• Nuclear Engineering and Technology
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• 제50권8호
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• pp.1355-1363
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• 2018

Many radionuclides exist in normal environment and artificial radionuclides also can be detected. The radionuclides ($^{131}I$) are widely used for labeling compounds and radiation therapy. In Korea, the radionuclide ($^{131}I$) is produced at the Radioisotope Production Facility (RIPF) at the Korea Atomic Energy Research Institute in Daejeon. The residents around the RIPF assume that $^{131}I$ detected in environmental samples is produced from RIPF. To ensure the safety of the residents, the radioactive concentration of $^{131}I$ near the RIPF was investigated by monitoring environmental samples along the Gap River. The selected geographical places are near the nuclear installation, another possible location for $^{131}I$ detection, and downstream of the Gap River. The first selected places are the "front gate of KAERI", and the "Donghwa bridge". The second selected place is the sewage treatment plant. Therefore, the Wonchon bridge is selected for the upstream of the plant and the sewage treatment plant is selected for the downstream of the plant. The last selected places are the downstream where the two paths converged, which is Yongshin bridge (in front of the cogeneration plant). In these places, environmental samples, including sediment, fish, surface water, and aquatic plants, were collected. In this study, the radioactive iodine ($^{131}I$) detection along the Gap River will be investigated.

• 한국물환경학회지
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• 제33권3호
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• pp.282-290
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• 2017

A long-term resuspension of small particles, called persistent turbidity, is one of the most important water quality concerns in the dam reservoirs system located in North Han River. Persistent turbidity may incur aesthetic nuisance and harmful effect on the ecosystem health, in addition to elevated water treatment costs for the drinking water supply to the Seoul metropolitan area. These sufferings have been more intensified as the strength and frequency of rainfall events increase by climate change in the basin. This study was to analyze the effect of an extreme turbidity flow event that occurred in 2006 on the serial reservoirs system (Soyang-Uiam-Cheongpyung-Paldang) in North Han River. The CE-QUAL-W2 model was set up and calibrated for the river and reservoirs system using the field data obtained in 2006 and 2007. The results showed that Soyang Reservoir released turbid water, which was classified as the TSS concentration is greater than 25 mg/L, for 334 days with peak TSS of 264.1 mg/L after the extreme flood event (592.7 mm) occurred between July 10 and 18 of 2006. The turbid water departed from Soyang Reservoir reached at the most downstream Paldang Reservoir after about 20 days and sustained for 41 days, which was validated with water treatment plant data. Since the released water from Soyang Reservoir had low water temperature and high TSS, an underflow formed in the downstream reservoirs and vertically mixed at Paldang Reservoir due to dilution by the sufficient inflow from South Han River.

• 상하수도학회지
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• 제11권2호
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• pp.94-104
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• 1997

Ozone Treatment is getting a common process in a water treatment plant all over the nation. Especially an advanced water treatment using ozone and biofiltration has been a typical method in the regions where using the Nak-Dong River as a drinking water source. The effectiveness of ozone treatment in a continuous flow contact system was investigated with sand filtered water of the Nak-dong River. Pilot tests of the experiments were performed three times of the year like June, August, and October 1995. Most degradable organics of sand filtered water were oxidized in the first and second contact chamber of the system. Ozone treatment was effective for the removal of UV254 absorbance. However, Noticeable removals of $KMnO_4$ demand and TOC(Total Organic Carbon) were occurred when their concentrations exceeded about 5mg/l. The organics causing $KMnO_4$ demand and TOC were degraded into lower molecular matter in an early stage of the ozone contact in the system. Dissolved oxygen concentration was increased after ozone treatment.

