• Journal of Soil and Groundwater Environment
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• v.14 no.3
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• pp.47-56
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• 2009

This is a study about how the increase of strength is changed when ground improvement material is mixed with either coastal clay or sandy soil. The ground improvement material was made from mixing a certain proportion of the slag which is by-products generated by smelting the iron ore and the paper fly ash which is formed by bumping up the paper. The ground improvement material was added to coastal soil and sandy soil each. And then according to ratio of water contents, number of curing days and ratio of mixture, specimen for uniaxial compression test was made. The change of uniaxial compression strength and the generated substances was analyzed while the specimen is being cured for 28days. The result of analysis shows that the strength of coastal clay was increased about eleven times more than that of sandy soil. This means that ettringite reaction by ground improvement material becomes more distinctive in the coastal clay than in the sandy soil.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.342-346
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• 2002

불포화 층상 해안 대수층 내에서의 밀도 의존적 지하수 유동 및 염분 이동에 대한 연구를 위해 하나의 지하수 유동-용질 이동 연동 수치 모델이 제시되었다. 이 수치 모델은 밀도 의존적 지하수 유동 지배 방정식, 염분 이동 지배 방정식 및 농도와 밀도의 관계식, 그리고 유한 요소법에 기초하여 개발되었다. 서로 다른 두가지 성질의 불포화 대수층이 고려되었다. 하나는 사질토층 위에 점토층이 존재하는 층상 대수층이고, 다른 하나는 사질토층과 점토층이 혼합된 두가지 물질로 구성된 균질화된 대수층이다. 수치모델의 결과는 층상 불균질성 (layered heterogeneity)가 해안 대수층 내에서의 밀도의존적 지하수 유동과 염분 이동에 있어서 매우 중요한 역할을 하고 있음을 보여준다. 그러한 층상 불균질성의 효과는 사질토층과 점토층과의 현저한 수리학적 및 수리역학적 성질의 차이에 기인한다 따라서 실제 해안 대수층 내에서 관찰되는 점토층을 적절히 고려하는 것이 보다 합리적고 타당한 해안 대수층내에서의 밀도 의존적 지하수 유동 및 염분 이동 해석을 가능하게 할 것이다.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.13-23
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• 2000

The effects of operating condition of soil vapor extraction system and the characteristics of site on the remediation of oil contaminated soil were investigated. Thorough investigation showed that the site was contaminated with gasoline leaked from underground storage tank and the maximum concentration of BTEX and TPH were 1,081 ppm and 5,548 ppm respectively. The leaked gasoline were diffused to 6m deep and the area and volume of the polluted soil were assumed to 170$m^2$ and 1,000$\textrm{m}^3$respectively. The site were consisted of three different vertitical layers, the top reclaimed sandy soil between the earth surface and 3~4m deep, middle silty sand between 3~4m and 6m deep, and the bottom bedrock below the 6m deep. The air pemeability of soil was measured to 1.058-1.077$\times$10$^{-6}$ $\textrm{mm}^2$ by vacuum pump tests. The groundwater which level was 3~4m deep was observed in some areas of this site. The soil vapor extraction system which had 7.5 HP vacuum pump and 8 extraction wells was constructed in this site and operated at 8 hrs/day for 100 days. The BTEX was removed with above 90% efficiency where no groundwater and silty sand were observed. On the contrary, the efficiency of BTEX and TPH were dramatically decreased where groundwater and silty sand were observed. The flow rate of soil air induced by soil vapor extraction system was reduced in deeper soil.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.296-300
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• 1989

This study was carried out to evaluate the effects of clay loam soil, zeolite, and high molecular organic compounds on the improvement of soil physico-chemical properties and soybean yield in a sandy loam soil. Soybean was cultivated from 1987 to 1988. CEC, moisture retention of soil were increased, but soil bulk density and hardness were decreased by soil conditioners. Clay loam soil addition enhanced the soybean yield by 5% at 10ton 10a plot, 7% at 20ton/10a plot. Also zeolite application increased the soybean yield by 6~10%. Effects of soil conditioner application of the 1rst year were greater than that of 2nd year. Some experiments were conducted in laboratory for the effect of soil conditioners on soil physical properties. The nutrient and water holding capacity were highest by K-SAM treatment, but the soil aggregates was most stable by AN-905SH and Primal treatments.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.444-450
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• 2012

The physical and chemical properties of soil in the Mangyeong and Dongjin river basin had been investigated in order to establish the most optimum soil improvement plan on the reclaimed land. The total soil area by reclamation in Saemangeum basin is 113,971 ha. The classification by the distribution of soil series and soil texture is as following. 13 soil series including Chonnam, Buyong and Chonbuk series are period-unknown areas. Regarding the soil texture, they are fine silty ~ clayey very fine. From 1920s to 1960s, Mangyeong, Gwanghwal and Chonbuk series had coarse silty textured soil. After the 1970s, Mangyeong, Gwanghwal, Munpo, Yeompo, Poseung, Gapo and Hasa series have more sandy soil ~ moderately coarse loamy textured soil. Regarding the chemical properties, the concentrations of EC, Exch. $K^+$, $Mg^{2+}$, $Na^+$ and pH are high regardless of the time of reclamation. On the other hand, organic matter (OM) of top soil were 3.3~16.1 g $kg^{-1}$. The organic matter contents were very low though the soil had been farmed for a long time. Furthermore, the deep soil had almost no organic matter with 5.6~1.1 g $kg^{-1}$. The reason is believed that there had not been any movement of OM and clay because pressure or induced pans had been formed by large agricultural machineries and poor vertical drain. Regarding the forming of illuvial horizon (B layer) which tells the development extent of soil, only in the Hwapo reclaimed area where rice had been cultivated for past 90 years, Fe and Mn from top soil are deposited at underground 20~30 cm with 7~8 cm thickness by the movement of clay. It is believed that it had been possible because the earthiness is silty clay loam soil with relatively high content of clay. The soils are soil with concern of damage from sea water, soil on flimsy ground and sandy soil. Therefore, soil improvement for stable crop production can be expected; if the water table would be lowered by subsurface drainage, the water permeability would be enhanced by gypsum and organic matter, and the sandy soil would be replaced by red soil with high content of clay.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.293-302
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• 2008

