• Title/Summary/Keyword: Natural soil

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Improvement of Soil Quality for Artificial Planting's Ground with Large Integrated Underground Parking Lot in Apartment Complex (대규모 지하통합주차장을 갖는 공동주택 인공식재지반 토양품질 개선방안)

  • Kang, Myung-Soo;Lee, Eun-Yeob;Lee, Jung-Min;Kim, Mi-Na
    • Land and Housing Review
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    • v.6 no.1
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    • pp.31-39
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    • 2015
  • Most landscape areas in apartment complex have been changing. Increasing the area of underground parking lots have an effect on apartment's circumstance. Natural ground was decreased so that the most space in apartment complex were converted into an artificial ground. To suggest the soil quality management, this study examined the actual situation about the soil quality of planting ground such as the quality standard as artificial soil, the difference of natural ground, and the difference of soil quality according to the work classification. As a result, the soil quality of the apartment complex with a large underground parking lot had low quality of soil. Soil physical properties were relatively fine but soil chemical properties needed the quality control. The soil quality of natural ground and artificial ground was not statistically significant and the soil quality by the work classification also had no statistical significance. Therefore, we established improvements about standards of the chemical properties for quality management, the soil quality in the natural ground and applying the equivalent standard according to the work classification.

Sequestration and Bioavailability of Organopollutants in Soil;Their Implication to the Risk Assessment

  • Chung, Nam-Hyun;Lee, Il-Seok;Song, Hee-Sang;Bang, Won-Gi
    • Korean Journal of Environmental Agriculture
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    • v.19 no.5
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    • pp.442-449
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    • 2000
  • The bioremediation is an economic technology to remove the organopollutants from soil. It is often found that the remediation could not remove the compounds below the levels determined by vigorous extractions as required by regulatory agencies. The reason for the reduced bioavailability with increasing time of aging has been accredited to the sequestration of the compounds in remote sites within or between soil particles. Then, the aging could be defined as the time-dependent sequestration. Partitioning and entrapment have been suggested as mechanism for aging. The rate and extent of the sequestration varies among dissimilar soils. The bioavailability of aged pollutants in soil could be measured by bioassays, mild solvent extraction, and soild-phase extractions. The sequestration could be affected by many factors including various soil properties, wetting and drying cycle, and the presence of cosolutes and NAPLs etc. The bioavailability and sequestration should be considered to determine the environmentally acceptable endpoint.

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대기압의 변화에 따른 휘발성 오염물질의 토양에서 대기로의 거동

  • Choi Ji-Won;Smith James A.;Hwang Gyeong-Yeop
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2005.04a
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    • pp.114-116
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    • 2005
  • Natural attenuation has been actively studied and often selected as final clean-up process in remediation of contaminated ground-water and soil for the last decade. Accordingly, understanding of natural processes affecting the fate and transport of contaminants in the subsurface becomes important for a success of implementation of the natural remediation strategy, Contaminant advection and diffusion processes in the unsaturated zone are naturally related to environmental changes in the atmosphere. The atmospheric pressure changes affecting the transport of contaminants in the subsurface are investigated in this study. Moisture content, trichloroethylene (TCE) concentration, temperature, and pressure variations in the subsurface were measured for the July, August, November, and December 2001 at Picatinny Arsenal, New Jersey. These data were used for a one-phase flow and one-component transport model in simulating the soil-gas flow and accordingly the TCE transport in the subsurface in accordance with the atmosphere pressure variations at the surface. The soil-gas velocities during the sampling periods varied with a magnitude of $10^{-6}\;to\;10^{-7}\;m\;s^{-1}$ at land surface. The TCE advection fluxes at land surface were several orders of magnitude smaller than the TCE diffusion fluxes. A sensitivy analysis indicated that advection fluxes were more sensitive to changes in geo-environmental conditions compared to diffusion fluxes. Of all the parameters investigated in this study, moisture content has the most significant effect on TCE advection and diffusion fluxes.

