• Title/Summary/Keyword: Geoenvironmental

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Spatio-Temporal Variation of Polymetallic Mineralization in the Wooseok Deposit (우석광상 다금속 광화작용의 시공간적 특성변화)

  • Im, Heonkyung;Shin, Dongbok;Jeong, Junyeong;Lee, Moontaek
    • Economic and Environmental Geology
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    • v.51 no.6
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    • pp.493-507
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    • 2018
  • The Wooseok deposit in Jecheon belongs to the Hwanggangri Mineralized Distict of the northeastern Ogcheon Metamorphic Belt. Its geology consists mostly of limestone of the Choseon Supergroup and the Cretaceous Muamsa granite intruded at the eastern area of the deposit. The deposit shows vertical occurrence of skarn and hydrothermal vein ores with W-Mo-Fe and Cu-Pb-Zn mineralization and skarn is developed only at lower levels of the deposit. Skarn minerals are replaced or cut by ore minerals in paragenetic sequence of magnetite-hematite, molybdenite-scheelite-wollframite, and higher abundances of pyrrhotite-chalcopyrite-pyrite-sphalerite-galena. Garnet has chemical compositions of $Ad_{65.9-97.8}Gr_{0.3-32.0}Pyr_{0.9-3.0}$, corresponding to andradite series, and pyroxene compositions are $Hd_{4.5-49.7}Di_{42.3-93.9}Jo_{0.5-7.9}$, prevailing in diopside compositions, both of which suggest oxidized conditions of skarnization. On the FeS-MnS-CdS ternary diagram, FeS contents of sphalerite in vein ores decrease with increasing MnS contents from bottom to top levels, possibly relating to W mineralization in deep and Pb-Zn mineralization in shallow level. Sulfur isotope values of sulfide minerals range from 5.1 to 6.8‰, reflecting magmatic sulfur affected by host rocks. W-Mo skarn and Pb-Zn vein mineralization in the Wooseok deposit were established by spatio-temporal variation of decreasing temperature and oxygen fugacity with increasing sulfur fugacity from bottom to top levels.

A Provenance Study of Iron Archaeological Sites in the Gyeongsang Province: Petrographic and Geochemical Approaches (경상지역 제철유적의 산지추정 연구: 암석기재학 및 지화학적 접근)

  • Jaeguk Jo;Seojin Kim;Jiseon Han;Su Kyoung Kim;Dongbok Shin;Byeongmoon Kwak;Juhyun Hong;Byeongyong Yu;Jinah Lim
    • Economic and Environmental Geology
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    • v.56 no.4
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    • pp.475-499
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    • 2023
  • To infer the provenance of raw iron materials utilized in iron production at the archaeological sites in Gyeongsang province, petrographic and geochemical analyses were conducted for smelting samples and major iron ores sourced from ore deposits. The smelting samples excavated from various iron archaeological sites were classified into different types according to their refining processes, such as iron bloom, iron bloom slag, pig iron, pig iron slag, forging iron flake, smithery iron, iron flake, and arrowhead. These samples exhibited discernable differences in their mineralogical components and texture. The enrichments of major elements such as aluminum and calcium in silicate minerals of the residual slags and the high contents of trace elements such as nickel and copper in some iron-making relics reflect the characteristics of raw iron ores, and thus can be regarded as potential indicators for inferring the provenance of source materials. In particular, the compositional ranges of Pb-Sr isotope ratios for the iron smelting samples were classified into three categories: 1) those exhibiting similar ratios to those of the raw iron ores, 2) those enriched in strontium isotope ratio, and 3) those enriched in both lead and strontium isotope ratios. The observed distinct Pb-Sr isotope characteristics in the iron smelting samples suggest the potential contribution of specific additives being introduced during the high-temperature refining process. These results provide a new perspective on the interpretation of the provenance study of the iron archaeological samples in Gyeongsang province, particularly in terms of the potential contribution of additives on the refining process.

Chemical Treatment of Municipal Wastewater Using Alum Sludge

  • Shin, Dae-Yewn;Moon, Ok-Ran;Yoon, Mi-Ran;Ro, Chang-Wha;Kang, Gong-Unn;Moon, Deok-Hyn;Dermatas, Dimitris
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2005.12a
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    • pp.51-53
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    • 2005
  • Disposal of waterwork sludge is important problem in WTP(water treatment plant). Purpose of this study is treated municipal waste water chemically using sludge that is produced in waterwork plant by link to reutilize waterwork sludge. Municipal waste water that use in an experiment used is produced at C university, and is SS 220 mg/L, BOD 145 mg/L, COD 160 mg/L, T-N 52 mg/L and T-P 2.6 mg/L. Used Alum, polymer coagulant and coagulant aid (diatomite, powered activated carbon) as CaO, coagulant as alkaline aid by chemical treatment medicine. In case of does slow speed agitation and stations after pours waterwork sludge in sewage and alkaline aid and coagulant at rapidly mixing the colloidal creation speed is fast and fine colloids concentration was high but settling time is shortened a little and removal rate of pollutant improved by $60{\sim}99%$.

