• 분석과학
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• 제8권4호
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• pp.1079-1087
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• 1995

The quality of human life is directly related to the quality of the environment. To assess environmental quality we must first determine the MCLG(Maximum Contaminant Level Goal), MCL(Maximum Contaminant Level), environmental impact and so on. The MCLG is the concentration at which no known adverse health effects occur. The MCLG is determined by risk assessment identifying which process is hazardous assessing, dose-response, human exposure, and characteristics of risk. With consideration of analytical methods, treatment technology, cost and regulatory impact, the MCL is set as close to the MCLG as possible. In this way, determination of the concentration and national distribution of contaminants is important for assessment of environmental quality The analytical sciences pose potential problems in assessing environmental quality. Continuing improvement in the performance of analytical instruments and operating technique has been lowering the limits of detectability. Contaminant concentration below the detection limit has usually been reported as ND(Not-Detected) and this has often been misunderstood as equivalent to zero. Because of this, more the contaminant concentration in the past was below the detection limit, whereas contaminants can be quantified now even though the contaminant concentration might remain the same or may even have decreased. In addition, environmental sampling has various components due to heterogeneous matrices. These samples are used to overestimate the concentration of the contaminant due to large variability, resulting in excess readings for MCL. In this paper, the significance of the analytical sciences is emphasized in both a conceptual and a technical approach to environmental assessment.

• Fibers and Polymers
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• 제7권1호
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• pp.73-78
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• 2006

The ability to absorb liquid and the dust removal performance are important factors for wiping cloths used to remove contaminants. We have developed a method that can determine the contaminant removal performance of wiping cloths. In the gravimetric method, experimental errors are unavoidable because the contaminant plate is much heavier than the contaminant material. However, we used image analysis to reduce the experimental errors, and did not use the heavy contaminant plate. The correlation coefficient between the image. analysis and the gravimetric methods was very high, at R=0.97, with a significance level of 95%. From the correlation analysis and empirical data, the image analysis method is a useful tool for measuring wiping efficiency. The wiping efficiency measured using image analysis has a close relationship to the wiping speed, viscosity of the contaminant, and wiping pressure, at the significance level of 95%.

• Environmental Engineering Research
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• 제13권2호
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• pp.73-78
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• 2008

For a given soil-contaminated site, a level of soil contamination is characterized and decisions on risk may be made from the risk assessment. The study evaluated critical design factors for the determination of sample size in the sampling design plan and the assessment of soil contaminant- leaching to groundwater. Two variables, the minimum relative detectable difference (T) and coefficient of variation (CV) were evaluated for the sample size determination. The minimum number of samples can be appropriately determined by CV under a T value greater than or equal to 0.2. Soil-contaminant leaching to groundwater was evaluated by using the Soil Screening Level equation of U.S. Environmental Protection Agency and the Risk Based Screening Level equation of American Society for Testing and Materials, with the same input parameters. The groundwater concentrations estimated from soil contaminant concentrations were significantly affected by the Darcy velocity of groundwater and the organic content of soil.

• 대한토목학회논문집
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• 제39권6호
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• pp.751-758
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• 2019

본 연구는 오염부지의 위해성 평가를 위해 수치모의 기반 오염물질의 노출이동경로 평가에 활용가능한 개념모델을 제시하였다. 이를 위하여 1차원으로 유한차분 기법을 적용하여 지하수 내 오염물질 이송확산을 모의하였다. 불포화대 경로에서의 수리지질학적 및 오염물질 매개변수가 가질 수 있는 범위를 설정하여 범용 시나리오 및 오염물질별 시나리오를 구성하여 모의에 적용하였다. 모델에서는 흡착 및 생분해를 갖는 유한차분 1 차원 이송확산이 고려되었고, 또한 초기 농도가 시간이 지남에 따라 고갈되는 것을 가정하였다. 일반 시나리오의 결과는 지하수 침투율이 감소함에 따라, 오염원에서 지하수면까지의 경로가 길어질수록 지하수면으로 유입되는 지점의 농도 범위는 낮아졌다. 특히, 높은 생분해 속도와 오염원의 빠른 고갈의 경우, 범용 시나리오가 좁은 범위의 지하수 유입농도 예측치를 보여주었다.

