• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2001년도 정기총회 특별강연 및 춘계학술연구발표회(2)
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• pp.77-82
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• 2001

• 농촌계획
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• 제2권1호
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• pp.69-78
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• 1996

Environmental impact assessment survey reflecting farmers` opinion on the residence and production space in rural settlement area by ORD showed that more than 86% of respondents thought their reservoirs and waterways (small rivers) were getting seriously contaminated primarily by garbage and livestock manure. A typical rural settlement unit was taken to assess the impact of improper management of livestock manure in the farms on the water quality of small river flowing down along the villages where swine and dairy farms were situated in Daejook 2, 3-ri, Seolseong-myun, Icheon-gun. Nitrogen compounds such as NO$_3$-N, NO$_2$-N, NH$_3$-N, and phosphorus compound H$_x$PO$_4$, DO, BOD$_5$, COD, and microbial density were analyzed to evaluate water quality at five test sites designated along the water stream. Tests showed. for example, BOD$_5$ at site 4 was average 9.2mg/l which was about 3~8 times higher than that of observation site 2 and 3, at which most livestock houses were situated. This is a clear evidence that the nutrients of livestock manure illegally discharged to small river can lead to an eutrophication of the river at downstream. A soil absorption system with aeration could be one of alternatives to treat the contaminated wastewater by livestock manure. The place at downstream, inbetween observation site 1 and 2, could be the best construction site for the treatment facility from the standpoint of the overall treatment efficiency, An enclosed composting system can also be regarded as a good alternative for treatment of the sludge which is the by-product of the soil absorption system operation.

• 지질공학
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• 제5권3호
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• pp.259-276
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• 1995

난지도의 매립지 및 주변 침출수의 부존 양태를 파악하기 위하여 전기 비저항 수직 탐사와 수평 탄사가 수행되었다.매립지 내에서 수행된 전기 탐사 결과는 매립지 내에 기저 해발 고도 30m 지점을 전후로 하여 형성되어 있으며 이 기저 침출수 상부에도 상당량의 부유 침출수가 존재함을 보여준다. 매립지의 주변에서 획득된 전기 탐사 결과는 난지도의 침출수에 의해 오염된 지하수가 한강으로 유입되고 있음을 보여준다. 또한 이 지역의 기반암 상부도 이미 오염된 지하수에 크게 영향을 받는 것으로 판단된다. 난지도 매립지 및 주변 지역의, 침출수에 의해 포화된 지층은 전기 비저항치가 10 ohm-m 이하인 것으로 관측되었으며, 이러한 낮은 비저항치는 이 지역의 지하수 및 지층이 매우 심하게 오염되어있음을 지시한다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.52-57
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• 2004

해체부지 선량평가 모델의 주요 핵종에 대한 key parameter를 분석하기 위하여 민감도 분석을 수행하였다. 본 연구에서 민감도 분석을 수행하기 위한 주요 가정 사항으로서 피폭시나리오는 가장 보수적인 resident farmer를 그리고 방사성핵종의 오염 정도는 0.037 Bq/g로 하였다. 분석결과, 감마 방출 핵종인 Cs-137과 Co-60의 경우에는 오염지역의 면적과 거주관련 변수(외부감마차폐인자와 실내 거주시간분율), C-14 핵종의 경우에는 환경변수와 불포화층의 수문학적 변수가, Sr-90 핵종의 경우에는 오염지역의 토양 밀도가 선량에 미치는 영향이 큰 parameter로 확인되었다.

• Environmental Engineering Research
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• 제25권1호
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• pp.29-35
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• 2020

The aim of this study was to estimate the microbial metabolic activity of indigenous soil microbes under the radon exposure with different intensity and times in the secured laboratory radon chamber. For this purpose, the soil microbes were collected from radon-contaminated site located in the G county, Korea. Thereafter, their metabolic activity was determined after the radon exposure of varying radon concentrations of 185, 1,400 and 14,000 Bq/㎥. The average depth variable concentrations of soil radon in the radon-contaminated site were 707, 860 and 1,185 Bq/㎥ from 0, 15, and 30 cm in deep, respectively. Simultaneously, the soil microbial culture was mainly composed of Bacillus sp., Brevibacillus sp., Lysinibacillus sp., and Paenibacillus sp. From the radon exposure test, higher or lower radiation intensities compared to the threshold level attributed the metabolic activity of mixed microbial consortium to be reduced, whereas the moderate radiation intensity (i.e. threshold level) induced it to the pinnacle point. It was decided that radon radiation could instigate the microbial metabolic activity depending on the radon levels while they were exposed, which could consequently address that the certain extent of threshold concentration present in the ecosystem relevant to microbial diversity and population density to be more proliferated.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.131-134
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• 2005

Anaerobic reductive dechlorination of tetrachloroethylene(PCE) to ethylene was investigated by performing laboratory experiments using semi-continuous flow two-in-series soil columns. The columns were packed with soils obtained from TCE-contaminated site in Korea. Site ground water containing lactate(as electron donor and/or carbon source) and PCE was pumped into the soil columns. During the first operation with a period of 50 days, injected mass ratio of lactate and PCE was 620:1 and incomplete reductive dechlorination of PCE to cis-DCE was observed in the columns. However, complete dechlorination of PCE to ethylene was observed when the mass ratio increased to 5,050:1 in the second operation, suggesting that the electron donor might be limited during the first operation period. During the degradation of cis-DCE to ethylene, the concentration of hydrogen was $22{\sim}29mM$. These positive results indicate that the TCE-contaminated groundwater investigated in this study could be remediated through biological anaerobic reductive dechlorination processes.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권4호
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• pp.23-30
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• 2011

