• Title/Summary/Keyword: Korean residual soil

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The Effect of Carbon Dioxide Leaked from Geological Storage Site on Soil Fertility: A Study on Artificial Leakage (지중 저장지로부터 누출된 이산화탄소가 토양 비옥도에 미치는 영향: 인위 누출 연구)

  • Baek, Seung Han;Lee, Sang-Woo;Lee, Woo-Chun;Yun, Seong-Taek;Kim, Soon-Oh
    • Economic and Environmental Geology
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    • v.54 no.4
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    • pp.409-425
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    • 2021
  • Carbon dioxide has been known to be a typical greenhouse gas causing global warming, and a number of efforts have been proposed to reduce its concentration in the atmosphere. Among them, carbon dioxide capture and storage (CCS) has been taken into great account to accomplish the target reduction of carbon dioxide. In order to commercialize the CCS, its safety should be secured. In particular, if the stored carbon dioxide is leaked in the arable land, serious problems could come up in terms of crop growth. This study was conducted to investigate the effect of carbon dioxide leaked from storage sites on soil fertility. The leakage of carbon dioxide was simulated using the facility of its artificial injection into soils in the laboratory. Several soil chemical properties, such as pH, cation exchange capacity, electrical conductivity, the concentrations of exchangeable cations, nitrogen (N) (total-N, nitrate-N, and ammonia-N), phosphorus (P) (total-P and available-P), sulfur (S) (total-S and available-S), available-boron (B), and the contents of soil organic matter, were monitored as indicators of soil fertility during the period of artificial injection of carbon dioxide. Two kinds of soils, such as non-cultivated and cultivated soils, were compared in the artificial injection tests, and the latter included maize- and soybean-cultivated soils. The non-cultivated soil (NCS) was sandy soil of 42.6% porosity, the maize-cultivated soil (MCS) and soybean-cultivated soil (SCS) were loamy sand having 46.8% and 48.0% of porosities, respectively. The artificial injection facility had six columns: one was for the control without carbon dioxide injection, and the other five columns were used for the injections tests. Total injection periods for NCS and MCS/SCS were 60 and 70 days, respectively, and artificial rainfall events were simulated using one pore volume after the 12-day injection for the NCS and the 14-day injection for the MCS/SCS. After each rainfall event, the soil fertility indicators were measured for soil and leachate solution, and they were compared before and after the injection of carbon dioxide. The results indicate that the residual concentrations of exchangeable cations, total-N, total-P, the content of soil organic matter, and electrical conductivity were not likely to be affected by the injection of carbon dioxide. However, the residual concentrations of nitrate-N, ammonia-N, available-P, available-S, and available-B tended to decrease after the carbon dioxide injection, indicating that soil fertility might be reduced. Meanwhile, soil pH did not seem to be influenced due to the buffering capacity of soils, but it is speculated that a long-term leakage of carbon dioxide might bring about soil acidification.

Nutritional Factors Affecting Efficiency of a Bioremediation Process for Diesel-Contaminated Soil (경유오염 토양의 생물정화공정에 대한 영양인자의 영향 분석)

  • No, Sang-Cheol;Lee, Cheol-Hyo;Jang, Deok-Jin
    • KSBB Journal
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    • v.14 no.4
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    • pp.503-510
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    • 1999
  • In order to analyze nutritional factors affecting in situ bioremediation of diesel degradation and cell viability were studied by varying nutritional conditions. In column experiments packed with diesel-contaminated soil, nitrogen was found to be the major limiting nutrient. When nitrogen was added to soil at four different levels of C : N (100 : 5, 100 : 10, 100 : 15, and 100 : 20 mg N/kg dry soil), the greatest simulation of microbial activity occurred at the lowest, rather than the highest nitrogen addition. However, no significant effects was observed when phosphorus and air were added. No matter how the incubation mode varied, less than 50% of the diesel was remained after 7 days of treatment, presumably because the residual hydrocarbons were adsorbed on soil particles, adsorption