• Ocean Science Journal
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• 제40권1호
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• pp.1-10
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• 2005

Variations in species diversity and abundance of polychaete taxocenes that occurred in 1980-1989 under different contamination levels of bottom sediments were studied in three areas of Peter the Great Bay. The most polluted area was shown to be the Golden Horn Inlet where contaminant contents in the bottom sediments exceed the threshold values of negative biota alterations. Amursky Bay is characterized by a moderate level of contamination, while Ussuriysky Bay has the lowest level of contamination. Pollutant contents vary considerably within the same areas and their separate patches are polluted differently. An integral index characterizing the contamination of bottom sediments is proposed. This index is an average grade of the rank value of contaminant contents in sediments. The index was used to compare the contamination level and data on polychaete species diversity and abundance. The highest species diversity of polychaetes is found in the least affected zones. Monotonous decrease of the species number, as well as decrease in the indices of diversity and evenness, is correlated with pollution level increases. Significant growth of the average polychaete biomass and polychaete density is observed in the case of an increase of contamination from low to moderate levels. Conversely, the biomass and abundance of polychaetes decline following an increase in contamination.

• 환경정책연구
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• 제5권2호
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• pp.49-67
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• 2006

선진 외국에서 먹는물 중 방사성물질의 관리동향에 대한 고찰은 다음과 같다. 미국은 1974년 안전한 음용수법에 규제안을 설정한 후, 30년 이상 개정하여 현재 우라늄 MCL은 $30{\mu}g/L$, 라돈 AMCL 4,000pCi/L 또는 MCL 300pCi/L, 라듐-226과 라듐-228의 합 5pCi/L로 설정하여 관리하고 있다. 캐나다는 우라늄을 $20{\mu}g/L$로 잠정적으로 설정하였다. WHO는 2004년 9월 우라늄과 라돈의 가이드라인을 각각 $15{\mu}g/L$과 100Bq/L로 개정 하였다. 선진 외국은 먹는물 중 방사성물질에 대하여 수십년간 연구조사결과를 토대로 수질기준을 정하였고, 지속적으로 개선 및 보완을 하여 관리하고 있음을 알 수 있었다.

• 한국환경농학회지
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• 제33권4호
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• pp.239-244
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• 2014

BACKGROUND: Heavy metals contamination of soils in the vicinity of abandoned mines in South Korea has been investigated. However, PAHs contamination rarely has been studied. Both heavy metals and PAHs concentrations have been measured in this study. METHODS AND RESULTS: The samples of soil and sediment were collected from the vicinities of three abandoned coal mines and two abandoned metal mines for analysis of heavy metals contaminants and PAHs concentration from April to September 2012. After preparation of these samples following the Korean standard test method for soils, the concentrations of heavy metals contaminants and PAHs were measured using ICP-OES and GC-MS, respectively. It was observed that the concentration of Arsenic was above the concern level based on 'area 1' suggested by Korean soil conservation law, resulting that Arsenic is the main contaminant in these areas. Also Cd, Cu, Pb and Zn were observed as a partial contaminants. The concentrations of other investigated components including benzo(a)pyrene were less than the concern level. CONCLUSION: The correlation observed between Arsenic (as main contaminant) and PAHs concentrations suggested that the contaminant source and pathway are different for each other. The effect of mine activity on PAHs concentration was rarely observed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.373-381
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• 2005

