• Journal of the Korean Society of Groundwater Environment
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• v.5 no.4
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• pp.177-191
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• 1998

For various kinds of waters including surface water, shallow groundwater (＜70 m deep) and deep groundwater (500∼810 m deep) from the Pungki area, an integrated study based on hydrochemical, multivariate statistical, thermodynamic, environmental isotopic (tritium, oxygen-hydrogen, carbon and sulfur), and mass-balance approaches was attempted to elucidate the hydrogeochemical and hydrologic characteristics of the groundwater system in the gneiss area. Shallow groundwaters are typified as the 'Ca-HCO$_3$'type with higher concentrations of Ca, Mg, SO$_4$and NO$_3$, whereas deep groundwaters are the 'Na-HCO$_3$'type with elevated concentrations of Na, Ba, Li, H$_2$S, F and Cl and are supersaturated with respect to calcite. The waters in the area are largely classified into two groups: 1) surface waters and most of shallow groundwaters, and 2) deep groundwaters and one sample of shallow groundwater. Seasonal compositional variations are recognized for the former. Multivariate statistical analysis indicates that three factors may explain about 86% of the compositional variations observed in deep groundwaters. These are: 1) plagioclase dissolution and calcite precipitation, 2) sulfate reduction, and 3) acid hydrolysis of hydroxyl-bearing minerals(mainly mica). By combining with results of thermodynamic calculation, four appropriate models of water/ rock interaction, each showing the dissolution of plagioclase, kaolinite and micas and the precipitation of calcite, illite, laumontite, chlorite and smectite, are proposed by mass balance modelling in order to explain the water quality of deep groundwaters. Oxygen-hydrogen isotope data indicate that deep groundwaters were originated from a local meteoric water recharged from distant, topograpically high mountainous region and underwent larger degrees of water/rock interaction during the regional deep circulation, whereas the shallow groundwaters were recharged from nearby, topograpically low region. Tritium data show that the recharge time was the pre-thermonuclear age for deep groundwaters (＜0.2 TU) but the post-thermonuclear age for shallow groundwaters (5.66∼7.79 TU). The $\delta$$\^$34/S values of dissolved sulfate indicate that high amounts of dissolved H$_2$S (up to 3.9 mg/1), a characteristic of deep groundwaters in this area, might be derived from the reduction of sulfate. The $\delta$$\^$13/C values of dissolved carbonates are controlled by not only the dissolution of carbonate minerals by dissolved soil CO$_2$(for shallow groundwaters) but also the reprecipitation of calcite (for deep groundwaters). An integrated model of the origin, flow and chemical evolution for the groundwaters in this area is proposed in this study.

• Economic and Environmental Geology
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• v.43 no.3
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• pp.211-222
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• 2010

A batch experiment was carried out to investigate a variation of Sr concentration and $^{87}Sr/^{86}Sr$ ratio in the solution by water-rock interaction. The experiments were conducted at room temperature using two kinds of granites (biotite granite and garnet-bearing granite), de-ionized water. surface water. Water/rock ratio was 1:1. For comparison, we also performed another experiment under water/rock condition of 10:1. Then, the concentration of the cations and anions in the solutions showed severe variation during water/rock interaction. However, after sometime, the $^{87}Sr/^{86}Sr$ ratio of the solution moved to the $^{87}Sr/^{86}Sr$ ratio of the rocks and showed relatively constant value. This suggests that the $^{87}Sr/^{86}Sr$ ratio between water and rock becomes to be stable faster than the elemental equilibration of the element in the solution, and is not affected by interaction condition. Therefore, $^{87}Sr/^{86}Sr$ ratio of the groundwater may be useful in calculating the mixing ratio between different aquifer.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.516-516
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• 2015