Risk based pollution level of Pb and Cd in metal contaminated soils depending on physicochemical properties of soil in a target site was assessed using biotic ligand model. Heavy metal activity in soil solution defined as exposure activity (EA) was assumed to be toxic to Vibrio fischeri and soil organisms. Predicted effective activity (PEA) determined by biotic ligand model was compared to EA value to calculate risk quotient. Field contaminated soils (n = 10) were collected from a formes area and their risk based pollution levels were assessed in the present study using the calculated risk quotient. Concentrations of Pb determined by aqua regia were 295, 258, and 268 mg/kg in B, H and J points and concentrations of Cd were 4.73 and 6.36 mg/kg in G and I points, respectively. These points exceeded the current soil conservation standards. However, risk based pollution levels of the ten points were not able to be calculated because concentrations of Pb and Cd in soil solution were smaller than detection limits or one (i.e., non toxic). It was because heavy metal activity in soil solution was dominant toxicological form to organisms, not a total heavy metal concentration in soil. In addition, heavy metal toxicity was decreased by competition effect of major cations and formation of complex with dissolved organic carbon in soil solution. Therefore, it is essential to consider site-specific factors affecting bioavailability and toxicity for estimating reliable risk of Pb and Cd.

• 대한지하수환경학회지
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• 제5권1호
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• pp.30-36
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• 1998

저분자량 유기산을 이용한 in-situ flushing 토양세척기법의 실제 현장 적용성 검토를 위해 실험실에서 회분식 실험을 통하여 적당한 세척제를 선정하고 이에 따른 여러 가지 운전변수를 찾아보았다. 대상 중금속으로는 Cu를 택했고, 세척제로는 실제 토양환경에 영향이 비교적 적은 저분자량 유기산인 acetic, citric, oxalic, succinic acid를 이용했다. 유기산을 이용하여 처리한 결과 실험에 사용된 유기산들 모두 1 mM의 저농도에서는 효과를 나타내지 못했고 50 mM 이상의 고농도에서 보다 좋은 제거율을 보였는데, 50 mM과 100mM의 경우 제거율이 큰 차이를 보이지 못했다. citric arid와 oxalic acid의 경우 중성 및 약산성 상태에서 최대의 제거율이 나타났고 특히 citric arid의 경우 87.1%의 높은 제거율을 보였다. 유기산이 없을때는 강산성 상태에서 Cu의 최고제거율이 70% 정도였다. 그러나 각 경우에서의 speciation을 살펴보면 유기산이 없을 경우에는 추출된 Cu의 대부분이 유해한 free ion상태로 존재하게 되고 유기산이 있을 경우에는 추출된 Cu의 대부분이 유기산과 complex를 이룬다는 것을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제19권12호
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• pp.1672-1678
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• 2009

We studied the effects of aged total petroleum hydrocarbons (aged TPH) on the survival of allochthonous diesel-degrading Rhodococcus sp. strain YS-7 in both laboratory and field investigations. The aged TPH extracted from a crude-oil-contaminated site were fractionized by thin-layer chromatography/flame ionization detection (TLC/FID). The three fractions identified were saturated aliphatic (SA), aromatic hydrocarbon (AH), and asphaltene-resin (AR). The ratio and composition of the separated fractions in the aged TPH were quite different from the crude-oil fractions. In the aged TPH, the SA and AH fractions were reduced and the AR fraction was dramatically increased compared with crude oil. The SA and AH fractions (2 mg/l each) of the aged TPH inhibited the growth of strain YS-7. Unexpectedly, the AR fraction had no effect on the survival of strain YS-7. However, crude oil (1,000 mg/l) did not inhibit the growth of strain YS-7. When strain YS-7 was inoculated into an aged crude-oil-contaminated field and its presence was monitored by fluorescent in situ hybridization (FISH), we discovered that it had disappeared on 36 days after the inoculation. For the first time, this study has demonstrated that the SA and AH fractions in aged TPH are more toxic to an allochthonous diesel-degrading strain than the AR fraction.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권2호
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• pp.1-9
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• 2013

The landfarming treatment for the remediation of the petroleum contaminated soil at the returned U.S. Military bases was investigated in this study. Specifically, the bioaugmentation performance using various commercially available petroleum-degrading bacteria was evaluated and the directions for enhancing the performance of the landfarming treatment were suggested. The environmental factors of the soils at the returned U.S. Military bases chosen for remediation indicate that the landfarming treatment can be used as the remediation technique; however, the addition of nitrogen or phosphorus is required. The lab-scale landfarming treatment tests using the model soil and the site soil showed that the degradation efficiency was greater with the model soil than the site soil and that the treatment performance was not affected by the number of bacteria present in the soil in the range of $10^6-10^{12}$ CFU/g. These results suggest that the successful landfarming treatment depends on the petroleum degradability of bacteria used and the environmental conditions during the treatment rather than the number of petroleum-degrading bacteria used.