• Journal of Korean Society of Water and Wastewater
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• v.29 no.2
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• pp.211-222
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• 2015

This study focused on evaluating the efficiency of the removal of non-point source pollution by Daecheong Lake Juwon Stream constructed wetlands. The constructed wetland system is a surface flow type designed in the year 2007 for purifying eutrophic water of Daecheong Lake Juwon Stream. The value of conductivity, suspended solids(SS), chemical oxygen demand using a potassium permanganate($COD_{Mn}$), five-day biochemical oxygen demand($BOD_5$), total nitrogen(T-N), total phosphorous(T-P), and pH in inflow averaged 220.2, 2.46, 3.33, 1.34, 2.00, 0.04 mg/L and 7.24, respectively and in outflow averaged 227.9, 1.12, 3.34, 0.87, 1.16, 0.02 mg/L and 7.45, respectively. The average removal efficiency of constructed wetlands was 30 % for SS, 22 % for $BOD_5$, 45 % for T-N and 31 % for T-P. The removal rates of SS, $BOD_5$ and T-N in the spring, summer and autumn were higher than those in winter. The removal rate of T-P was not significant different in all seasons. The amounts of pollutants removal in the constructed wetlands were higher in the order of $3^{rd}$ < $2^{nd}$ < $1^{st}$ wetland for SS and T-P, $2^{nd}$ < $3^{rd}$ < $1^{st}$ wetland for $BOD_5$ and T-N. Therefore, our findings suggest that the constructed wetlands could well treat the eutrophic Daecheong Lake Juwon Stream waters.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.5
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• pp.783-790
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• 2011

The purpose of this study was to suggest the alternative measures to properly manage the water quality of Lake Euiam, Chuncheon. Current pollution level of Gongji stream (influent to Lake Euiam) and sources of contamination in Lake Euiam were investigated. Particle size, organic matter and nutrient contents, heavy metals were analyzed for sediment samples taken from lower region of Gongji stream. Average organic matter content of nine sediment samples was 5.7%, and for nitrogen and phosphorus it was 750 mg/kg and 977mg/kg, respectively. Heavy metals including aluminum, iron, manganese and zinc were measured, whereas Cd and As were not detected. Effluent from Chuncheon Wastewater Treatment Plant appeared to be one of the main cause of organic matter and nutrients level in Lake Euiam. Inhibition of primary production and consequent reduction of organic matter content within the Lake should be a key measure to protect the water quality of Lake Euiam. Preventive measures to reduce the level of nutrients in wastewater treatment effluent were found necessary.

• Journal of Wetlands Research
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• v.10 no.2
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• pp.115-128
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• 2008

Various human activities such as the Urbanization and Industrialization are estimated the main factors to pollute the stream. Now days, numerous studies are carried out for managing non-point sources which have un-effect on water quality of streams by land-use and livestock. In case of Korea, a matter of concern that the management of Pal dang reservoir - the main water resources of the national capital region - has been occurring. Especially, large-scale constructed-wetlands are planned and constructed at the end of Kyoung-an stream. Additionally a lot of sewage treatment plants are newly installed and extended in this watershed. According to these efforts, water quality of Kyoung-an stream is predicted that would be improved. But the more detail and scientific analysis should be carried out for the water quality improvement, because, existing water quality improvement projects are not involved to analyze root of water quality deterioration and improvement plans. Therefore, this study aims to select suitable areas for constructed-wetlands and to calculate size of the constructed-wetlands for water quality improvement in Kyoung-an stream through the geographical pollutant distribution analysis and land-use pattern analysis by high resolution satellite image and suitable area analysis of constructed-wetlands by GIS(Geographic information system). The progress of this study is (1) to select maximum pollutant loaded area by geographical analysis based on water quality data, (2) to analyze land-use patterns using high resolution satellite image, (3) to select suitable areas of constructed-wetlands, (4) to calculate area and volume of chosen constructed-wetlands using GIS. Basically, sizes of constructed-wetlands are induced through the constructed-wetlands design index based on treatment ratio(provided by Korea Water Resources Corporation). As a result of this study, two areas are selected to construct constructed-wetlands. One of the area was $127,586m^2$ near by Yong-in sewage treatment plant, and the other area was $1,647m^2$ near by Ju-buk stream and Dae-dae stream.

