• Title/Summary/Keyword: saturated clay

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A Study on the Geochemical Clogging for the Assessment of the Hydrological Safety of the Underground Oil Storage Carvern (지하유류비축기지 수리안정성 평가를 위한 광물학적 클로깅 가능성 연구)

  • Kim, Geon-Young;Bae, Dae-Seok;Choi, Byeong-Young;Oh, Se-Joong;Koh, Yong-Hwon
    • Journal of the Mineralogical Society of Korea
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    • v.21 no.2
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    • pp.139-159
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    • 2008
  • Geochemical analysis of the various kinds of water including observation borehole groundwater was carried out for the assessment of the hydrological safety of the underground oil storage cavern and the potentiality of mineralogical and microbiological clogging was estimated. Most of water samples belonged to $Ca-HCO_3$ and $Ca-HCO_3-SO_4$ types. There was no distinct chemical difference in the various kinds of water. All kinds of water are undersaturated with the calcite which is the major clogging mineral. Most water samples have low Fe and Mn concentrations. However, they are saturated or oversaturated with the iron-oxide/hydroxide minerals and have high dissolved oxygen contents which suggests the possibility of clogging by the iron-oxide/hydroxide minerals as a long-term aspect. Several water samples from the ground observation borehole also show the high saturation indices far the clay minerals, which can fill up the fractures, indicating the possibility of clogging by the clay minerals. Statistical analysis shows the degree of mineral precipitation or dissolution is mainly controlled by pH, Eh and DO of water samples. According to the microbial analysis, the aerobic microbes and slime forming bacteria are dominant in most water samples and anaerobic microbes including sulfate reducing bacteria are very low or not detected. Although the slime forming bacteria which are known as a main microbial cause of the clogging is lower than $10^5\;CFUs/mL$ in all water samples, because the slime forming bacteria are dominant microbe in several observation boreholes, the clogging can be caused by it as a long-term aspect. In addition, the possibility of clogging can be increased if the microbial effect is combined with the mineralogical effect such as iron oxide/hydroxide minerals for the possibility of clogging. Therefore, the systematic and long-term program for the assessment of clogging is required for the safe operation of underground oil storage cavern.

Hydrogeochemistry of Some Abandoned Metal Mine Creeks in the Hwanggangri Mining District, Korea : A Preliminary Study (황강리 광화대에 분포하는 일부 폐금속 광산수계의 수리지구화학적 특성 : 예비연구)

  • 이현구;이찬희;이종창
    • Journal of the Korean Society of Groundwater Environment
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    • v.6 no.4
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    • pp.194-205
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    • 1999
  • Hydrogeochemical variation and environmental isotope at the some abandoned metal mine (Sanggok, Keumsil, Jangpung and Samdeok) creeks of the Hwanggangri mining district were carried out based upon the physicochemical properties for surface water collected of February in 1998. Hydrogeochemical composition of the all water samples are characterized by the relatively significant enrichment of Ca$^{2}$, alkaline ions, N $O_3$$^{-}$ and Cl$^{-}$ in normal surface water, whereas the surface waters near the mining area are relatively enriched in Ca$^{2+$, Mg$^{2+}$, heavy metals. HC $O_3$$^{-}$ and S $O_4$$^{2-}$. Surface waters of the mining creek have low pH, high EC and extremely high concentrations of TDS compared with surface water of the non-mining creeks. The range of $\delta$D and $\delta$$^{18}$O values (SMOW) in the waters are shown in -65.0 to-71.2$\textperthousand$ and -9.1 to-10.2$\textperthousand$. The d($\delta$D-$\delta$$^{18}$O) value with those of water samples ranged from 7.3 to 10.9. These $\delta$D and $\delta$$^{18/}$ of the acid mine water are more heavy values than those of surface water. The values have revealed the positive correlation between isotopic compositions and major elements, because those $\delta$D and $\delta$$^{18}$O values increase with increasing TDS. HC $O_3$$^{-}$ , S $O_4$$^{2-}$ and Ca$^{2+}$ concentration. Using WATEQ4F, saturation index of albite calcite, dolomite and mostly clay minerals in water of the mining area show undersaturated and progressively evolved toward the equilibrium condition due to fresh water mixing, however, surface waters of the non-mining area are nearly saturated and/or supersaturated. Geochemical modeling showed that mostly toxic heavy metals within water in the mining creek may exist largely in the from of metal-sulfate (MS $O_4$$^{2-}$), free metal (M$^{2+}$/), C $O_3$$^{-}$ and/or OH$^{-}$ complex ions. Based on the geology, water chemistry and environmental istopic data the water compositions from the Sanggok and Keumsil mine creek (consist mainly of Cambro-Ordovician carbonate rocks of the Cho-seon Supergroup) show higher PH, Ca$^{2+}$, Mg$^{2+}$ , HC $O_3$$^{-}$ and more heavy $\delta$D and $\delta$$^{18}$O values than those from the Jangpung and Samdeok mine creek (consist of age -unknown metasedimentary rocks of the Ogcheon Supergroup and/or Jurassic grani-toids), but each of these waters represents a similar hydrogeochemical evolution path by the mine water mixing.

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The Effects of Geological and Topographical Features on Landslide and Land-creep (지질(地質)과 지형(地形)이 산사태(山沙汰) 및 땅밀림에 미치는 영향(影響))

  • Jau, Jae-Gyu;Park, Sang-Jun;Son, Doo-Sik;Joo, Sung-Hyun
    • Journal of Korean Society of Forest Science
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    • v.89 no.3
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    • pp.323-334
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    • 2000
  • This study was carried out to investigate the effects of geological and topographical features on landslide and land-creep at the twenty four surveyed sites of Kyungpook province. According to the results obtained, it was concluded that continuous heavy rainfall was one of the primary factors to occur landslide and land-creep. Most of the landslides occurred in the past were concentrated in the granite and granitic gneiss zones, while land-creeps were mainly occurred in the mud-stone zones. Therefore, it was thought that the physical properties such as soil texture, solid phase, moisture contents, density, hardness and porosity rate of weathered granite and granitic gneiss could affect the occurrence of landslide and land-creep. Due to the holding of sand contents in the upper soil layers of weathered granite and granitic gneiss, rainfall could infiltrate into the soil easily. While lower soil layers contained much quantity of clay and silt contents, those soils saturated with rainfall cause to lose viscosity and shear strength. Therefore, it was seemed that landslide was occurred more easily and the saturation of those soils was made much easily by bed rocks under those soils. Landslide and land-creep are slided into lower place by gravitation and slope degree factors. Therefore, prediction of landslide occurrence is very difficult because landslide is occurred abruptly, and physical properties of the soil have to be understood and checking the existence of bed rocks under the soils is not easy, on the other hand, land-creep is progressed very slowly. Therefore, it was suggested that in a degree creeping could be protected by removing of several causing factors.

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