본 연구는 한강유역($2,6018km^2$)을 대상으로 SWAT(Soil and Water Assessment Tool)을 이용하여 지표수와 지하수의 상호작용에 의한 물수지 분석을 수행하고, 수량측면의 유역 건전성을 평가하였다. 유역의 물수지 분석을 위해 한강유역을 표준유역 단위로 구분하고, 기상자료, 하천유량, 다목적댐(소양강댐, 충주댐, 횡성댐) 운영자료, 다기능보(강천보, 여주보, 이포보) 운영자료, 증발산량, 토양수분 자료를 수집하였다. SWAT 모형의 신뢰성 있는 유출량 보정을 위해 한강유역 내 위치하는 다목적댐 및 다기능보의 실측 방류량을 이용하여 댐 운영모의를 고려하였고, 실측 지하수위, 증발산, 토양수분 자료를 이용하여 모형의 보정(2005~2009)과 검증(2010~2014)을 실시하였다. 그 결과 토양수분으로부터 증발산이 발생하고 유출 및 지하수까지 영향을 미치는 물수지 현상을 잘 재현하고 있음을 알 수 있었다. 이후 유역의 수량측면의 건전성 평가를 위한 수문요소로 하천 유출량, 증발산량, 침투, 침루, 기저유출, 토양수분, 지하수 함양량 등을 도출하고 유역의 물순환을 해석하여 유역의 건전성을 평가하였다.

• Economic and Environmental Geology
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• v.34 no.1
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• pp.71-88
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• 2001

The Geochemica] and isotope studies on the $CO_2$-rich water from the Shinchon area were carried out. The Shinchon $CO_2$-rich water belongs to Ca(Na)-$HCO_3$ type showing very high $P_{CO_{2}}$ ( $10^{-0.35}$ ~ $10^{0.29}$ atm) and TDS (835-3,144 mg/L). The results of geochemical and isotope analysis indicate that $CO_2$ gas is originated from the deep seated source such as mantle or magmatic gases. The $CO_2$-rich water was evolved by interaction with deep-seated granite and major water-rock interaction was dissolution of p]agioclase resulting high Na content of $CO_2$-rich water. Precipitation and dissolution of secondary calcite might be accompanied with the dissolution of plagioclase maintaining Na/Ca ratio. High contents of K and $SO_4$ indicate that the geochemical characteristics of $CO_2$-rich water were partially affected by interaction with upper sedimentary rock during uprising to surface. N03 and tritium contents suggest that the $CO_2$-rich water was mixed with low $CO_2$ groundwater at some locations. The oxygen-hydrogen isotopes show that all water samples were derived from meteoric waters and the $CO_2$-rich water was isotopically re-equilibrated with lighter $CO_2$ gas. Although some carbon isotope data show isotopically heavy values, carbon isotope data indicate that the $CO_2$ gas was possib]y derived by deep source.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.4
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• pp.199-211
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• 1997

As a part of study on geological disposal of radioactive waste, hydrogeochemical characteristics of deep granitic groundwater in Korea were investigated through the construction of a large geochemical dataset of natural water, the examination on the behaviour of dissolved constituents, and the consideration of phase stability based on thermodynamic approach. In granitic region, the contents of total dissolved solids increase progressively from surface waters to deep groundwaters, which indicates the presence of more concentrated waters at depth due to water-rock interaction. The chemical composition of groundwater evolves from initial $Ca^{2＋}$－(C $l^{－}$＋S $O_4$$^{2-}$) or $Ca^{2＋}$-HC $O_3$$^{－}$ type to final N $a^{＋}$-HC $O_3$$^{－}$ or N $a^{＋}$－(C $l^{－}$＋S $O_4$$^{2-}$) type, via $Ca^{2＋}$-HC $O_3$$^{－}$ type. Three main mechanisms seem to control the chemical composition of groundwater in the granitic region; 1) congruent dissolution of calcite at shallower depth, 2) calcite precipitation and incongruent dissolution of plagioclase at deeper depth, and 3) kaolinite-smectite or/and kaolinite-illite reaction at equilibrium at deeper depth. The behaviour of dissolved major cations (C $a^{2＋}$, $K^{＋}$, $Mg^{2＋}$, M $a^{＋}$) and silica is likely to be controlled by these reactions.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.179-183
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• 2010