• Clean Technology
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• v.7 no.4
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• pp.251-263
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• 2001

This study was conducted to provide a basic information for recovery plan of Seung-Gi Stream which is a major stream of Incheon metropolitan area. Source and characteristics of pollutants were analyzed and studied. Samples were taken 10 rounds in 5 sections in Seung-Gi stream. Annual pollutants loads and sectional characteristics of pollutants loads were investigated regarding flow rate, pH, DO, SS, $BOD_5$, $COD_{Cr}$, T-P, TKN and concentrations of Zn, Cd, Cu, Cr atoms which enter into Seung-Gi stream during rainy and dry season respectively. As one came close to the Nam-Dong Industrial Complex, sectional discharge loads were heavy and water quality was failed to meet the standard by "Environmental Standard of River Quality". As a result, heavy load of pollutants in Seung-Gi stream was considered to influence negatively the sea water quality of Incheon. Solution plans to solve problems are as follows. First, circulation of treated water at Seung-Gi WWTP(Wastewater Treatment Plant) and retreated water by URC(ultra rapid coagulation) process treat with that. Second, sewage and wastewater is gathered, make it disposed. After then, we circulate treated water. If solution plans be applied, we can predict water quality. Then we could grope for how make to recovery role of Seung-Gi stream as stream.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.3
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• pp.367-372
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• 2008

This study configured the conventional $A^2O$ (Anaerobic-Anoxic-Aerobic bioreactor) system which the fixed media immersed into the anoxic reactor(Named PFR system : Plug Flow Reactor) for evaluating the removal efficiency of nitrogen in the wastewater. The experimental equipment was a cylinder which was consist of 4 pleated PE Pipes(Length 330M, Diameter 100mm) including 2 rope shape media. As a result, the average effluent T-N removal efficiency of the conventional $A^2O$ system was 17.9, 40.3, 50.6, 44.6% in each mode, but the average effluent T-N removal efficiency of the PFR system could achieve 38.8, 57.1, 71.8, 65.4% in each mode. It indicated that the PFR system caused to the increasing of C/N ratio that effected to the increasing of the denitrification efficiency. Not only the effective T-N removal efficiency but also the controllable install space will give advantages for retrofitting of the wastewater treatment plant with the conventional treatment system to the PFR system.

• Journal of Korean Society on Water Environment
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• v.32 no.5
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• pp.465-474
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• 2016

Since Gyungan stream is included in the protected zone of the water supply source of the Metropolitan area in Korea, the water quality needs to be continuously managed. Therefore, a measure is required that can inhibit the flow of water pollutant into the water body and facilitate the ecological restoration of riparian vegetation. A field survey was conducted on the hydrological characteristics of the landscape elements established on the downstream catchment of the Gyungan stream, the result of which showed that the paddy field and urbanized area can be regarded as point pollution sources. The upland field can be regarded as a non-point pollution source. In order to improve the water quality in the Paldang lake, we first recommended creating a riparian vegetation belt. We also suggested introducing a treatment wetland and an artificial plant island to places in which the creation of a riparian vegetation belt is not ensured. We recommend creating a treatment wetland equipped with diverse functional groups. For creating the plant island, we recommend Zizania latifolia and Typha orientalis, which showed the highest productivity among aquatic plants. The former could be introduced around the outlet of a paddy field and the estuary of tributaries, while the latter could be introduced to a water body directly sourced from mountainous land.

• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.727-736
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• 2001

Dentinal hypersensitivity is one of the complicated symptom rather than a disease. It has special reaction or pain over uncovered root by heat, mechanical or chemical stimulations, which are normal with healthy teeth, The purpose of this study is to discover rather MS Coat (oxalate-containing pre-polymerized resin suspension) or Elmex gel(amine fluoride+sodium fluoride) is effective on hypersensitivity after periodontal treatment using NRS(Numerica1 Rating Scales), which it is useful for evaluating pain level. This study has been prepared in Dankook Dental Hospital with generally healthy adult who had been suffered from dentinal hypersensitivity after periodontal treatment. Divided in three groups with saline(control group), MS Coat(test 1 group) and Elmex gel(test 2 group). And then, following evaluations were made at the end of 1 minute, 1 week, 1 month and 3 months. 1. The sequence of higher frequency & severeness of hypersensitivity is water within $7^{\circ}C$, air stream & explorer. 2. As time goes on, 1 minute, 1 week, 1 month & 3 months, severeness of hypersensitivity scored lower with water, air stream and explorer. 3. With explorer, the differences among three groups as time had to seen. 4. With air stream, the sensitivity scored lower after 1min with MS Coat, Elmex, and saline sequence. As time goes on the sensitivity was lower with MS Coat and Elmex than saline, but there was no difference between MS Coat and Elmex. 5. With water in $7^{\circ}C$, the sensitivity was much decreasing with MS Coat and Elmex than saline, but there was no difference between MS Coat and Elmex. As the result, MS Coat and Elmex are effective on hypersensitivity caused by periodontal treatment.

