• 한국지반공학회지:지반
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• 제13권2호
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• pp.55-64
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• 1997

계면활성제를 이용하여 홀입자에 흡착된 유기오염물질을 탈착시키는 실험을 실시하였다. 용매로는 중성 세제와 음이온성 세제가 사용되었으며 이를 이용하여 흙으로부터 퀴놀린 및 2-나주들을 분리하였다. 음이온성 세제로 퀴놀린은 약 80%, 2-나푸톨은 90% 가량 탈착되었으며, 중성 세제보다 음이온성 세제가 위의 두 오염물질에 대하여는 덜 효과가 좋은 것으로나타났다. 이온이 제거된 물로 두 오염물질에 대한 탈착실험을 행하여 계면활성제의 탈착능을 물과도 비교하여 보았다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.3-5
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• 2005

The objective of this research was to develop a framework of the Soil Environment Information Management System (SEIMS). In this study, we found that the SEIMS needs to be consisted of three sub-systems (i.e., information input system, DB system, and opening to the public system), which is operated on the Web-GIS basis. Also, we suggested structure and detailed items for each sub-system which are acceptable under the basis of current legal and institutional system. Furthermore, we made several suggestions for future-oriented system. Further researches need to be pursued for developing efficiently the SEIMS, such as 1) DB standards for the SEIMS, 2) guidelines for each cleanup phase, 3) improvement of the SEIMS for groundwater quality, and 4) integrated SEIMS for both soil and groundwater system.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.115-119
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• 2003

Pollutants from industry, mining, agriculture, and other sources have contaminated sediments in many surface water bodies. Sediment contamination poses a severe threat to human health and environment because many toxic contaminants that are barely detectable in the water body can accumulate in sediment at much higher levels, the purpose of this study was to make convenient sampling method and optimal treatment of sediment for water quality improvement in reservoir or stream based on an evaluation of degree of contamination. Results for analysis of S-reservoir sediments were observed that copper concentration of almost areas were higher than the regulation of soil pollution (50 mg/1) for the riverbed. S-stream sediments were observed that copper, arsenic and TPH concentration of almost areas were exceeded soil pollution concerning levels for factorial areas. We used Remscreen(version. 1.0) program which is contaminated soil recovery program to select optimal treatment method of contaminant sediments. The result was shown in the order of Thermal Calcination > Excavation, Retrieval and Off-site Disposal(comparative less then contaminant) > Low Temperature Thermal Desorption + Solidification/Stabilization.

• Geomechanics and Engineering
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• 제4권2호
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• pp.135-150
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• 2012

This paper presents the study of the effect of microorganism Bacillus pasteurii on the properties such as Atterbergs' limit and unconfined compressive strength of cohesive soils. The results of this study reveal that the liquid limit and plasticity index for all clay soils decreased and the unconfined compressive strength increased. Decrease in plasticity index is very high for Kuttanad clay followed by bentonite and laterite. The unconfined compressive strength increased for all the soils. The increase was high for Kuttanad soil and low for laterite soil. After 24 h of treatment the improvement in the soil properties is comparatively less. Besides the specific bacteria selected Bacillus pasteurii, other microorganisms may also be taking part in calcite precipitation thereby causing soil cementation. But the naturally present microorganisms alone cannot work on the calcite precipitation.

• 한국토양비료학회지
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• 제50권5호
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• pp.482-488
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• 2017

The measurement based on reliable standard operating procedures (SOPs) is important for consistent information. The objective of this study is to investigate reliable SOPs of soil physical methods, including core method for bulk density, Yamanaka hardness, and air permeameter method for air permeability. The coefficients of variation in bulk density (core method), Yamanaka hardness, and air permeability were ranged of 1~6%, 8~13%, and 10~84%, respectively. The variation in situ measurement such as bulk density, hardness, and air permeability due to spatial variability at measuring site was larger due to the number of replicates, organic matter content, and soil texture. Nevertheless, air permeability had different values as different number of replicates, and thus, it is thought that more replicates can result in higher reliability. It suggested that investigation of soil physical properties for the target sites should required to consider about soil texture, organic matter content, and number of replications before measurement. In conclusion, core sampling for bulk density measurement in upland soil recommended to perform in 3 repetitions with 2 inch core, and 3 inch core sampling for higher organic matter content.

• 미생물학회지
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• 제7권1호
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• pp.29-40
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• 1969

