• 한국진공학회:학술대회논문집
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• 한국진공학회 2008년도 제35회 하계학술대회 초록집
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• pp.195-195
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• 2008

• Water Engineering Research
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• 제7권1호
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• pp.1-8
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• 2006

Recently, the population growth and agricultural development are rapidly undergoing in the South-West Texas. The junction of three river basins such as Lavaca river basin, Colorado-Lavaca Coastal basin and Lavaca-Guadalupe Coastal basin, are interesting for non-point and point source pollutant modeling: Especially, the 2 basins are an intensively agricultural region (Colorado-Lavaca Coastal/Lavaca-Guadalupe Coastal basins) and several cities are rapidly extended. In case of the Lavaca river basin, there are many range land. Several habitat types wide-spread over three relatively larger basins and five wastewater discharge regions are located in there. There are different hazardous substances which have been released. Total nutrient loads are composed of land surface load and river load as Non-point source and discharge from wastewater facilities as point source. In 3 basins region, where point and non-point sources of poll Jtion may be a big concern, because increasing fertilizers and pesticides use and population cause. This project objective seeks to how to assess and control the accumulation of non-point and point source and discuss the main impacts of agriculture and environmental concern as non-point source with water quality related to pesticides, fertilizer, and nutrients and as point source with wasterwater discharge from cities. The GIS technique has been developed to aid in the point and non-point source analysis of impacts to natural resource within watershed. This project shows the losses in $kg/km^2/year$ of BOD (Biological Oxygen Demand), TN (Total Nitrogen) and TP (Total Phosphorus) in the runoff from the surface of 3 basins. In the next paper, sediment contamination will show how to evaluate in Estuarine habitats of these downstream.

• 대한환경공학회지
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• 제33권12호
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• pp.861-867
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• 2011

새만금호로 유입되는 만경강과 동진강의 하상 퇴적물의 오염도를 파악하기 위하여, 퇴적물 중 강열감량, COD, 총질소, 총인 및 중금속(As, Cd, Cr, Pb, Zn)의 농도를 분석하였다. 강열감량, COD, 총인의 농도는 각각 평균 2.40 (${\pm}2.18$)%, 2.97 (${\pm}3.06$)mg/g sediment, 0.370 (${\pm}0.351$) mg/g sediment이었으며, 이들 물질에 의한 퇴적물의 오염도가 높지 않았다. 하지만 2008년에 비해 2009년의 시료에서 농도가 증가하였으며, 이러한 결과는 퇴적물의 오염이 점진적으로 진행되고 있음을 의미한다. 총질소의 경우에는 0.59~13.11 mg/g sediment로 채취 지점 및 채취 시기에 따라 변이가 컸으며, 국내 하천 및 호소의 퇴적물 준설 기준과 비교할 때, 질소 오염이 심한 것으로 나타났다. 이러한 결과는 새만금호의 수질을 유지하기 위하여 만경강과 동진강의 질소오염의 원인을 파악하고 대책의 수립이 필요함을 의미한다. 중금속의 경우에는 크롬을 제외하고 토양오염우려기준을 초과하지 않아 오염이 일어나지 않은 것으로 판단된다. 크롬의 경우, 만경강 상류의 일부 지역에서 우려기준을 초과하는 높은 농도가 측정되어, 이에 대한 원인 분석과 대책 수립이 필요한 것으로 판단된다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.254-257
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• 2002

The purposes of this research are to identify the source and to analyze the pathway of nitrate contamination in "cultural village", Jeungpyeong. In order to examine recharge processes and flow pattern that closely related to the influent of nitrate contaminant, the flow field was simulated and the oxygen and hydrogen stable isotopes were analyzed. The nitrogen isotope was used to delineate contaminant sources. The shallow groundwater was mainly composed of precipitation, but leakage of domestic water and sewage contributed to the recharge. Nitrate contaminants were possibly from the leakage of sewage and animal waste. The nitrate concentration decreased due to dilution by low concentration water.ion water.