• 한국습지학회지
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• 제19권4호
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• pp.409-422
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• 2017

월동수조류의 군집에 영향을 미치는 환경요인을 파악하기 위하여 원주천을 6구간으로 나누어 조류의 군집 및 하천의 크기, 기온, 수질, 저서성무척추동물, 어류를 조사하였다. 원주천에서 수조류의 군집에 영향을 미치는 요인은 하천의 구조 및 기온, 수질이었다. 하천의 구조 중 월동수조류의 군집에 가장 큰 영향을 미치는 요인은 저수로의 폭과 흐르는 물의 넓이인 유폭으로 그 넓이가 넓을수록 월동수조류의 종수와 개체수가 많았으며, 둔치의 폭이 넓어서 저수로의 폭과 유폭이 좁아질수록 개체수는 적었다. 월동기의 기온 변화는 하천의 결빙으로 이어지므로 수조류의 군집에 영향을 미쳤으며 결빙되지 않는 구간은 기온의 하강과 상승에 뚜렷한 증가와 감소를 보였다. 수질조사 항목 중 pH, 수온, COD, BOD, T-N, T-P, 총대장균의 수치는 하류로 갈수록 증가하여 월동수조류의 개체수 증가와 높은 상관성을 보였는데 하류에 위치한 하수처리장의 영향으로 S6의 수질검사 항목의 수치가 높게 나타났으며 월동수조류의 개체수 또한 가장 많이 관찰되었다. 하수처리장 배출수는 수질에 상당한 영향을 미치는 것으로 보이는데 T-N을 비롯하여 여러 항목 수치의 증가는 하천의 영양화를 촉진시키고 이로 인해 유기물질의 축적과 수서생물의 증식을 가져옴으로 이를 먹이원으로 하는 월동수조류의 증가 원인이 될 수 있을 것으로도 여겨진다. 저서성 대형무척추동물의 군집과 어류의 군집은 원주천 모든 구간에서 대체적으로 양호한 것으로 나타났으나 월동수조류의 군집과의 상관성을 보이지 않았다.

• Environmental Engineering Research
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• 제23권2호
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• pp.136-142
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• 2018

The river water source of Saidabad Surface Water Treatment Plant at Dhaka, Bangladesh, is deteriorated too much to be treated by conventional treatment process due to excessive ammonia pollution. In order to improve the raw water quality before it enters into the main treatment chain, a pilot study was conducted for pre-treatment of the raw water. The objective is to investigate the rate of reduction of ammonia using the Meteor pilot, a biological pretreatment system, which is a laboratory scale Moving Bed Biofilm Reactor with a nominal volume of hundred liters, filled with 50 L of Meteor 660 media. The reduction of ammonia was quite significant on average 73%, while the reduction of COD was in a range from 20 to 60%. The Meteor pilot was able to treat and nitrify the raw water and produce an effluent that respects the guarantee of ammonia < $4.0mg\;NH_3-N/L$ when the raw water ammonia concentration was < $15mg\;NH_3-N/L$. The study identified operating parameters necessary to achieve the desired goal of adequate ammonia removal. The study results would benefit a range of systems across the country by providing guidance on the design and operation of a biological pre-treatment system for ammonia removal.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.183-186
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• 2008

All measures to cope with flooding rely on flood predictions to some extent, and the effectiveness of these measures is dependent on the quality of flood predictions. It is important to track properly the movements of the river-bankline in numerical modeling because the location of it varies continuously in the flood inundation. In this study, the wet and dry treatment is used to describe the moving river-bankline accurately (Cho, 1996). An oscillatory flow motion in a parabolic basin is used to validate the performance of the developed model based on quadtree grids. As a result of a simulation, a reasonable agreement is observed with analytical and Cho's results.

• 대한환경공학회지
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• 제27권12호
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• pp.1332-1339
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• 2005

본 연구의 목적은 310종 다성분 동시분석법을 이용하여 영산강유역 생활하수처리장 방류수에서 유기오염물질의 분포특성을 연구하는 것이다. 그 결과, 5개 시료채취지점에서 많은 유기오염물질이 검출되었고 그 중 농약류, CH구조의 벤젠류와 다환방향족화합물 그리고 CHO구조의 페놀류와 프탈레이트류 화합물이 주요오염물질로서 검출되었다. 특히, 14종의 농약류가 주로 여름철에 방류수에서 검출되었다. 1-Chlorobenzen과 p-octylphenol은 각각 $0.52{\sim}0.61\;{\mu}g/L$과 $0.04{\sim}0.89\;{\mu}g/L$ 농도범위를 가지고 빈번히 검출되는 오염물질이다. 또한, 5개 시료채취지점에서 diethylphthalate를 포함한 18종의 내분비계교란물질이 관찰되었다. 따라서 이러한 연구결과로부터 우리는 영산강유역 생활하수처리장 방류수에서 농약류와 CH, CHO구조를 가진 화학물질들에 대해 특별 관리가 이루어져야 한다고 생각한다.