• Korean Journal of Ecology and Environment
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• v.55 no.2
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• pp.111-119
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• 2022

The occurrence of cyanobacterial blooming and the contaminant sources were analyzed in the downstream of Jecheon Stream, a tributary of Chungju Reservoir. The concentrations of chlorophyll a at the Myungseo Fishing Point (GPS; 37°03'25.5"N, 128°03'13.6"E) were 399.2 and 184.8 mg m^-3 on October 18, 2015 and September 25, 2016, respectively, and the concentrations of total microcystins, a cyanobacterial toxin mainly produced by Microcystis, were 124.09 and 79.71 ㎍ L^-1, respectively. The occurrence of cyanobacterial blooming at the downstream of Jecheon Stream was closely related to the water level of Chungju Reservoir. The cyanobacterial blooming occurred after the increase of water level in Chungju Reservoir, when the water body stagnated. As a result of analyzing National Water Quality Monitoring Data of the upper region of Jecheon Stream, the main source of pollutant was Jangpyeong Stream, the tributary of Jecheon Stream, and the discharge water from Jecheon Wastewater Treatment Plant located in Jangpyeong Stream was considered to be the most important source of contaminant.

• Economic and Environmental Geology
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• v.28 no.5
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• pp.455-467
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• 1995

In order to investigate the dispersion patterns and speciations of Cu, Pb, Zn and Cd in soils, stream sediments and stream waters, geochemical studies of soil, stream sediment and stream water samples collected in the vicinity of the Shi-Heung Cu-Pb-Zn mine was carried out Cation exchange capacity measurement, size analysis, X-ray diffraction analysis and batch test were performed to select applicable soil for adsorption treatment The average content of Cu, Pb, Zn and Cd in soils collected from tailings and ore dressing plant is 1084 ppm, 2292 ppm, 3512 ppm and 29.2 ppm, respectively, and therefore, tailings and ore dressing plant site may be the major contamination sources in this study area. The mean content of Cu, Pb, Zn and Cd in stream sediments is extremely high up to 794 ppm, 1633 ppm, 2946 ppm and 25.2 ppm, respectively. Tailing particles and heavy metal ions are dispersed along the tributary system. Results from the sequential extraction analysis indicate; (1) most of Cu is bound to organic matters and sulphides, (2) fraction of Pb is mainly bound to Fe and Mn oxides. Most of Zn is largely bound to Fe and Mn oxides and residual fraction. Ion exchangeable fraction of Cd is relatively higher than those of Cu, Pb and Zn. Batch test on soils collected from the kaolinite and/or pyrophyllite mines and from the control areas was carried out to select an applicable soil samples for adsorption treatment The sample, S10, collected from the control area 2 (clay content 33.2%) shows the highest $K_d$ (distribution coefficient). Organic content in soils and several clay minerals shows relatively good correlation with $K_d$. It means that applicable soils for adsorption treatment of heavy metals show high organic and clay content.

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.233-238
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• 1997

WASP5 was applied to evaluate water quality of Bokha stream with 17km of its main stem located in Ichon-city, Kyunggi province in Korea. Boundaries of the stream for the WASP5 were the Jumi bridge, 10 major tributaries and one wastewater treatment system. The stream was divided into 37 segments with about 350m length. The flowrate of the 10 day's average of the stream was obtained from the hydrograph data and the discharge-stage rating curve. Simulated quality constituents included nitrogen, phosphorus, BOD and DO. Monthly records of water quality and loads in 1996 were used for the calibration of parameters of WASP5. Simulation showed high correlations between calculated and observed concentration with monthly runoff ratio in Bokha stream. At downstream boundary, Jumi bridge [Seg.36], similar correlations were appeared. However, simulated concentrations by using annual runoff ratio were somewhat differentiated from those of the observed.