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Gas Chromatographic Analysis on Residual Concentration and Half-life Time of Cyfluthrin in Potato and Soil (감자와 토양 중에서 Cyfluthrin의 잔류농도와 반감기에 대한 기체 크로마토그래피 분석)

  • Han, Seong Soo;Jeong, Seung Il;Chun, Hyun Ja;Hoang, Geun Chang;Kim, Il Kwang
    • Analytical Science and Technology
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    • v.13 no.6
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    • pp.722-730
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    • 2000
  • The residual concentration and half-life time of synthetic pyrethroid insecticide cyfluthrin in potato and soil were investigated by gas chromatography (GC). The pesticide in potato was extracted with n-hexane, filtered and concentrated. The concentrated phase was transferred to the Sep-Pak silica gel column and purified with acetonitrile and acetone for the analysis by gas chromatography equipped with electron capture detector (GC-ECD). From the standard additional experiments with 0.01 and $0.1{\mu}g$, the recoveries were 85-87% and the detection limit was 0.005 ng. The soil sample was extracted with acetone and dichloromethane. The organic phase was concentrated and redissolved with n-hexane and analyzed with GC-ECD after cleaned with Sep-Pak column. From the standard additional experiments with 0.01 and 0.1 ng, the recoveries were 84-88% and the detection limit was 0.005ng. The half-life time of cyfluthrin in the silty clay was 25 days in the room laboratory and 0.6 days in the fieJd test whereas it was 38 days and 0.5 days for each in case of silty loam.

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Sequential Fractionation of Heavy metals from Mine Tailings and Two Series of Agricultural Soils (광미장과 두개의 농업토양통 토양으로 부터의 중금속의 연속 분획)

  • Chung, Doug-Young;Lee, Do-Kyoung
    • Korean Journal of Soil Science and Fertilizer
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    • v.32 no.4
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    • pp.375-382
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    • 1999
  • In order to investigate the contamination characteristics of the heavy metals in the mine tailings of abandoned gold mine and its surrounding agricultural soils, a sequential extraction procedure of increasing reactivity in the dissolution processes of the heavy metals(Cd, Cu, and Pb) which were associated with solid and/or solution phase in soils was attempted to partition into six particulate fractions : exchangeable, bound to carbonate, bound to Fe-Mn oxides, bound to organic matter, residual, and soluble. Among indigenous heavy metals in the mine tailings, Pb was the most abundant and Cu and Cd were followed by. Fractionation result of Pb obtained from the triplicate samples of the mine tailings were in the order of Fe-Mn oxide> Carbonate> Residual> Organic> Exchangeable> Soluble, while Wolgok series were Exchangeable > Fe-Mn oxide > Carbonate> Organic> Residual> Soluable. However the other heavy metals studied were not followed this trend. The fractionation results of mine tailing and agricultural soils demonstrated that different geochemical fractions were operationally defined by an extraction sequence that generally followed the order of decreasing solubility. Therefore potential mobility and bioavailability of heavy metals as toxic pollution sources can be evaluated when studying the pollution levels of heavy metals in soils.

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A Stud on the Estimation of Leakage and the probing Leakage in the River Bank (하천제방의 누수탐사 및 누수량 평가에 관한 연구)

  • 김경수;조기태
    • Journal of the Korean Society of Groundwater Environment
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    • v.6 no.4
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    • pp.213-217
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    • 1999
  • The river bank is one of the most important structure of fluvial hydraulic structure. Because the breaking of river bank is the cause of calamity, the durability and stability of river bank an very important factors. The breaking of river bank is the cause of the overflow of flood and the leakage of river bank. In this study, we investigated the leakage of river bank using the resistivity probing and estimated the volume of leakage using the weighted residual method The study basin of this study is the upstream of Sumji river basin and the factor of river bank is length 300 m and berm 2.0 m and width 4.5 m and height 4 m. We evaluated the leakage of river basin using using the resistivity probing and estimated the leakage volume using the weighted residual method. The result of this study, the leakage of river bank generated at the point of 39~45 m 80~90 m. 218~222 m. 214~250 m and the type of leakage is the rectangle and the polygon. And the leakage volume of this points evaluated 2.7$\times$$10^{-3}$ $\textrm{m}^3$/sec.

