• Title/Summary/Keyword: 토양제염

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Development of Electrokinetic-Flushing Equipment for a Remediation of Soil Contaminated with Radionuclides (방사성오염토양 제염을 위한 동전기세정장치 개발)

  • Kim, Gye-Nam;Jung, Yun-Ho;Lee, Jung-Joon;Moon, Jei-Kwon;Jung, Chong-Hun;Chung, Un-Soo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.6 no.1
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    • pp.1-9
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    • 2008
  • This study examined the effect of an electrokinetic-flushing remediation for a soil of a high permeability. The soil was sampled from the site around a research atomic reactor which had high hydro-conductivities due to a high content of sand in the soil. The flow rate of the washing reagent was fast at the beginning but it was reduced as time lapsed. In the case of using citric acid as a washing reagent, the flow rate was fastest, 78.7 ml/day. The removal efficiencies of $Co^{2+}$ and $Cs^+$ from a soil cell with acetic acid were the highest, which were 95.2% and 84.2% respectively. The soil waste-solution volume generated from the electrokinetic remediation was reduced to about 1/20 of that from the soil washing remediation. Meanwhile, the electrokinetic-flushing method enhanced the removal efficiencies of $Co^{2+}$ and $Cs^+$ from the soil by about 6% and 2% respectively, compared to those by the electrokinetic method. Consequently, it was found that the electrokinetic-flushing method was more effective for the remediation of a soil with a high permeability.

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The Solution of Upward Salt Diffusion in Floodeol Soil using Laplace Transformation (침수상태(湛水狀態)에서 토양(土壤) 염분(鹽分) 확산(擴散) 상승(上昇) 해석(解析)에 Laplace변환 이용)

  • Oh, Yong-Taeg;van der Molen, W.H.
    • Korean Journal of Soil Science and Fertilizer
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    • v.28 no.3
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    • pp.233-240
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    • 1995
  • Fick's diffusion equation was transformed into algebraic subsidiary equation with its initial and boundary conditions through Laplace transformation, and the subsidiary equation was transformed back on the basis of Burington's table of inverse transformations so that it became the solution of Fick's equation. The initial and boundary condition was for upward diffusion of salts into flooding water of constant depth from uniform polder soil of infinite depth containing constant concentration of salt. The derived solution was tested through comparison for its conformability with other solutions of simpler initial and boundary conditions. The importance of shallow transplanting of rice seedlings and salt removing by growing rice was mentioned on the basis of very slow desalting rate by diffusion calculated from the derived solutions.

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Desalinization of marine soil by the application of straw and lime (개흙의 제염에 미치는 볏짚, 석회의 병용효과)

  • Oh, Wang-Keun
    • Korean Journal of Soil Science and Fertilizer
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    • v.24 no.1
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    • pp.35-40
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    • 1991
  • A laboratory column experiment was conducted to learn the desalinization effect of rice straw, fresh or predecayed in limed marine soil, compared with gypsum. One third of Ca equivalent to indigenous Na plus Mg of the soil was applied to the top 10g out of 80g of total column soil, mixing one half of it to the top soil and the rest spreading on the surface. 1. Pre-decaying of rice straw in limed marine soil promoted the permeability of column soil. but showed a less effectiveness in desalinization of sodium than lime alone or lime plus fresh rice straw treatemenents. 2. Gypsum and calcium carbonate treatments without rice straw fixed Mg in the limed top soil and washed it down disolving more from the layer immediatly be low the treated top soil But the treatment of calcium carbonate and rice straw both together washed out Mg more from lower layers than the upper's, showing only physical desalinization. 3. The desalinization of Na was also severe in the layer immediately below the $CaSO_4$ treated top soil, leauing more Na ilo the top soil, which seemed to be attributed to the peptisation of the top soil and retard peptisation of desalinization when washed the soil applying not enough amount or non of gypsum.

