• 한국지하수토양환경학회지:지하수토양환경
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• 제20권6호
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• pp.62-72
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• 2015

This study investigates the in-situ implementation of bio-regenerated iron mineral catalyst to remove explosive compounds in ground water at a military shooting range in operation. A bio-regenerated iron mineral catalyst was synthesized using lepidocrocite (iron-bearing soil mineral), iron-reducing bacteria Shewanella putrefaciens CN32, and electron mediator (riboflavin) in the culture medium. This catalyst was then injected periodically in the ground to build a redox active zone acting like permeable reactive barrier through injection wells constructed at a live fire military shooting range. Ground water and core soils were sampled periodically for analysis of explosive compounds, mainly RDX and its metabolites, along with toxicity analysis and REDOX potential measurement. Results suggested that a redox active zone was formed in the subsurface in which contaminated ground water flows through. Concentration of RDX as well as toxicity (% inhibition) of ground water decreased in the downstream compared to those in the upstream while concentration of RDX reduction products increased in the downstream.

• 자원환경지질
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• 제39권5호
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• pp.537-554
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• 2006

유성지구 지열수의 산출 특성 및 수리적 연결성을 파악하기 위하여 2002년 3월부터 2005년 6월까지 장기 수위 관측을 실시하였다. 관측된 수위 자료를 이용하여 수위변동 주기 분석을 실시한 결과, 대부분의 관측공에서 0.5일, 1일, 7일 주기성이 확인되었다. 7일 주기성은 온천지대에서의 독특한 양수 행태로 인해 발생되는 인위적 현상으로서, 연구 지역내 관측공들의 수리적 연결성이 양호한 것을 반영하였다. 수위 영향 관계를 분석한 결과, E-W 방향성과 N-S 방향성의 지질구조가 지열수 저류체의 발달 및 지열수 유동에 중요한 규제 요소로 작용되고 있음이 확인되었다. 전반적으로 지열수의 열원과 대수층의 수리적 연결성과는 상호 연관성이 있을 것으로 해석된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제28권5호
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• pp.12-24
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• 2023

The Songji lagoon is brackish environment with a mixture of saline and fresh water, and the interaction of groundwater-lagoon water creates a physicochemical gradient. Although some studies have been conducted on the hydrological and geochemical characteristics of the Songji lagoon, microbial ecological studies have not yet been conducted. In this study, we investigated the effect of groundwater and surface water interaction on water quality as well as microbial community changes in the Songji Lagoon using 16S rRNA gene sequencing. Hydrochemical analyses show that samples were classified as 5 hydrochemical facies (HF) and hydrochemical facies evolution (HFE) revealed the intrusion phase was more dominant (57.9%) than the freshening phase (42.1%). Higher microbial diversity was found in freshwater in comparison to saline water samples. The microbial community at the phylum level shows the most dominance of Proteobacteria with an average of 37.3%, followed by Bacteroidota, Actinobacteria, and Patescibacteria. Heat map analyses of the top 18 genera showed that samples were clustered into 5 groups based on type, and Pseudoalteromonas could be used potential indicator for seawater intrusion.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권3호
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• pp.1-13
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• 2024

This study investigated the hydrogeochemical and microbiological characteristics of freshwater on Ulleung Island, a volcanic island in the Ulleung Basin on the East Coast of Korea. The shallow groundwater (CSW, NRGW) and the surface water (SISW) samples are classified as Na-HCO₃ type, reflecting an alkaline rock type and an oxidizing environment due to the influence of a highly permeable pyroclastic rock layer. In contrast, the deep groundwater sample (DMW) is classified as Ca-HCO₃ type, suggesting the influence of deep-sourced carbon dioxide and reducing conditions. Microbial communities in the water samples are generally dominated by Proteobacteria, with the relative abundance of major genera varying depending on water quality and environmental conditions. Network analysis reveals the ecological characteristics of microbial communities adapted to specific environments. The presence of pathogenic genera in the shallow groundwater suggests potential groundwater contamination, necessitating appropriate management to ensure its use as drinking water or domestic water. The findings of this study provide valuable insights into the ecological characteristics of Ulleung Island's groundwater resources and can inform future groundwater management strategies.

• 분석과학
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• 제24권1호
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• pp.10-14
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• 2011

먹는 물 중 bromide의 국내 외 시험방법에 대한 분석 조건을 비교하여 최적 시험조건을 확인하고 ion chromatograph-suppressed conductivity detector (IC-CD)를 사용하여 먹는 샘물 및 지하수 원수 중 bromide 함량을 분석하였다. 지하수 원수 중 bromide농도와 먹는 샘물 중 bromide 및 bromate 의 농도 합과의 상관관계를 조사하였다. 시료 전처리를 위해 먹는 샘물 20 mL를 온가드 Ba-, H-카트리지 순서대로 통과시키고 마지막에 $0.2\;{\mu}m$ 맴브레인 필터로 여과 하였다. 여과한 시료는 IC-CD에 주입하였으며, 시료 중 bromide는 10~50 mM의 수산화이온용액 이동상에 적합한 가드 및 분석용 컬럼인 AG 19 및 AS 19에 의해 분리하였다. Bromide의 검정 곡선은 $0.5\sim80\;{\mu}g/L$의 농도 범위에서 $r^2$값이 0.9993으로 좋은 직선성을 보였으며, 검출한계(MDL) 및 정량한계(LOQ)는 각각 0.2, $0.5\;{\mu}g/L$이었다. 실제 먹는 샘물 23 개와 먹는 샘물 공장의 지하수 원수 75 개의 시료 중 bromide를 분석한 결과, 각각 평균농도는 $14.7\;{\mu}g/L$, $20.4\;{\mu}g/L$이었다. 지하수 원수 중 bromide농도와 먹는 샘물 중 bromide 및 bromate의 농도 합과의 상관계수(r)는 0.808이었다.