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Strength Characteristics of the Soil Mixed with a Natural Stabilizer (친환경 토양안정재를 혼합한 지반의 강도특성)

  • Kwon, Youngcheul;Oh, Sewook
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.1
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    • pp.45-51
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    • 2012
  • This article aims to find method to mix a harmless hardening agent and soil generated during construction to make paving materials. The main purpose of this research is to get rid of the harmfulness(Chromium (VI), etc.) of cement which has been generally and frequently used as a hardening agent and strengthen it so that it can be used for the general foundation solidification and stabilization of civil engineering/construction structures such as dredging soil treatment, marine structure foundation treatment, surface soil stabilization, and river bank erosion prevention. NSS(Natural Stabilizer Soil) used for this study takes as its chief ingredient the mixture of lime and staple fibers extracted from natural fibers. It increases the shearing strength of soil that it improves the support and durability of the foundation and prevents flooding and frost as well. The pH measured to know its eco-friendliness was 6.67~7.15, and according to the migration testing, only Pb and CN were lower than the standards, so it can be said that NSS has almost no harmful components in it. According to the result of uniaxial strength testing, when the mixture ratio of weathered soil to NSS was 6%, about 1,850kpa strength was expressed. And according to the result of CBR. testing to figure out its appropriateness as a paving material, the CBR of the foundation was 4%~6%. But when the mixture ratio of NSS is over 6%, the water immersion CBR. is over 100%; thus, it is expected that it will show great utility as a paving material.

Soil Characteristics according to the Geological Condition of Natural Slopes in Busan Area (부산지역 자연사면의 지질조건에 따른 토질특성)

  • Kim, Kyeong-Su
    • The Journal of Engineering Geology
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    • v.17 no.3
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    • pp.471-481
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    • 2007
  • The Landslide in natural slope is occurred mostly by a heavy rain of the summer. This landslide is influenced in soil property of the surface than the rock mass. Soils in natural slope are created by weathering phenomena of the bedrock. These soils differed to the geological conditions such as sedimentary rock, metamorphic rock and volcanic rock. Therefore, estimation of landslide in natural slope is the most important analysis of the bedrock distributions and soil characteristics. This study analyzed the soil property to the natural slopes of Busan area where is distributed to volcanic rock, granite and sedimentary rock. Soil sample conducted various soil tests for estimate the soil physical property and soil engineering characteristics, and analysis of the correlation of geological conditions. In the experiment result, soils were mainly classified by a clayey sand. It is also established that $1.07{\sim}1.99kg/cm^3$ for wet density, $28.2{\sim}39.6^{\circ}$ for angle of shearing resistance, and $8.10{\times}10^{-5}{\sim}8.38{\times}10^{-2}cm/sec$ for coefficient of permeability. From the physical parameter, the soils are estimated to the permeable ground with good shear strength, and soil properties are showed a differential tendency for each geological condition.

A Study on the Correction Factors of Soil Non-linearity Considering Korean Regional Conditions for Seismic Deformation Method Applied to Multi-Utility Tunnels (공동구의 응답변위법 해석 시 국내 특성을 반영한 지반 비선형 보정계수 연구)

  • Choi, Jeong Ho;Yun, Jong Seok;Choo, Yun Wook;Youn, Jun Ung
    • Journal of the Earthquake Engineering Society of Korea
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    • v.25 no.1
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    • pp.11-20
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    • 2021
  • The seismic deformation method is conventionally used as a seismic design for a multi-utility tunnel in Korea. In the seismic deformation method, the soil ground's natural period is one of the most critical factors for calculating the ground displacement using cosine functions. Correction factors for the natural period and shear wave velocity have been used to consider the non-linearity of dynamic soil properties. However, the correction factors have been issued because the correction factors have not been sufficiently studied to consider Korea's regional conditions. This paper aims to evaluate the natural periods for the seismic deformation method considering Korea's ground conditions. Ground response analysis was performed using seven real earthquake records on twelve sites with different soil conditions where actual multi-utility tunnels are installed. As a result, natural periods of the sites were analyzed and new correction factors were proposed according to seismic performance and Korea's regional conditions.

Development of Soil Conditioner Using Wood Decay Fungus and Forest Residue (임지폐잔재와 목재부후균을 이용한 토양개량제의 개발)

  • Min, Kyeong-Heui;Kim, Jae-Young;Yoon, Young-Han;Park, Heon
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.1
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    • pp.61-67
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    • 2006
  • The purpose of this study was to develop soil conditioner using wood decay fungus. The effect of soil conditioner treated with SJ-28 fungus was tested by lettuce cultivation. Cultivating efficiency was investigated by the yield of lettuce. In the plot of soil conditioner treated with SJ-28 fungus (FPG) showed weight of lettuce leaves 4425 g of total yield which was greater than 2434 g shown in the control. Also the numbers of actinomyces and fungi were increased in the plot of soil conditioner treated with SJ-28 fungus (FPG), beneficial for soil. The number of bacteria showed decrease in FPG plot. FPG showed possibility as a soil conditioner.