• 한국물환경학회지
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• 제33권5호
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• pp.580-586
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• 2017

The fractionation characteristics of organic matter were investigated in inflow and effluent of each other pollution sources and river. While the DOC/TOC ratio in the influent of public sewage treatment plant and livestock disposal facilities was above 0.58, the POC/TOC ratio of human livestock Night soil treatment plant and stormwater runoff was more than 0.7. The TOC removal efficiency of public sewage treatment plant and human livestock Night soil treatment plant were 88.5 % and 99.6 %, respectively. Although the concentration distribution of organic matter pollution most of total organic carbon (TOC) in effluent of pollution sources accounted for dissolved organic carbon (DOC) type (DOC/TOC ratio >0.89) and Refractory-DOC (RDOC)/TOC ratio was higher (>0.65). The fractionation characteristics of organic matter in river were similar with that of sewage treatment plant and TOC concentration showed the positive correlation with DOC ($r^2=0.93$) and RDOC ($r^2=0.89$) concentration. The decay rate of Labile DOC (LDOC) (avg. $0.128day^{-1}$) was higher than labile particulate organic carbon (LPOC) ($0.082day^{-1}$), while that of DOC ($0.008day^{-1}$) was lower than POC ($0.039day^{-1}$) (paired t-test, p < 0.001, n = 5). These study results suggested that it should consider important both TOC and DOC as the target indicator to control refractory organic matter in pollution sources.

• 환경위생공학
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• 제7권2호
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• pp.29-36
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• 1992

Among the rivers in Korea, the Han River is the largest, most important one, which runs through the Seoul metropolitan region in the west toward the yellow sea. In the Han River basin there live as many as 17.1 mil. people including appr, 11 mil, citizens in Seoul. The Seoul Metropolitan region, already containing appr. 40% of the nation's total populating, expectedly poses an ever-growing polluting burden to the Han River. Due to Korea's vigorous industrialization and heavy urbanization in the past quarter century, water pollution was observed to be increasing in the Han River until the mid-1980's, but thereafter the Han River began to improve little by little by virtue of the government's massive investment and all-out efforts in water preservation. Public awareness on the importance of environmental protection is increasing unprecedentedly. With a view to meeting people's growing demand for clean water and pleasant environment, the government established the "Comprehensive Mid-Term Environmental Conservation Plan" (1992∼1993) in 1991. According to the plan, 1,315 bil.won(1.7 bil.us$ ) is to be poured into the Han River Basin to install 113 water pollutant abatement plants including 43 treatment facilities. To successfully cope with the future's challenging need for the environmentally sound sustainable development, a variety of measures and an array of policies are going to be incorporated with emphasis on, -redistributing such polluting sources as population and industries -tightening control of the water pollutant discharge -restricting the pollution-accompanying land use -enhancing the assimilation capacity of the river -stirring up the public awareness and participation in the environment protection We hopefully anticipate that with those e(forts the Han River will improve as drawn in the attached "1996's Envisioned Han River Quality".

• 한국환경과학회지
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• 제22권12호
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• pp.1615-1624
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• 2013

The aims of this study were to investigate and confirm the occurrence and distribution patterns of blood lipid lower agents (BLLAs) in Nakdong river basin (mainstream and its tributaries). 4 (atorvastatin, lovastatin, mevastatin and simvastatin) out of 5 statins and 2 (clofibric acid and zemfibrozil) out of 3 fibrates were detected in 29 sampling sites and simvastatin (>50%) was predominant compound followed by atorvastatin, lovastatin and clofibric acid. The total concentration levels of BLLAs on April, August and November 2009 in surface water samples ranged from ND~25.7 ng/L, ND~18.8 and ND to 38.8 ng/L, respectively. The highest concentration level of BLLAs in the mainstream and tributaries in Nakdong river were Goryeong and Jincheon-cheon, respectively. The sewage treatment plants (STPs) along the river affect the BLLAs levels in river and the BLLAs levels decreased with downstream because of dilution effects.