• Title/Summary/Keyword: Soil standard

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Extraction of Phenol from the Contaminated Soil Using Microwave Energy (Microwave Energy를 이용한 오염토양에서 Phenol의 추출)

  • 이기환;이태호;김윤아
    • Journal of Environmental Science International
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    • v.12 no.4
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    • pp.447-459
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    • 2003
  • This study was carried out to develop an efficient process far the elimination of phenol pollutant from soils. An microwave-assisted process (MAP) and a conventional Soxhlet extraction method (SEM) were employed to extract phenol from two types of soils. The effects of extraction methods, aged time of the spiked soil samples, extraction solvent and extraction time on the extraction performance were compared. Our results demonstrate that the recoveries from standard soil spiked were at least 10% higher fer MAP than these f3r the conventional Soxhlet. The extraction time by MAP requires significantly shelter time (1 min) than 15 h of the conventional Soxhlet. The recoveries from non-contaminated soil spiked with phenol were also almost identical f3r above results. The reduction of the extraction times with efficiency higher than that afforded by the conventional Soxhlet technique supports the suitability of the MAP method.

A Prediction of Degree of Saturation using DIP and Electrical Resistivity (DIP 기법과 전기비저항을 이용한 불포화토의 포화도 예측)

  • Lim, Dong-Ki;Min, Tuk-Ki;Sin, Ho-Sung
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.1177-1181
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    • 2010
  • Unsaturated soil can describe soil particles, air-water and contact face between air and water. The providing a simple method to predict water content in Geotechnical mechanics is very important. In this experiment, DIP (Digital Image Processing) and electrical resistivity techniques were used simultaneously to predict the saturation degree, and the results of two techniques will be compared each other to get conclusion. The experiment was carried out for Jumunjin standard sand. The picture of experimental column of soil and water was taken at different times, then using DIP technique to measure Color number-the height of capillary in soil column. At the same time, measure electrical resistivity of the soil.

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Strength Characteristics of Cement-Mixed Soil (시멘트 혼합토의 강도 특성)

  • Kim, Sang-Chul;Lee, Sang-Ho
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.3
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    • pp.49-56
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    • 2005
  • This study was conducted by the tests of materials engineering and soil mechanics to see the strength characteristics of the ‘Cement-Mixed Soil'. To sum up my experiments, I would like to present the results which are the theoretical base and fundamental data to establish the standard design including the design of mixing proportions of the soil as a construction material. In conclusion, in this study the optimum cement mixing ratio is $9\%$ and in this ratio the optimum moisture content of compaction work is $19.3\%$ from the analysis of the strength characteristics, as well as in consideration of the economic profits and nature familiar facts.

A Study on the effect of slope inclination and rainfall in current cut soil slope design criteria (국내 절토 비탈면 설계기준 적용시 사면경사와 강우조건의 영향 연구)

  • La, You-Sung;Kim, Bum-Joo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1264-1270
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    • 2010
  • In this study, the effects of slope inclination and rainfall on weathered soil slope stability were investigated for current cut soil slope design criteria. A series of slope stability analysis was performed on the slopes with the same height (5m), but different inclinations (1:0.8, 1:1, 1:1.2, 1:1.5, 1:2). Seepage analysis was also conducted to examine the rainfall effects directly and compare the combined seepage and slope stability analysis results with the slope stability analysis results for rainy season from the current cut soil slope design criteria. Typical properties for weathered soils were used in both the slope and seepage analysis. The analysis results showed that, for the slopes much steeper than the standard slopes, the factor of safety criteria were satisfied. Therefore, it appears that the slope designs by current cut soil slope design criteria lead to conservative results.

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Characterization of Humic and Fulvic Acids Extracted at the Soils of Korea and Its DB Establishment (국내 토양 휴믹물질의 특성 규명 및 DB 구축에 대한 연구)

  • 이창훈;유지호;신현상;정근호;이창우
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.04a
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    • pp.397-400
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    • 2003
  • In this study, humic and fulvic acids in soils at the vicinity of domestic atomic power plants(NPPs), located in Yungkwang(YK), Uljin(UJ), Kori(KR), Koseong(KS), Wolseong(WS) area, and in volcanic ash soils of the Cheju island(Mt. Hanla(HL), Manjanggul(MJ)) were isolated, and characterized using chemical(elemental analysis, proton exchange capacity, molecular size distribution) and spectroscopic(UV/Vis., IR, FL, $^{13}$ C NMR spectra) methods. The results were compared with one another and compiled for their DB establishments. The humic substances distribution (humic acid, fulvic acid, Humin) in the soils were also determined by IHSS standard method. Main purpose of this study was to provide a basic data needed to evaluate the effect of humic substances on the migrational behaviour of radioactive elements in contaminated surface soil.