Natural Regeneration Potential of the Soil Seed Bank of Land Use Types in Ecosystems of Ogun River Watershed

  • Asinwa, Israel Olatunji;Olajuyigbe, Samuel Olalekan
    • Journal of Forest and Environmental Science
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    • v.38 no.3
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    • pp.141-151
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    • 2022
  • Soil seed banks as natural storage of plant seeds play an important role in the maintenance and regeneration of watershed. Natural regeneration potential of the soil seed bank of Land use types (LUTs) in Ogun River watershed (ORW) was investigated. ORW was stratified using proportionate sampling technique into Guinea Savannah (GS), Rainforest (RF) and Swamp Forest (SF) Ecological Zones (EZs). Three LUTs: Natural Forest (NF), Disturbed Forest (DF) and Farmland (FL) were purposively selected in GS: GSNF, GSDF, GSFL; RF: RFNF, RFDF, RFFL and SF: SFNF, SFDF, SFFL, respectively. Systematic line transects was used in the laying of the sample plots. Sample plots of 25 m×25 m were established in alternate positions. Ten 1 m×1 m quadrats were randomly laid for soil core sampling from previously randomly selected ten plots. The core samples (10) were pooled per plot in each LUT and placed in individual trays. Ten trays with sterilized soil were used as control. The trays were watered regularly and checked for seedlings emergence fortnightly for 18 months. The experimental design used was 3×3 factorial experiments. ANOVA, Diversity index (H') and Similarity index (SI) were used to analyze the data. There was significant difference in seedling emergence among ecological zones and land use types (p<0.05). A total of 4,400 seedlings emerged from the soil samples. All species were distributed among 32 families. FL in the RF had the highest number of germinated seeds (705±37.33 seedlings) followed by DF in the RF (701±49.6 seedlings). The lowest emergence was in NF of the SF (199±28.41 seedlings). DF in the RF had highest number of species (34) distributed among 22 families. Emergence from soil seed bank of NF in ORW was generally with more of tree species than herbs that were predominant in FL and DF.

Soil Carbon Dioxide Evolution in Three Deciduous Tree Plantations (3종류 활엽수 조림지 토양의 이산화탄소 발생)

  • Son, Yowhan;Lee, Goo;Hong, Ji-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.27 no.4
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    • pp.290-295
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    • 1994
  • Soil $CO_2$ evolution was measured using the soda-lime method for 20-year-old L. tulipifera, P. albaglandulosa, and Q. rubra plantations planted on a similar soil type in the Kwangneung Experimental Forest during the growing season of 1994. Soil $CO_2$ evolution ranged from $0.21g/m^2/hr$ for Q. rubra to $0.33g/m^2/hr$ for L. tulipifera. and was significantly different among species. We found positive correlations between soil $CO_2$ evolution and air(p<0.001, r=0.39) and soil temperatures(p<0.001, r=0.49). Peaks in seasonal soil $CO_2$ evolution occurred in July and August. Seasonal soil $CO_2$evolution did not necessarily follow changes in air and soil temperatures. This study implies that more work is needed to clarify the influence of other factors on soil $CO_2$evolution.

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Removal of $NH_4-N$ from Synthetic Wastewater Using Soil Column (토양컬럼을 이용한 합성폐수중의 암모니아성질소 제거)

  • Park San Ill;Cheong Kyung Hoon;Kim Hai Yeon;Paik Ke Jin
    • Journal of Environmental Health Sciences
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    • v.31 no.4 s.85
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    • pp.280-286
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    • 2005
  • The purpose of this investigation was to evaluate removal efficiency of $NH_4-N$ using the soil column. Soil, oyster shell and natural zeolite were used as a supporting media of soil column. Removal efficiencies of $NH_4-N$ were $35.9\%,\;41\%\;and\;93.4\%$ for the soil column packed with soil, natural $zeolite(20\%)$ and oyster $shell(20\%)$ at HRT of 72 hours, respectively. The addition of $20\%$ oyster shell to the soil accelerated nitrification in soil column. The influent ammonia nitrogen was mostly converted to nitrate nitrogen in the soil column and little ammonia nitrogen was found in the effluent. When the influent $NH_4-N$ concentration was 200 mg/l, the NIL-N removal was decreased at HRT of 48 hours, while nitrification was significantly increased after mechanical aeration. It was suggested that nitrification from higher $NH_4-N$ concentration was more affected by aeration in soil column process. The number of nitrifiers was approximately in a level of about $10^6\;MPN/g{\cdot}soil$ in the soil column mixed with oyster shell ($20\%$).