본 연구는 낙동강 중류 지역의 경북 구미시, 경북 왜관읍, 경북 성주군과 하류 지역의 경남 함안군, 창원시 북면과 대산면, 김해시 생림면의 하성충적층 내 지하수와 낙동강물의 연관성을 파악하였다. 중류와 하류지역에서 하성충적층의 주 대수층(모래자갈층)의 두께는 10m 내외로서 공간적으로 큰 차이를 보이지는 않는다. 하성충적층의 수리전도도는 $10^{-5}{\sim}10^{-3}$m/sec를 나타낸다. 하성충적층의 지하수위는 지역에 따라 해수면 기준으로 1.40~11.5m에서 변동하며, 지하수위와 낙동강 수위는 높은 상관성을 보인다. 지하수와 낙동강물의 화학분석 결과, 칼슘, 마그네슘, 나트륨, 칼륨, 염소, 규산, 중탄산, 망간, 철과 같은 무기성분의 농도는 지하수에서 더 높게 나타나고 있으나, 질산염의 농도는 낙동강물에서 더 높게 나타난다. 지하수내의 유기물질의 농도는 계절에 관계없이 비교적 일정하나, 낙동강물의 유기물질 농도는 우기보다 건기에 더 높은 경향성을 보이고 있다. 이러한 연구결과는 4대강 살리기 사업이나 하천주변지역의 수자원 개발에 활용될 수 있을 것이다.

• Economic and Environmental Geology
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• v.34 no.5
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• pp.471-483
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• 2001

The pH values of the mine and surface water from the Tohyun mine creek were higher compared with those of groundwater, and 2nd round samples in same sites were even alkaline. The stream and mine waters belong to the characteristics of (Ca+Mg)-(SO$_4$) and (Ca+Mg)-(HCO$_3$) types, and groundwaters have to the (Ca+Mg+Na+K)-(HCO$_3$+SO$_4$) type. As the 2nd samples. concentrations of mostly anions are increasing compared with the forder samples. However, the mostly cation concentrations are decreasing. The hydrogeochemistry indicate that water quality is different chemical characteristics and evolution trends. The range of $\delta$D and $\delta$$^{18}$ valutes (relative to SMOW) in the waters are shown in -62.2 to -70.1$\textperthousand$, and -8.1 to -9.4$\textperthousand$. The values are plowed parallel to $\delta$D=8$\delta$$^{18}$ O+ (6$\pm$4). The d values of groundwater show 2.4, which is lower than the surface (5.2) and mine (7.6) waters. Strontium concentra titans range from 0.025 to 11.844 mg/$\ell$ in all kinds of water samples, but the groundwater has the highest contents The $^{87}$ Sr/$^{86}$ Sr ratios (0.7115 to 0.7129) show more lightened to the groundwater. The $\delta$$^{18}$ O value, Ca and Sr contents are decreased with $^{87}$ Sr/$^{86}$ Sr increasing, because it is support to the altitude effects of the sampling sites rather than a water-rock interaction of environmental isotope. Using computer code of WATEQ4F, saturation indices of albite, Quartz, gibssite and gypsum are calculated to be soluble. The calcite and dolomite show super saturation state, however, clay mineral species are plotted boundary between undersaturation and supersaturation. In the Tohyun mine creek, reaction materials with ore wastes arid precipitation have influence upon increasing EC and TDS of the waters independent of pH. The SO$_4$ concentrations in the mine water is 181.845 mg/$\ell$. This is abruptly increase in surface water and then detected 249.727 mg/$\ell$ in the groundwater. As a results of the calculated sulfate mineral solubilities, the sulfate ions became saturation states an above 150 mg/$\ell$ concentrations.