Two kinds of organic materials, powders of Salicornia and Oryza sativa L. wre added as a source of organic matter to the suspensions of saline soils(soil : water = 1:3) to be 4 per cent of dried saline soil grams. And then, the samples were incubated at $28^{\circ}C$ to improve the decomposition of organic materials by soil microflora. Resutls of this experiment are summarized as followings : 1) The pH of soil suspension showed its highest value on the second or third week after the treatments, which were similar to those of the soil microflora. Results of this experiment are summarized as follwings : 1) The pH of soil suspension showed its highest value on the second ot third week after the treatments, which were similar to those of the soil microflora populations. 2) Salinity increased up to the second week and the highest value of it appeared in the samples which were treated with the powder of Salicornia. In general, the salinity of all samples decreased on the third week after the treatment. The fact was assumed the possibilities of desalination from saline soil by the microbial actions. 3) Soil microflora such as bacteria, actinomycetes and fungi, were determined its populations soil microflora is to act as decomposer in soil. Both of the bacteria and actinomycytes population showed in the third weak after the tratment. In general, 30-years old of saline soil contained microbial population much more than those of 5-year old of saline soil. Salicornia powder favored the increase of both the bacteria and fungal population, and Oryza sativa L. seemed to have been a great role in increase of actinomycetes. Especially, fungal population of the untreated soil suspension contained higher microbial populations more than those of the soils treated with both of the organic materials. 4) Sugar contents of soil suspesions decreased remarkably on the first week after the treatments. 5) The amount of nitrate had similar tendency to those of population changes of soil microflora. Total acidity decreased continuously and the amount of potassium showed its highest value on the third week treatment. However, the amount of phosphorus was determined to be insignificant.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.940-950
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• 2010

In case of uneven surcharge like backfill or embankment after constructing caisson applied on the deep soft marine deposits, lateral deformation of soft soils would happen due to plastic deformation of soil particles by increase of excess pore water pressure. Lateral deformation of soil will result in the caisson displacement which affects soft soil-caisson structure safety. Soft soil was improved by soil compaction pile method, and then gravity caisson was installed. Soil deformations were monitored and analyzed with step by step backfill and embankment behind the caisson. Amount and speed of lateral deformation after the installation of caissons were closely related with the time of backfill and embankment. The relationship between maximum lateral displacement($\Delta_y$) in front of caisson and settlement($\Delta_s$) can be expressed as $\Delta_y=(0.0871)\Delta_s+122.95$. Soft soil depth did not affect the lateral displacement of caisson in this study, which can be explained the soft soil improvement under the caisson by S.C.P. method. Substantially the amount and speed of the lateral deformation of caisson were closely related with the uneven surcharging rate behind caisson.

• Geomechanics and Engineering
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• 제7권6호
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• pp.649-663
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• 2014

In past few years, the use of bacterial calcium carbonate precipitation (biocementation) has become popular as a ground improvement technique for sandy soil. However, this technique was not applied to organic soil. This study focused on bacterial calcium carbonate precipitation and its effect on permeability in organic soil. A special injection system was prepared for inducing bacterial solution to the samples. The bacterial solution supplied to the samples by gravity for 4 days in specific molds designed for this work. Calcite precipitation was observed by monitoring pH value and measuring amount of calcium carbonate. Change in the permeability was measured before and after biocementation. The test results showed that the pH values indicates that the treatment medium is appropriate for calcite precipitation, and amount of precipitated calcium carbonate in organic soil increased about 20% from untreated one. It was also found that the biocementation can be considered as an effective method for reducing permeability of organic soil. The results were supported by Scanning electron microscopy (SEM) analysis and energy-dispersive x-ray (EDX) analysis.

• 한국연초학회지
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• 제21권1호
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• pp.36-48
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• 1999

Field test was conducted in Chungbuk province to evaluate the soil fertility using landscape and soil attributes by application of geographic information system(GIS) in 48 tobacco fields during 2 years(1996 ; 23 fields, 1997 ; 25 fields). The soil fertility factors and fertilizer effects were estimated by twenty five independent variables including 13 chemical properties and 12 GIS databases. Twenty five independent variables were classified by two groups, 15 quantitative indexes and 10 qualitative indexes and were analyzed by multiple linear regression (MLR) of SAS, REG and GLM models. The estimation model for evaluation of soil fertility and fertilizer effect was made by giving the estimate coefficient for each quantitative index and for each group of qualitative index significantly selected by MLR. Estimation for soil fertility factors and fertilizer effects by independent variables was better by MLR than single regression showing gradually improvement by adding chemical properties, quantitative indexes and qualitative indexes of GIS. Consequently, it is assumed that this approach by MLR with quantitative and qualitative indexes was available as an evaluation model of soil fertility and recommendation of optimum fertilization for tobacco field.

• Geomechanics and Engineering
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• 제14권3호
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• pp.301-306
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• 2018

Stabilization of clayey soil has been studied from past to present by mixing different additives to the soil to increase its strength and durability. In recent years, there has been an increasing interest in stabilization of soils with natural pozzolans. Despite this, very few studies have investigated the impact of pozzolanic additives under freeze-thaw cycling. This paper presents the results of an experimental research study on the durability behavior of clayey soils treated with lime and perlite. For this purpose, soil was stabilized with 6% lime content by weight of dry soil (optimum lime ratio of the the soil), perlite was mixed with it in 0%, 5%, 10%, 20%, 25% and 30% proportions. Test specimens were compacted in the laboratory and cured for 7, 28 and 84 days, after which they were tested for unconfined compression tests. In addition to this, they were subjected to 12 closed system freeze-thaw cycles after curing for 28 days. The results show that the addition of perlite as a pozzolanic additive to lime stabilized soil improves the strength and durability. Unconfined compressive strength increases with increased perlite content. The findings indicate that using natural pozzolan which is cheaper than lime, has positive effect in strength and durability of soils and can result cost reduction of stabilization.