• 환경위생공학
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• 제10권2호
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• pp.59-66
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• 1995

According to the population increase and industrialization, the drinking water source, Han River and other sources, are contaminated by industrial wastewater, domestic sewage, and agricultural discharges. Among the contaminants, and toxic substances, pesticides is most interesting items (or human health Our drinking water has some problems of THMs, Fe, odor, etc., $o many people use groundwater or bottled water. But sometimes there are many reports about groundwater contamination owing to the agricultural chemicals, waste disposal, industrial wastewater. In America, there are about 45,000 groundwave supply company and in korea about 20% of total population are using groundwave as drinking water source. In America, studies about SEE is increasing Instead of liquid- liquid extraction method, because of many advantages of SEE methods. Author tried to investigate SPE methods in the spiked water samples to compare with liquid- liquid extraction method and got the following results. The amount of organic solvents which are used In SPE method is less than 1/10 compared with liquid- liquid method, the analytical duration time is shortened, and the ethyl acetate was good fluent among several organic solvents.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2007년도 학술발표회 논문집
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• pp.909-910
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• 2007

The volatile organic compounds exposure is governed by the source distance and dispersion of the pollutant into air and groundwater. The purpose of this study was to validate suggested models for the prediction of concentration distributions. The study design was organized into different methods to simulate industry site. The distribution models generally showed a fair agreement with measured data. For graphical representation of concentration of volatile hydrocarbon, it has to obtain a continuous representation of the contamination of the site. Therefore, the used interpolative methods examined for this project are the IDW(inverse Distance Weighting) and kriging method. In the results, in summary, all two different methods can be used to quantify exposures at a particular source area, and thus provide, a solid foundation for making risk-based decisions. All the calculations can be performed using Excel's built-in functions, and the capabilities of geospatial analysis allow the results to be displayed visually. However, anyone who uses these methods should understand all of the assumptions and limitation.

• 정보처리학회논문지D
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• 제11D권1호
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• pp.31-38
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• 2004

본 논문은 지하수 관정의 안전성 평가를 위한 시스템을 구현하였다. 지하수의 수질은 지상오염 원인의 영향을 받으므로 수질 성분의 측정으로 영향의 원인과 그 정도를 파악할 수 있다. 본 논문은 지하수 관정과 영향을 주는 지리-객체의 공간관계성을 지리정보시스템의 포함(contain) 연산자와 거리(distance) 연산자를 사용하여 평가하는 방법을 제안하였다. 연구대상은 전라북도 군산 지역으로서 주로 제4기 충적층에 있는 75개의 지하수 관정의 성분 측정값을 제안한 방법으로 비교 평가한 결과를 ZEUS 2000 지리정보시스템에 저장, 표현할 수 있게 하고 ZEUS/SQLX, ZEUS/COM 그리고 Visual Basic 6.0 프로그래밍 언어를 이용하여 검색, 연구 분석 할 수 있는 사용자 인터페이스를 구현하였다. 연구의 결과 지하수 관정과 다른 지리-객체들의 공간관계성을 확인하였고 지리정보시스템을 이용한 효과적인 안정성 평가지수를 개발하였다. 더욱 많은 지역의 사례에 대한 비교 평가로 제안한 평가 모델을 검증하는 것을 향후 연구과제로 남긴다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.215-218
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• 2002