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Study on Characteristics of Soil Compaction using Accelerometer (진동가속도계를 이용한 지반다짐 특성 연구)

  • Chae, Kwang-Seok;Shin, Dong-Hoon;Im, Eun_Sang;Gu, Ja-Duck
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1397-1403
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    • 2008
  • Soil compaction works are essential to construction of dams, breakwaters and roads in order to avoid unexpected settlement/deformation of superstructures. Taking advantage of oscillating accelerometer, this research was made to complement existing methods for assessment of soil stiffness. In order to examine the validity of compaction-degree suggested in the study, tests on vibration characteristics using accelerometers was also performed. Test results for sand and gravel mixtures and Korean standard sands were compared and evaluated by conventional assessment methods under varying conditions as of input frequency, size of loading plate and relative density.

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Studies on the Water Consumption and Growth of Vegetables Cultivated by Hydroponics in' the Green House (시설채소의 수경재배방법별 소비수량과 생육에 관한 연구)

  • 김시원;이경희;김유현;김선주;임창영
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.31 no.1
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    • pp.31-44
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    • 1989
  • In the vinyl house cultivation, the water consumption, evapotnanspirafion ratio, growth condifion by the growing stages and yields of tomato and cucumber were investigated when they cultivated by nutriculture, rice hull charcoal culture and NFF culture. The results obtained are summarized as follows: 1. The mean air temperature in the vinyl house during the experimental perica j was 1.9$^{\circ}$C higher than the outdoor air temperature, the rrnocirnum and minimum air temperature in the vinyl house was 4.6C and 1.7$^{\circ}$C higher than the outdoor temperature, respectively, and the mean daily evaporation in the vinyl house during the experimental period was 4.3rnm that is 02rnrn more than the outdoor evaporation 2. In the tomato cultivation, the growth of rice hull charcoal culture was the best among the three methods, and the growth of NFT culture and nutriculture were worse than the soil cultivation which is standard, and among the nutriculture, the growth of EC 1.3m.mho plot was the best. 3. In the cucumber cultivation, the growth of rice hull charcoal culture was the best, and while the growth condition of NFT culture was worse than the standard soil cultivation, the growth of nutriculture was better than the standard soil cultivation, and the growth of EC 1.3m.mho plot was the highest among the different treatments in the nutriculture. 4. In the tomato cultivation, the total water consumption of rice hull charcoal culture plot was 1107.5rnm which is the highest amount among the three methods, and in the nutriculture, the total water consumption of EC 1.3m.mho plot was 22lAmm which is the highest among the three different treatments. 5. In the cucumber cultivation, the total water consumption of rice hull charcoal culture was 11762rnm which is the highest, and the total water consumption of EC 1.3m.mho plot was 284.9rnm which is more than the 278.9mm of EC 1.Smmho plot and 262.9mm of EC 1.7rnmho plot. 6. The crop coefficient(Kc) of tomato was 0.82 in NFT culture, 4.67 in rice hull charcoar culture and 0.86~0.91 in nutriculture. 7. The crop coefficient(Kc) of cucumber was higher than tomato as 1.13 in NFT culture, 520 in rice hull charcoal culture and 1.08~1.19 in nutriculture. 8. The evapotranspiration ratio in the mid and late season were higher than the beginning and elongation stage, and the average evaportranspiration ratio of tomato and cucumber was 3.81 and 424, respectively, in the rice hull charcoal culture plot. 9. In the tomato cultivation, the total yield per plant of rice bull charcoal culture was 1443.Og which is the highest, and in the nutriculture, their yields were worse because of the damage of downy nidew disease. 10. In the cucumber cultivation, the total yield per plant of rice hull charcoal culture was 1965.7g which is the highest, and while the yield of NFT culture was ahout 25% lower than the stadard soil cultivation, the yield of nutriculture was higher than the standard soil cultivation, and among the treatments in the nutriculture, the yield of EC 1.3m.mho plot was the highest.

