorinate HCB. Existing substrates and nutrients which mainly sorbed onto the solid phase and the typical temperature in Thailand were sufficient and suitable to promote the activities of these HCB-dechlorinating microbes.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.45-55
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• 1996

Although the Dongjin Au-Ag-Cu mine had been abandoned since about forty years ago, the results of this study on the dispersion patterns and contamination level of heavy metals in the hydrologic system flowing via the waste rump show that the environmental impacts from the mine wastes are still significant. The stream water in the vicinity of the waste rump is severely acidified (pH 3.8 to 4.4) and highly enriched in various dissolved heavy metals. The heavy metal contents of the stream water and stream sediments are systematically attenuated with increasing distance from the mine area. However, it is worth to note that continuous attenuation of heavy metal contents in both media were reenriched in downstream area more than 800 m apart from the mine because it can be acted as a secondary source of heavy metal pollution. The heavy metals, especially Cd, Cu and Zn of polluted downstream sediments mainly occur in Fe-Mn oxides and organic materials, which indicates that these elements are the main pollutants from the waste rump of the Dongjin mine. The heavy metal contents of crops, such as sesame, perilla, red Pepper and brown rice, collected from the polluted farm land in the downstream area are lower than those of land plants from stream sides, but significantly higher in Cd, Cr, Cu and Zn than those from the unpolluted farm land. Especially, almost all of the crops in polluted farm land have been severly contaminated by Cd (>0.4 ppm). On the other hand, the heavy metal contents of the crops collected from refreshed farm land by means of a soil addition method shows significantly lowered level comparing with those of polluted area, which indicates that a soil addition method was effective for the refreshment of polluted farm land by toxic metallic pollutants. Wormwoods from this area showed very high contents in a11 the heavy metals even in unpolluted area (Cd > 1 ppm, Cr > 1 ppm, Cu > 11 ppm, Pb> 4 ppm, Zn > 55 ppm), indicating that a special caution must be payed when one takes ingest them.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.11
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• pp.809-814
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• 2013

In this study, physical properties and heavy metal contents of sediments obtained from the bottom of Gwangan bridge were measured to determine pollution level of the sediments. From the results of the oxide contents of the sediments, $SiO_2$ was decreased as the sampling points became more distant from the stream of river. On the contrary, CaO showed opposition aspect to $SiO_2$. Ignition loss of sediments ranged from 7.2 and 14.3% and 0.9 and 5.5% for TOC. For EPA guidelines of ignition loss, all sampling points were classified as heavily polluted areas. When TOC was considered, all areas were classified as lowest effect level except for GW7 where classified as no effect level. All areas were free of heavy metal contamination evaluated by USEPA and Canadian guidelines. However, all areas were classified as heavily contaminated areas due to the high value of ignition loss when USEPA was used.

• 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.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.298-301
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• 2000

Heavy metals are extracted from stream sediments, roadside soils and sediments and soils and tailings from mining area using partial extraction, acid digestion and HF-digestion. Compared to amounts of heavy metals extracted using partial extraction, those extracted using acid digestion are higher by 2.0∼220.9 times in Cu, 2.4∼2806.1 times in Pb, 1.3∼121 times in Cd, 14.1∼1300885 times in Fe, 1.2∼271.5 times in Mn, 1.3∼372.5 times in Zn, 2.2∼1734.5 times in Cr. Although partial extraction, which extracts less amounts of heavy metals from soil compared to acid digestion, is used in domestic standard method for examination of soil, domestic soil standard for heavy metals in non-agricultural and industrial areas is higher than soil standard in foreign countries which use acid digestion, For improvement of the domestic standard method for assessment of soil, it is suggested to lower the domestic soil standard for heavy metals or to change pretreatment method for extracting heavy metals from partial extraction to acid digestion with modifying the soil standard.