전형적인 농촌지역 지하수의 질산성 질소 오염현상에 대하여 오염원 규명, 지하수 오염범위와 오염도 파악을 위하여 이 연구를 수행하였다. 연구지역은 대규모 축사가 곳곳에 위치한 축산단지 인근지역이며, 벼농사와 포도재배가 이루어지고 있다. 이 지역의 수리화학적 특성을 밝히기 위하여 지하수파 지표수 시료를 채취하여 화학분석을 수행한 결과, 1차 17지점, 2차 22지점에서 채취한 지하수 시료 중 32~42%에서 질산성 질소 성분이 음용수질 기준(10 mg/L)을 ,초과하였으며, 77%에 해당하는 지점이 인위적 오염물질의 유입가능성이 있는 것(3 mg/L 초과)으로 나타났다. 질소 동위원소($\delta$$^{15}$ N-NO$_3$) 분석 결과에 의하면, 질산성 질소 성분은 대부분 축산폐수 기원임이 밝혀졌다. 현재 축사가 운영되고 있는 지역 뿐 만이 아니라 폐축사가 위치한 지역에서도 질산성 질소 오염이 나타나 축사가 천부지하수질에 오랜 기간동안 영향을 미칠 수 있음이 밝혀졌다.

• 한국물환경학회지
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• 제22권2호
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• pp.271-276
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• 2006

The outbreak cases of Cryptosporidium or Giardia from drinking water in abroad have drawn attentions on the public health. It is well known that Cryptosporidium is the most resistant organism against chlorine disinfection. To guesstimate the levels of Cryptosporidium and Giardia in Korean surface water, 1~2 samples from 22 drinking water sources in four Korean major rivers of Han, Keum, Nakdong, and Youngsan were monitored. In addition, two sites in Kyunganchon, a contaminated river were monitored for comparison. In source waters, detection rates of Cryptosporidium and Giardia were 15% (6/39) and 21% (5/24) with the range of 1~3 oocysts/10 L and 1~6 cysts/10 L, respectively. In Kyunganchon, they were 60% (6/10) and 70% (7/10) in the range of 1~9 oocysts/10 L and 10~72 cysts/10 L, respectively. When one of the source waters in Han river was monitored monthly, Cryptosporidium were found mostly in cold season. Matrix of the samples gave influence on the recoveries of the spiked protozoa. The recoveries of both Cryptosporidium and Giardia increased in the samples of Kyunganchon, known as contaminated area. However, protozoan recovery did not show significant relation with turbidity, the index of matrix contamination, which implies that there are additional unveiled features of matrix affecting the recoveries of the protozoa. The protozoan distribution in Kyunganchon showed significant relations with Cl. perfringens, anaerobic and spore forming indicator bacteria of fecal contamination by regression analysis, but not with turbidity, the general indicator of water quality.

• 한국의학물리학회지:의학물리
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• 제29권4호
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• pp.101-105
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• 2018

In this paper, a neutron moderation system for boron neutron capture therapy (BNCT) based on a $^{252}Cf$ neutron source is proposed. Different materials have been studied in order to produce a high percentage of epithermal neutrons. A moderator with a construction mixture of $AlF_3$ and Al, three reflectors of $Al_2O_3$, BeO, graphite, and seven filters (Bi, Cu, Fe, Pb, Ti, a two-layer filter of Ti+Bi, and a two-layer filter of Ti+Pb) is considered. The MCNPX simulation code has been used to calculate the neutron and gamma flux at the output window of the neutronic system. The results show that the epithermal neutron flux is relatively high for four filters: Ti+Pb, Ti+Bi, Bi, and Ti. However, a layer of Ti cannot reduce the contribution of ${\gamma}$-rays at the output window. Although the neutron spectra filtered by the Ti+Bi and Ti+Pb overlap, a large fraction of neutrons (74.95%) has epithermal energy when the Ti+Pb is used as a filter. However, the percentages of the fast and thermal neutrons are 25% and 0.5%, respectively. The Bi layer provides a relatively low epithermal neutron flux. Moreover, an assembly configuration of 30% $AlF_3+70%$ Al moderator/$Al_2O_3$ reflector/a two-layer filter of Ti+Pb reduces the fast neutron flux at the output port much more than other assembly combinations. In comparison with a recent model suggested by Ghassoun et al., the proposed neutron moderation system provides a higher epithermal flux with a relatively low contamination of gamma rays.