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Evaluation of Residual Tensile Load of Field Ground Anchors Based on Long-Term Measurement (현장 그라운드 앵커 장기거동 분석을 통한 잔존긴장력 평가)

  • Park, Seong-yeol;Lee, Sangrae;Jung, Jonghong;Cho, Wanjei
    • Journal of the Korean Geotechnical Society
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    • v.36 no.8
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    • pp.35-47
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    • 2020
  • For permanent anchors used for slope reinforcement, bearing capacity and durability should be secured during the period of use. However, according to recent domestic and foreign studies, phenomena such as tension fractures, damage to anchorages, deformation and damage to slope and reduction of residual load over time have been reported along the long-term behavior of the anchors. These problems are expected to increase in the future, which will inevitably lead to problems such as increasing maintenance costs and relevant facility collapse. It is necessary to improve maintenance procedures and methods of ground anchors more practically. In this study, the problems and limitations of domestic maintenance methods were analyzed by conducting a literature study, and the measurement data of load cells installed on the install ground anchors were analyzed to determine the change in the residual load with regard to the elapsed date of the anchors. Based on the results, the effect of the construction conditions of anchors and the soil compositions on the increase and decrease of load were identified.

Pollution of Pb in paddy field soil and rice plants at roadside areas;I. Pollution of Pb in paddy field soil and its chemical forms (도로변(道路邊)에 인접(隣接)한 경작지(耕作地) 토양(土壤) 및 작물체중(作物體重)의 연오염(鉛汚染) 제(第)1보(報) 경작지(耕作地) 토양중(土壤中)의 연오염(鉛汚染) 및 화학적(化學的) 형태(形態))

  • Lee, Seog-June;Kim, Jang-Eok
    • Korean Journal of Environmental Agriculture
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    • v.10 no.1
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    • pp.1-10
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    • 1991
  • The object of this stduy was to investigate the pollution of Pb in paddy field soil with different distance from roadside and to find out the relationship between the ratio of chemical fractions of total Pb and soil characteristics. Lead from automobiles is exhausted as particulates composed primarily of halide compounds (PbBrCl, $PbBr_2$, $PbCl_2$). The samples of soil were collected directly from the paddy fields with different distance from the roadside of highway and expressway which are located in Kyungpook province. A sequential extraction procedure was used to fractionate Pb in paddy field soil into the disignated forms of water soluable, exchangeable, organically bounded, carbonate, sulfide, and residual Pb. Results obtained are summerized as follows. 1. The content of Pb in paddy field soil was the highest in Chungdo, 30.0 ppm, the lowest in Koryung, 14.8 ppm, and the total average content was 21.9 ppm. The effect of traffic volume was not clear, but a slight difference according to the order of opened year of roads was showed. 2. The effect of distance from roadside was not clear. The content of Pb in paddy field soil with different distance from roadside was 22.2 ppm within l0m, 22.1 ppm in 10∼30m, 22.2 ppm in 30∼50m. and 21.3 ppm beyond 50m. 3. The distribution of Pb fractions in soil showed a wide difference depending on soil properties. The average content of exchangeable. organically bounded, carbonate, sulfide, and residual Pb was 8.6%, 33.6%, 29.8%, 21.5%, and 6.7%, of total Pb in the soil, respectively. 4. The content of organically bounded Pb in soil showed highly positive correlation with organic matter and CEC, while the content of exchangeable Pb was highly negative correlation. 5. With higher soil organic matter and CEC, organically bounded Pb fraction tend to be higher but exchangeable Pb fraction tend to be lower. Other forms of Pb showed no difference with soil organic matter contend and CEC. The distribution of Pb fraction related to CEC showed similiar tendency with that of organic matter content.