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Development of 3-Dimensional Stress Measurement System by Bore hole Bottom Deformation Method (공저변형법에 의한 3차원응력측정 시스템의 개발)

  • Lee, Ki-Ha;Ishijima, Yoji;Fujii, Yoshiaki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.34-41
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    • 2006
  • A 3-dimensional stress measurement system based on the bore hole bottom deformation method, which is one of the stress relief methods, was developed. A pilot bore hole is drilled from the bottom of a bore hole and the stress meter is inserted into the pilot bore hole in the method. The bore hole is advanced as an over coring and the deformations in seven directions are measured by cantilever type-sensors. Using the cantilever type-sensors saves time for hardening of glue. No cable connection between the stress meter and a data logger is necessary since a compact data logger is installed in the stress meter. The accuracy of the stress meter was confirmed by a biaxial test for a Shikotsu welded tuff block although in-situ tests have not been carried out yet.

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Hydro-thermal Numerical Simulation for an Artificial Recharge Test in a Fractured Rock Aquifer (암반대수층 지하수 인공함양 시험에 대한 열-수리 모델링)

  • Park, Daehee;Koo, Min-Ho;Kim, Yongcheol
    • Journal of Soil and Groundwater Environment
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    • v.20 no.1
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    • pp.65-75
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    • 2015
  • An artificial recharge test aimed at investigating transport characteristics of the injected water plume in a fractured rock aquifer was conducted. The test used an injection well for injecting tap water whose temperature and electrical conductivity were different from the groundwater. Temporal and depth-wise variation of temperature and electrical conductivity was monitored in both the injection well and a nearby observation well. A highly permeable fracture zone acting as the major pathway of groundwater flow was distinctively revealed in the monitoring data. A finite element subsurface flow and transport simulator (FEFLOW) was used to investigate sensitivity of the transport process to associated aquifer parameters. Simulated results showed that aperture thickness of the fracture and the hydraulic gradient of groundwater highly affected spatio-temporal variation of temperature and electrical conductivity of the injected water plume. The study suggests that artificial recharge of colder water in a fractured rock aquifer could create a thermal plume persistent over a long period of time depending on hydro-thermal properties of the aquifer as well as the amount of injected water.

Distribution of Alluvium Depth by the Ordinary Kriging of Vertical Electrical Sounding Data (전기비저항 수직탐사 자료의 정규크리깅을 통한 충적층 분포도의 작성)

  • Jung, Yeon-Ho;Byun, Joong-Moo
    • Geophysics and Geophysical Exploration
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    • v.10 no.3
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    • pp.211-218
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    • 2007
  • In this study, vertical electrical sounding (VES) data and ordinary kriging are used to identify the alluvial depth of each area that Korea Resources Corporation (KORES) conducted groundwater survey at Miryang area in Gyeongsangnam-do and Pocheon area in Gyeonggi-do from 2003 to 2004. To verify the applicability of VES data to ordianry kriging, regression analysis of VES data versus drillhole data is conducted. Comparing the alluvial depth distributions using ordinary kriging with existing drillhole data, the result shows that the depth distributions are reasonably depicted along with the topography and the basin. So, the ordinary kriging of VES data is useful to identify the alluvial depth distributions.

CHEMICAL COMPATIBILITY OF SOIL-BENTONITE CUT-OFF WALL FOR IN-SITU GEOENVIRONMENTAL CONTAINMENT

  • Inui, Toru;Takai, Atsushi;Katsumi, Takeshi;Kamon, Masashi;Araki, Susumu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.135-139
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    • 2010
  • A construction technique to install the soil-bentonite (SB) cut-off wall for in-situ geoenvironmental containment by employing the trench cutting and re-mixing deep wall method is first presented in this paper. The laboratory test results on the hydraulic barrier performance of SB in relation to the chemical compatibility are then discussed. Hydraulic conductivity tests using flexible-wall permeameters as well as swell tests were conducted for SB specimens exposed to various types and concentrations of chemicals (calcium chloride, heavy fuel oil, ethanol, and/or seawater) in the permeant and/or in the pore water of original soil. For the SB specimens in which the pore water of original soil did not contain such chemicals and thus the sufficient bentonite hydration occurred, k values were not significantly increased even when permeated with the relatively aggressive chemical solutions such as 1.0 mol/L $CaCl_2$ or 50%-concentration ethanol solution. In contrast, the SB specimens containing $CaCl_2$ in the pore water had the higher k values. The excellent linear correlation between log k and swelling pressure implies that the swelling pressure can be a good indicator for the hydraulic barrier performance of the SB.

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Determining Optimal Locations of an Artificial Recharge Well using an Optimization-coupled Groundwater Flow Model (지하수 모델링 기법을 이용한 인공함양정 최적 위치 평가)

  • Lee, Hyeonju;Koo, Min-Ho;Kim, Yongcheol
    • Journal of Soil and Groundwater Environment
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    • v.19 no.3
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    • pp.66-81
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    • 2014
  • A Fortran program was developed to determine the optimal locations of an artificial recharge well. Three objective functions were considered: (1) maximizing the recovery rates, (2) maximizing the injection rates, and (3) minimizing the coefficient of variation of the increased pumping rates. We also suggested a new aggregate objective function which combined the first and the third objective functions. The model results showed that locating the injection well inside the cluster of pumping wells was desirable if either the recovery or the injection rate was taken into account. However, the injection well located outside the cluster evenly increased the pumping rates in existing pumping wells. Therefore, for clustered pumping wells, installing an injection well at the center or the upstream of the pumping wells seems beneficial. For linear arrangement of pumping wells parallel to the constant head boundary, locating the injection well in the upstream was recommended. On the contrary, in case of the linear arrangement perpendicular to the constant head boundary, the injection well installed on both sides of the central part of the pumping wells was preferable.