• Journal of the Korean GEO-environmental Society
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• v.16 no.12
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• pp.37-43
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• 2015

Ground characteristics is important in tunnel structure utilizing the strength of underground. In the case of the fault fracture zone such as weak soil conditions exists in the tunnel section and groundwater leaching occurs at the same time, it happens to occur to excessive displacement or collapse of tunnel frequently. Fault fracture zone is an important factor that determines the direction of displacement and the collapse of the tunnel under construction. Behavior of fault fracture zone is determined depending on the size and orientation of the surface portion of the tunnel. If the groundwater occurs in the face of tunnel, groundwater causes displacement and collapse. And the collapse characteristics of tunnel is a major factor in determining that the time-dependent behavior. It is difficult to accurately predict groundwater leaching from the fault fracture zone in the numerical analysis method and analyze the interaction behavior of groundwater and fault fracture zone. Therefore numerical analysis method has limitations the analysis of ground water in the ground which the fault fracture zone and groundwater occurs at the same time. It is required to comprehensively predict the behavior of tunnel and case studies of tunnel construction. Thus, the location of fault fracture zone is an important factor that determines the direction of displacement and the collapse of the tunnel. In this study, behavior characteristics of the tunnel according to the location of the fault fracture was analyzed.

• Journal of Soil and Groundwater Environment
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• v.18 no.7
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• pp.81-89
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• 2013

Concerns have been raised over the impact of nano materials on soil and groundwater environment with the increasing attention to the potential applications of carbon nano materials in various fields. Particularly, carbon nano materials introduced into water environment readily make complexes with humic acid (HA) due to their hydrophobic nature, so there have been increasing numbers of studies on the interaction between HA and carbon nano materials. In this study, we investigated the solubility of HA and multiwalled carbon nanotubes (MWCNT) in three different surfactant solutions of sodium dodecyl sulfate (SDS), Brij 30 and Triton X-100, and evaluated whether the HA can be effectively desorbed from the surface of MWCNT by surfactant. The objective of this study was to determine the optimal adsorption condition for HA to MWCNT. Futhermore, sodium dodecyl sulfate (SDS), Brij 30, Triton X-100 were used to elucidate the effect of desorption and separation on adsorbed HA on MWCNT. As a result, HA solution with 12.7 mg of total organic carbon (TOC) and 5 mg of MWCNT showed the highest adsorption capacity at pH 3 reacted for 72 hrs. Weight solubilizing ratio (WSR) of surfactants on HA and MWCNT was calculated. HA had approximately 2 times lower adsorption capacity for the applied three surfactants compared to those of MWCNT, implying that the desorption of HA may occur from the HA/MWCNT complex. According to the results of adsorption isotherm and weight solubilizing ratio (WSR), the most effective surfactants was the SDS 1% soluiton, showing 53.63% desorption of HA at pH 3.

• Journal of Soil and Groundwater Environment
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• v.21 no.1
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• pp.86-93
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• 2016

Fenton is the reaction using the OH· radicals generating by interaction between hydrogen peroxide and Fe²⁺ which can oxidize the contaminants. Fe²⁺ ions are oxidized to Fe³⁺ ions by reaction with H₂O₂ and formed OH· radicals. UV-Fenton process includes the additional reaction that generates the OH· radicals by photodegradation of H₂O₂. In methylorange (MO) decolourization experiment with UV-Fenton, optimal Fe²⁺: H₂O₂ ratio was obtained at 1 : 10. Based on the obtained condition (H₂O₂= 10mM, Fe²⁺ = 1 mM) with/without UV-fenton experiment was carried out. Removal efficiency and sludge production were measured at 30 min. The case of w/o UV irradiation and only H₂O₂ was hardly treated and only Fe²⁺ showed 65% removal owing to coagulation. When UV-Fenton process in optimal ratio (Fe²⁺: H₂O₂ = 1 : 10), UV irradiation showed better removal efficiency than of w/o UV irradiation. Also, MO decolourization was a function of the hydrogen peroxide concentration (x₁), Fe²⁺:H₂O₂ ratio (x₂), and numbers of UV lamp (x₃) from the application of the response surface methodology. Statistical results showed the order of significance of the independent variables to be hydrogen peroxide concentration > numbers of UV l amp > Fe²⁺: H₂O₂ ratio.