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Effects of Split Application of SCB Liquid Fertilizer on Rice Yield and Soil Chemical Property in Honam Plain Field (호남평야지에서 SCB 액비 분시가 쌀 수량과 토양 화학성에 미치는 영향)

  • Lee, Sang-Bok;Cho, Kwang-Min;Yang, Chang-Hu;Oh, Young-Jin;Park, Tai-Il;Kim, Kee-Jong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.2
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    • pp.140-145
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    • 2011
  • In order to establish the application method of slurry composting & biofilteration liquid fertilizer (SCB LF) in rice cultivation, experiments were studied on split application method of it and effects of it on soil chemical properties and rice yields. Land leveling by rotary tillage within 2 days after application of SCB LF, $NH_4$-N concentration in soil was maintained uniformly in all paddy field. Initial concentrations of $NH_4$-N and $NO_3$-N in soil were high at standard fertilization and 100% application of SCB LF as basal fertilization, however, after tillering stage they maintained similar concentrations in all experimental plots. $NO_3$-N content in infiltration water was slightly lower at 70% application of SCB LF as basal fertilization and 30% application of SCB LF as fertilization at panicle initiation stage than at standard fertilization. Yields of rice by split application of SCB LF were lower at 100% application of SCB LF as basal fertilization, however, those of the other application of SCB LF were similar with that of standard fertilization. In case of rice quality, perfect kernel rates were high and protein contents were lower at non-application and 100% application of SCB LF. Rice quality of 70% application of SCB LF as basal fertilization and 30% application of SCB LF as fertilization at panicle initiation stage were similar with that of standard fertilization.

Determination of moisture threshold for solution sampling in different soil texture (토양용액 채취를 위한 토성별 한계수분함량 설정)

  • Lee, Chang Hoon;Kim, Myung Sook;Kong, Myung Seok;Kim, Yoo Hak;Oh, Taek-Keun;Kang, Seong Soo
    • Korean Journal of Agricultural Science
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    • v.41 no.4
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    • pp.399-404
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    • 2014
  • Soil moisture is an important factor for the availability and circulation of nutrients in arable soil. The purpose of this study was to set thresholds moisture content on soil nitrate concentration in the solution for real-time diagnosis. Sandy loam, silt loam, and sandy loam was filled with $1.2g\;cm^{-3}$ at Wagner pots, 0, 100, and $200mg\;L^{-1}$ of $KNO_3$ was saturated. Nitrate in standard solution was recovered about 95% by passing the porous cup. Nitrate concentrations in sampling of soil solution were examined by using a porous cup. The soil solution was higher in accordance with sandy loam> silt loam> clay loam, limited water filled pore space for sampling soil solution was 33.7, 56.4, and 62.2%, respectively. Nitrate concentration in the soil solution was negligible at sandy loam and silt loam during sampling periods, which was decreased about 50~82% in clay loam compared to the initial $NO_3$-N concentration in the saturated $KNO_3$ solution. Over limitation of soil solution sampling, soil EC and $NO_3$-N content were increased with the saturated $NO_3$-N concentration, regardless of soil texture (p<0.05). Conclusively, soil solution by using a porous cup was possible, regardless of the soil texture, which was useful for the diagnosis in nitrate concentration of soil solution. However, because nitrate concentration of soil solution in a clay loam changes, it was necessary for careful attention in order to take advantage for the real-time diagnosis of nitrogen management in soil.

Threshold Subsoil Bulk Density for Optimal Soil Physical Quality in Upland: Inferred Through Parameter Interactions and Crop Growth Inhibition

  • Cho, Hee-Rae;Han, Kyung-Hwa;Zhang, Yong-Seon;Jung, Kang-Ho;Sonn, Yeon-Kyu;Kim, Myeong-Sook;Choi, Seyeong
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.5
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    • pp.548-554
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    • 2016
  • Optimal range of soil physical quality to enhance crop productivity or to improve environmental health is still in dispute for the upland soil. We hypothesized that the optimal range might be established by comparing soil physical parameters and their interactions inhibiting crop growth. The parameter identifying optimal range covered favorable conditions of aeration, permeability and root extension. To establish soil physical standard two experiments were conducted as follows; 1) investigating interactions of bulk density and aeration porosity in the laboratory test and 2) determining effects of soil compaction and deep & conventional tillage on physical properties and crop growth in the field test. The crops were Perilla frutescens, Zea mays L., Solanum tuberosum L. and Secale cereael. The saturated hydraulic conductivity, bulk density from the root depth, root growth and stem length were obtained. Higher bulk density showed lower aeration porosity and hydraulic conductivity, and finer texture had lower threshold bulk density at 10% aeration bulk density. Reduced crop growth by subsoil compaction was higher in silt clay loam compared to other textures. Loam soil had better physical improvement in deep rotary tillage plot. Combined with results of the present studies, the soil physical quality was possibly assessed by bulk density index. Threshold subsoil bulk density as the upper value were $1.55Mg\;m^{-3}$ in sandy loam, $1.50Mg\;m^{-3}$ in loam and $1.45Mg\;m^{-3}$ in silty clay loam for optimal soil physical quality in upland.