• 한국지반환경공학회 논문집
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• 제21권11호
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• pp.11-20
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• 2020

연약지반 차수 및 보강용 그라우트에 대하여 다양한 양생조건에서 초기 및 장기재령에 걸쳐 내구성에 대한 검토를 수행하였다. 그라우트는 물유리계, 급결광물계 및 아크릴고분자계를 대상으로 하였으며, 양생조건은 수도수(청수) 양생, 인공해수 양생 및 대기 양생으로 하고, 시험은 재령별 일축압축강도와 길이변화량 및 중량변화량에 대하여 수행하였다. 인공해수는 MgCl₂와 MgSO₄ 수용액을 각각 제조하여 사용하였다. 급결광물계와 아크릴고분자계는 수도수와 인공해수에서는 내구성에 큰 변화가 없이 안정적으로 양생되는 반면 물유리의 경우 수도수에 비해 인공해수조건에서 매우 급격한 내구성 저하가 발생되었다. 대기 양생조건에서는 모든 경우에서 수도수 양생에 비해 내구성이 저하되는데, 특히 급결광물계와 물유리계에서 중량감소가 각각 약 62% 및 60%로 큰 내구성 저하가 발생되었다.

• 한국건축시공학회지
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• 제4권4호
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• pp.87-94
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• 2004

As the bentonite is main material to prevent from collapse of drilling hole at underground excavation works, it is increased using quantity on construction industry day by day. But, the discarded bentonite that is over using at underground excavation works is caused various enviromental trouble as soil and water pollution est. Therefore, this study aims to propose a foundamental report for pozzolan reaction of discarded Bentonite powder by heat-treatment and cooling as concrete mineral admixture. To find out pozzolan reaction ability of discarded Bentonite powder by indirect cooling & cooling using of water after heat-treatment, the experiments are excuted flow test & compressive strength on age of mortar using discarded Bentonite powder. As a result of this study, discarded Bentonite powder can be utilized as concrete mineral admixture by heat-treatment and especially, pozzolan reaction ability of discarded Bentonite powder is superior to the situation of 600℃. 60min ＆amp; cooling using of water.

• 한국지열·수열에너지학회논문집
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• 제4권1호
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• pp.1-10
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• 2008

A magnetotelluric survey and geological survey have been performed to delineate deeply extended fracture systems at the geothermal field in Seokmo Island, Inchon, Korea. One borehole(BH-1) succeed to meet a large fracture system at the depth of 750 m where approximately $72^{\circ}C$ geothermal water is overflowing, while the other borehole(BH-2), which is about 200 m eastward from BH-1, failed to develop enough geothermal water even at the depth of 1,200m. Though there have been so many electric noise sources around the survey region, good quality of MT data above 1 Hz could be obtained with careful installation, remote reference processing. Inversion of MT data for two lines roughly perpendicular to the two major lineaments respectively show that the two lineaments are related to the fracture systems that are extended at least down to 1.5 km depth and inclined eastwards. From the interpretation, additional drilling for BH-2 is recommended and finally meet the fracture systems at the depth of 1,280 m and resulted in overflow of large amount of geothermal water of temperature $69.4^{\circ}C$ from BH-2.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.736-742
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• 2010

This study was conducted to characterize on the relationships of rainfall intensity and infiltration rate of rainfall dependent on unit weight change in the gneissic weathered soil by a column test equipment. In this study, volumetric water content and pore water pressure were measured using TDR sensors and tensiometers at regular time intervals. Rainfall conditions including continuous rainfall and repeated rainfall were selected in order to know the effect of antecedent rainfall. In the condition of rainfall intensity 20mm/h and the unit weights of soil as $1.35g/cm^3$, $1.55g/cm^3$ and $1.61g/cm^3$, average rainfall infiltration rate was $2.814{\times}10^{-3}cm/sec$, $1.969{\times}10^{-3}cm/sec$ and $1.252{\times}10^{-3}cm/sec$ respectively. The higher rainfall intensity and lower unit weight of soil, the faster average infiltration rate. Overflow in the column was happened except rainfall condition of rainfall intensity 20mm and soil unit weight $1.35g/cm^3$. Increasing the soil unit weight, overflowed water was increased and occurrence time was faster.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.23.2-29
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• 2003

As the bentonite is main material to prevent from collapse of drilling hole at underground excavation works, the quantity of bentonite is increasingly used on construction industry day by day. But, the discarded bentonite that is excessively used at underground excavation works causes various environmental trouble such as soil and water pollution etc. Therefore, this study aims to propose a foundamental report about pozzolan reaction of discarded Bentonite powder by heat-treatment and cooling as concrete mineral admixture. To find out the strength-development properties of mortar with discarded Bentonite powder by indirect cooling & cooling using of water after heat-treatment, the experiments such as flow test, and compressive strength test on curing age of mortar are excuted. As a result of this study, discarded Bentonite powder can be utilized as concrete mineral admixture by heat-treatment and especially, the strength-development properties of mortar mixing with discarded Bentonite powder is superior to the situation of $600^{\circ}C$.60min-cooling using of water.