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One dimensional diffusion of NaCl in flooded soil systems (담수(湛水) 토양계(土壤系)에서 염분(鹽分)의 일차원적(一次元的) 확산(擴散))

  • Oh, Yong-Taeg;Yoo, Sun-Ho;Jung, Yeong-Sang;Hong, Chong Woon;Park, Chun Suh
    • Korean Journal of Soil Science and Fertilizer
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    • v.9 no.1
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    • pp.1-8
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    • 1976
  • 1. Under an asumption that Ficks diffusion equation could be applicable in soil systems, the diffusivities of NaCl in several flooded soil systems were measured to range from $0.4{\times}10^{-5}cm^2sec^{-1}$ to $0.83{\times}10^{-5}cm^2sec^{-1}$ 2. It was discussed that, when a polder soil with a uniform initial salt content through the profile is desalinated only by diffusion to flooding water, the salt content in profile is a function of soil depth, diffusion time, and diffusivity as following $$C=C^{\circ}erf\frac{x}{\sqrt[2]{Dt}}$$ 3. On the basis of Kirkham, et al's integration of complementary erra function, the speed of desalting was discussed to be inversely proportional to the square root of time as following $$dq/dt=C^{\circ}{\sqrt{D/{\pi}t}}$$ 4. It was estimated enough to exchange the flooding water once or twice, even when desalination of polder soil is carried out only by diffusion, if the desalination begins in June, the used flooding water is fresh water, and flooding depth is 10cm. 5. Desalination of polder soil by diffusion requires 2 month for good standing of planted rice.

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Changes in Early Stage Vegetation Succession as Affected by Desalinization Process in Dae-Ho Reclaimed Land (대호 간척지의 제염진해에 따른 초기 식생 변화)

  • Lee, Seung-Heon;An, Yeoul;Yoo, Sun-Ho;Lee, Sang-Mo
    • Korean Journal of Environmental Agriculture
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    • v.19 no.4
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    • pp.364-369
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    • 2000
  • In order to obtain the reference data to be used as an vegetation index for degree of desalinization, vegetation successions were surveyed and soil chemical characteristics were analyzed at the naturally maintained plot in Dae-Ho reclaimed land. Seven Groups $(A\;{\sim}\;G\;group)$ were classified as major vegetation; A group (Suaeda asparagoides MAKINO etc.), B group ( Aster tripolium L. etc.), C group (Stearia viridis L. BEAUV), D group ( Phragmites longivalvis STEUD), E group (Limonium tettagonum THUMB A. A. BULLOCK), F group (Trifolium repens L.), G group (Zoysia sinca HANCE etc.). As desalinization process proceeded, the wild vegetation changed in order of $A\;{\to}\;B\;group$, $D\;{\to}\;C\;group$, $E\;{\to}\;F$, G group. Soil texture of the naturally maintained plot was silt loam and soil fertility was very low compared with agricultural cultivated soil. Soil pH ranged from 7.0 to 8.0. Electrical conductivity (ECe) was below 10 and $20\;dS{\cdot}m^{-1}$ at top and subsoil, respectively, except the plot where A group were growing. Resulting from SAR and ECe, The plot where A group was growing was saline-sodic soil and the others were saline soil. The relation between vegetation sucession and soil desalinization showed that vegation appeared under $10\;dS{\cdot}m^{-1}$ of ECe and 15 of SAR except A group.

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Studies on the Desalinization in Reclaimed Tide Lads (II) - by the Open Conduit- (간척지 제염에 관한 시험(II) - 개거에 의한 제염효과 시험-)

  • 정두호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.12 no.3
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    • pp.2029-2034
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    • 1970
  • This research was attempted to study on the effects of desalinization by the depth and interval of open conduit in Kang-Hwa polder where is located at the Kil-sang Myun, Kang-Hwa Gun, Kyung-gi Do, and it has been continued for the three years from 1967 to 1969. The results obtained are as follows; 1. The depths of saline expulsion by supplying of irrigation water are approximately 30cm to 50cm under the ground surface, but saline expulsion is hardly done in case of the depth which is deeper than the above mentioned, because the moisture and saline content hardly change in such a condition. 2. The speed of vertical percolation gradually decreases below the 30cm depth, but it is noticed that there is a tendency to make the percolation of the horizental direction from its layer in Kang-Hwa reclaimed tidal land. 3. Comparing experimental treatments-varing depths and intervals of open conduits, the interval of open conduit has a more effect upon the promotion of desalinization and increasing of the rice yields than the depth of it. Therefore, according to the results of experimental data, the optimum depth of open conduit is about 0.9m, the effective interval of it is about 18m. 4. Considering the loss of arable area by the layout of open conduit, the reasonable interval of it could extend to 36m.

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