The permeability of contaminated soil and elapsed time are important considering factors to in-situ soil remadiation. Gabr et. al. (1996) derived the solution equation of contaminant concentration ratio as initial one (C/$C_0$) with time and spatial changes in contaminated area which embedded with vertical drains. The contaminant concentration ratio (C/$C_0$) is analyzed with time and spatial changes in three different permeability areas which are $k=l.0{\times}10^{-5,}$ $l.0{\times}l0^{-6,}$ $l.0{\times}l0^{-7}\;_{m/s}$ by using the Gabr's equation. Results from numerical analysis indicate that the ratio (C/$C_0$) decreases as the elapsed time increases in every point, however, remediation efficiency decreases as the analyzing point is far from injection well to extraction one and is deeper from top level of contaminated area. And also it decreases as the permeability of contaminated area decreases. Especially, the lower permeability of contaminated area effects directly on the soil remediation, in this research, under condition which the permeability of contaminated area is $l.0{\times}l0^{-7}\;_{m/s}$, the maximum time needed to attain 90% clean up level ($t_{90}$) is 65,690 hours(7.5 years), it takes so much time to clean the low permeability contaminated soil.

• 대한지하수환경학회지
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• 제1권1호
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• pp.1-5
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• 1994

난지도 매립장 하부지반을 통한 오염이동 특성을 2차원 유한 요소 오염이동 모델을 이용하여 알아보고 부분적인 차폐벽을 매립장 주위에 설치하였을 경우 초래되는 매립장내 침출수 누적 효과를 유한 차분 지하수흐름 모델을 이용하여 분석하였다. 분석에 사용된 입력계수는 현장에서 측정된 오염농도 자료를 이용 검증한 후 향후 30년 동안에 한강변으로 누출될 수 있는 오염농도 변화를 분석하고 매립장내 침출 수두와 확산계수의 증가가 오염물 이동에 미치는 민감도를 알아보았다. 오염이동 해석 결과 한강주변의 난지도 매립장 침출수로 인한 염소이온농도 최대값은 1488 mg/l로서 매립장 패쇄후 17년만에 이루어지는 것으로 나타났다. 매립장내 침출수위와 확산계수의 변화는 모두 침출수 이동을 촉진하나 침출수위면이 증가 할수록 침출수 농도 증가 폭은 커져가는 반면 확산계수 증가에 대한 침출수 농도 증가 폭은 작아져서 일정 농도로 수렴하는 경향을 보였다.

• 한국지반공학회논문집
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• 제22권9호
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• pp.5-14
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• 2006

본 논문에서는 유기물질로 오염된 퇴적토에서 동전기 침전 및 정화 기법을 이용하여 초연약한 퇴적토의 침하를 촉진시켜 밀도를 증진시키는 연구를 수행하였다. 본 논문에서는 인체에 무해한 에틸렌글리콜 유기물질을 일반수와 적정하게 섞은 오염수에 카오리나이트 점토를 혼합하여 함수비가 높은 슬러리 상태를 조성하여 만든 오염된 퇴적토를 시료로 사용하였다. 일반적으로 동전기기법을 이용한 전기영동 및 전기삼투에 의하여 슬러리내의 고형물 입자를 음극으로 이동시키고 간극수를 양극으로 배제시킬 수 있는 것으로 보고되고 있다. 본 연구에서는 오염된 퇴적토에 대하여 고형물함량, 공급전압 및 오염농도를 변화시키면서 동전기침전 및 동전기정화 시험을 연속적으로 동시에 수행하였으며 동전기침전 및 동전기정화 공정에서 발생한 시료의 침하 및 밀도 변화에 대하여 살펴보았다. 시험결과 오염퇴적토의 침하량은 공급전압이 클수록 고형물함량 및 오염농도가 작을수록 증가하는 것으로 나타났다. 그리고 오염퇴적토의 밀도는 동전기 침전단계에서는 시료의 침하에 의하여 증가하고 동전기 정화단계에서는 물보다 무거운 유기물질의 유출에 의하여 감소하는 것으로 나타났다.