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A Study on Pullout-Resistance Increase in Soil Nailing due to Pressurized Grouting (가압 그라우팅 쏘일네일링의 인발저항력 증가 원인에 관한 연구)

  • Jeong, Kyeong-Han;Park, Sung-Won;Choi, Hang-Seok;Lee, Chung-Won;Lee, In-Mo
    • Journal of the Korean Geotechnical Society
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    • v.24 no.4
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    • pp.101-114
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    • 2008
  • Pressurized grouting is a common technique in geotechnical engineering applications to increase the stiffness and strength of the ground mass and to fill boreholes or void space in a tunnel lining and so on. Recently, the pressurized grouting has been applied to a soil-nailing system which is widely used to improve slope stability. Because interaction between pressurized grouting paste and adjacent ground mass is complicated and difficult to analyze, the soil-nailing design has been empirically performed in most geotechnical applications. The purpose of this study is to analyze the ground behavior induced by pressurized grouting paste with the aid of laboratory model tests. The laboratory tests are carried out for four kinds of granitic residual soils. When injecting pressure is applied to grout, the pressure measured in the adjacent ground initially increases for a while, which behaves in the way of the membrane model. With the lapse of time, the pressure in the adjacent ground decreases down to a value of residual stress because a portion of water in the grouting paste seeps into the adjacent ground. The seepage can be indicated by the fact that the ratio of water/cement in the grouting paste has decreased from a initial value of 50% to around 30% during the test. The reduction of the W/C ratio should cause to harden the grouting paste and increase the stiffness of it, which restricts the rebound of out-moved ground into the original position, and thus increase the in-situ stress by approximately 20% of the injecting pressures. The measured radial deformation of the ground under pressure is in good agreement with the expansion of a cylindrical cavity estimated by the cavity expansion theory. In-situ test revealed that the pullout resistance of a soil nailing with pressurized grouting is about 36% larger than that with regular grouting, caused by grout radius increase, residual stress effect, and/or roughness increase.

A Study of Stability Analysis on Unsaturated Soil Slopes Considering Rainfall (강우를 고려한 불포화 토사사면의 안정해석 연구)

  • Kim, Khi-Woong;Kim, Bum-Joo;Park, Jeong-Jun
    • Journal of the Korean Geosynthetics Society
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    • v.7 no.4
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    • pp.9-18
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    • 2008
  • Shallow slope failures in residual soil during periods of prolonged infiltration are common in Korea. This study examines an infinite slope analysis to estimate the influence of infiltration on surficial stability of slopes by the limit equilibrium method. Approximate method which is based on the Green-Ampt model have been considered to evaluate the likelihood of shallow slope failure which is induced by a particular rainfall event that accounts for the rainfall intensity and duration for various return periods. Pradel & Raad method which is devised to predict the depth of wetting front to decomposed granite soil slopes having measured soil-water characteristic curves. To compare the results with those obtained from the Pradel & Raad method, a series of numerical analysis using SEEP/W were carried out. It was found that the stability analysis of unsaturated soils calculated by using the soil-water characteristic curve of decomposed granite soils was found to be a proper analysis for shallow slope failures due to rainfall.

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The Chemical Properties and Fertilizer Effect of a Residual By-product of Glutamic Acid Fermentation (구르타민 산발효잔사가공물(酸醱酵殘渣加工物)의 성질(性質)과 비효 -II. 토양(土壤)의 이화학적성질(理化學的性質) 개량효과)

  • Hong, Chong Woon;Jung, Yee Geun;Park, Chon Suh;Kim, Yung Sup
    • Korean Journal of Soil Science and Fertilizer
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    • v.6 no.4
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    • pp.227-230
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    • 1973
  • To elucidate the effect of the organic carbon compounds included in a separate from glutamic acid fermentation residue (G. A. F. R) on the improvement of the physico-chemical properties of soil, on a soil low in organic matter content, treated with G. A. F. R and compost, observations on the total organic matter, humic acid, fulvic acid, C. E. C. and the development of aggregates were made. From the results of the investigations it was concluded that, the organic carbon compound in the tested G. A. R. F. is more effective than compost in increasing the total organic matter, humic acid, fulvic acid and C. E. C. of soil and in enhancing the development of soil aggregates.

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