The limiting factors to determine available soil depth were studied with 390 soil series in soil profile description and physicochemical data in Korean soils. The limiting factors were coarse sandy layer, gravel and skeletal layer, hardpan layer, cat clay layer, poorly drained layer, salt accumulated layer and bed rock layer so on. The soils of having limiting factors were 332 soil series, but soils without limiting factors were 58 soil series. Soils with limiting factors were, hardpan 5, slopeness 93, immature soil 29, cinder 5, sandy 42, gravel or skeletal 47, bedrock 19, high salt content 8, poorly drained soil 22, heavy clay 32, sulfate soil 3 and ash soil 27 etc. And the orders of available soil depth were immature > slopeness > ash > heavy clay > sandy > gravel or skeletal > hardpan > cindery > poorly drained > bedrock > acid sulfate soil > salt accumulated soil etc.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.199-203
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• 2006

In the late growth stage of rice plant, the growth declines even though they grow well in early growth stage. This phenomenon is called autumn declining and it often accompanies the infection of Helminthosporium leaf spot disease. This study was carried out to identify the related environmental factors and to establish the integrated control system of Helminthosporium Leaf Spot Disease in rice. The total area of infected paddy field by Helminthosporium leaf spot was 470 ha in 2000 and 1,004 ha in 2001, which occupied about 1% of the total paddy area in Gyeongbuk province, Korea. The ill-drained sandy paddy occupied 50% of the total area of infected paddy fields and followed by sandy paddy (28%). Comparing the content of soil elements between infected and normal paddy, it was clarified that the organic matter content of normal was higher than that of infected paddy and the contents of inorganic elements such as Mn, Fe, Zn and available $SiO_2$ were also higher in normal paddy. The results of comparing the inorganic elements between infected and normal rice plants also showed the same results. The contents of inorganic elements such as MgO, $SiO_2$, Fe, Mn were higher in normal rice plants. Especially highly significant difference of $SiO_2$ content on both soil and rice plants was noticeable.

• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.109-118
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• 1999

Recently, transport parameters of conservative solutes such as KCl in a porous medium have been successfully determined using time domain reflectometry (TDR) . This study was initiated to Investigate the applicability of TDR technique to monitoring the fate of a heavy metal ion in a sandy soil and the distribution of its concentration along travel distance with time. A column test was conducted in a laboratory that consists of monitoring both resident and flux concentrations of $ZnCl_2$in a sandy soil under a breakthrough condition. A tracer of $ZnCl_2$(10 g/L) was injected onto the top surface of the sample as pulse type as soon as a steady-state condition was achieved. Time-series measurements of resistance and electrical conductivity were performed at 10 cm and 20 cm of distances from the inlet boundary by horizontal-positioning of parallel TDR metallic rods and using an EC-meter for the effluent exiting the bottom boundary respectively. In addition. Zn ions of the effluent were analyzed by ICP-AES. Since the mode and position of concentration detected by TDR and effluent were different, comparison between ICP analysis and TDR-detected concentration was made by predicting flux concentration using CDE model accommodating a decay constant with the transport parameters obtained from the resident concentrations. The experimental results showed that the resident concentration resulted in earlier and higher peak than the flux concentration obtained by EC-meter, implying the homogeneity of the packed sandy soil. A close agreement was found between the predicted from the transport parameters obtained by TDR and the measured $ZnCl_2$concentration. This indicates that TDR technique can also be applied to monitoring heavy metal concentrations in the soil once that a decay constant is obtained for a given soil.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.311-317
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• 1986

This experiment was conducted to find out the minimum size of pores through that Zeolite particles moved vertically out with percolated solution in the sand column and to estimate whether they were lost through the pores in the field sandy soil. The results were as follows. 1. The amount of Zeolite loss through sand columns was increased in the order of the columns filled with $2{\sim}1>1{\sim}0.5>0.5>0.25mm$ sand particles. 2. The Zeolite particles lost through columns filled with $1{\sim}0.5$ and $0.5{\sim}0.25mm$ sand were clay fraction. 3. The pore sire that clay fraction of Zeolite mineral could migrate through was determined to be above $150{\mu}m$ and Jangchon subsoil was presumed to have possibility of Zeolite loss in consideration of its pore size distribution. 4. The suitable particle size of Zeolite for application in sandy soil was presumed to be above $2{\mu}m$.

• Journal of Soil and Groundwater Environment
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• v.18 no.7
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• pp.18-24
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• 2013

The influences of various operating parameters on physico-chemical techniques were evaluated to remediate petroleum-contaminated sandy soil including S/L ratio, kinetic, and effect of soil particle size. The simple extraction using tap water removed only 20.6% of total petroleum hydrocarbon (TPH), and addition of NaOH enhanced the removal of TPH to approximately 30%. To meet the regulation levels, a surfactant, sodium dodecyl sulfate, was added, and the removal of TPH increased to 4 times. Probably, the carbonate minerals affected chemical aging and soprtion of petroleum, which inhibited the extraction of TPH. The soil with smaller particle size contained more TPH, and the removal of TPH was obstructed with smaller particle size. However, NaOH addition increased the removal of TPH in the smaller particles. The physico-chemical properties of soil influenced greatly the removal of petroleum even in sandy soil.