• Journal of environmental and Sanitary engineering
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• v.19 no.4 s.54
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• pp.19-24
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• 2004

The objective of this study was to develop a mechanistically based mathematical model that would consider the interdependence of VOCs transport, microbial activity, and sorptive interactions in a moist, unsaturated soil. Because the focus of the model was on description of natural attenuation, the advective VOCs transport that is induced in engineered remediation processes such as vapor extraction was not considered. The utility of the model was assessed through its ability to describe experimental observations from diffusion experiments using toluene as a representative VOCs in well-defined soil columns that contained a toluene degrading bacterium, Pseudomonas putida G7 md Fl, as the sole active microbial species. The gas-liquid mass-transfer was found to be a key parameter controlling the ability of bacteria to degrade VOCs. This finding indicates that soil size and geometry are likely to be important parameters in assessing the possible success of natural attenuation of VOCs in contaminated unsaturated soils. Therefore we found that Pseudomonas putida G7 and Fl were very effective to remove of refractory pollutants such as toluene in soil by Bio-filter

• Journal of Applied Biological Chemistry
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• v.42 no.3
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• pp.140-145
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• 1999

Livestock manure is generally beneficial to soil and crop production when appropriate amount is applied, but excessive application may be detrimental to soil and water environments. A proper protocol of livestock waste treatment is required to manage the quality of soil and water. A trickling filter system using rice straw media was employed to treat piggery wastewater from small-scaled livestock farms as an alternative to the currently available methods. Batches of piggery wastewater were treated with this system, and the byproducts of rice straw media and trickling filtrate were applied to the soil with cultivating rye (Secale cereale L.). Objective of this research was to characterize these byproducts for the sustainable soil amendments and rye production. Both the treated straw medium and filtrate were proven to be effective organic fertilizers for rye plant development, with the enhanced but balanced absorption of nutrients. The synergistic effects of filtrate in addition to straw application did not show, but the filtrate appeared to lead to a higher water content of the plant. No specific nutrient deficiency or toxicity symptom was shown due to the salts derived from the byproducts applied. Chemical parameters of the soil quality were significantly improved with the application of straw medium either with or without the filtrate. Judging from parameters relating to the salt accumulations, such as sodium adsorption ratio (SAR), electrical conductivity (EC), exchangeable sodium percentage (ESP), potassium adsorption ratio (KAR), and residual P concentrations, the byproducts from piggery wastewater exhibited no detrimental effects on soil quality within the ranges of treatments used. In addition to the effectiveness of the rice straw trickling filter system for the small-scaled swine farms, both rice straw medium and filtrate could be recycled for the sustainable soil amendment and plant nutrition.

• Water Engineering Research
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• v.1 no.3
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• pp.209-222
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• 2000

A spectral formalism was applied to quantify the sampling errors due to spatial and/or temporal gaps in soil moisture measurements. The lack of temporal measurements of the two-dimensional soil moisture field makes it difficult to compute the spectra directly from observed records. Therefore, the space-time soil moisture spectra derived by stochastic models of rainfall and soil moisture was used in their record. Parameters for both models were tuned with Southern Great Plains Hydrology Experiment(SGP'97) data and the Oklahoma Mesonet data. The structure of soil moisture data is discrete in space and time. A design filter was developed to compute the sampling errors for discrete measurements in space and time. This filter has the advantage in its general form applicable for all kinds of sampling designs. Sampling errors of the soil moisture estimation during the SGP'97 Hydrology Experiment period were estimated. The sampling errors for various sampling designs such as satedlite over pass and point measurement ground probe were estimated under the climate condition between June and August 1997 and soil properties of the SGP'97 experimental area. The ground truth design was evaluated to 25km and 50km spatial gap and the temporal gap from zero to 5 days.

• Journal of Korean Society on Water Environment
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• v.33 no.4
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• pp.474-480
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• 2017

This study was to estimate the reduction effect of nonpoint source pollutants according to the rainfall intensity and drainage of infiltration grate inlet. Soil infiltration flow was measured on-site and SS load by the filter part was calculated by the experimental data in laboratory reactor test. Soil infiltration flow was measured to be about $1m^3/hr$ in soil condition saturated with water. The filter part of the infiltration grate inlet was a hydraulic equipment unhindered by soil infiltration on the bottom of the storage tank, because the infiltration flow was measured to be about $3m^3/hr$ continuously in the closing infiltration hole condition. Infiltration flow and SS load were over about $1m^3/hr$ and 1.71 kg according to laboratory results by the filter part using the artifical sample. Therefore, the above values could be presented as the limitted value to start the reduction of filtration effect. Reduction efficiencies of SS load by the filter part for the rainfall intensity were about 87 % at 5 mm/hr and about 61 % at 10 mm/hr in consideration of one infiltration grate inlet got the drainage area about $200m^2$. The reduction efficiency of nonpoint source pollutants was very effective in the first flush rainfall. However, the reduction efficiency by rainfall density was higher than by flow.

• The Korean Journal of Soil Zoology
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• v.1 no.2
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• pp.81-88
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• 1996

Entomopathogenic nematodes, Steinernema carpocapsae, was able to invade and kill the several lepidopteran pests including the beet armyworm, Spodeptera exigua Hubner, which was the most effective target host. The beet armyworms treated with the effective nematode concentrations were died within 48 hrs. The lethal effect of the nematode was varied among the developmental stages of the host. The fifth instar larvae of the beet armyworm was more vulnerable to the nematode than the third instar larvae. Pupae was, however, refractory to the nematode. All three bioessays (topical application, filter paper test, and soil treatment) showed the positive correlation between the number of the treated nematodes and the mortality of the host. Topical application was the most effective and fast-acting method so that it gave the lethal effect 2 days earlier than did filter paper test at the same number of the treated nematodes. Soil treatment required higher number of the nematodes to get the effective lethality than did filter paper test. The fifth instar larvae of the beet armyworm expressed the specific hemolymph proteins of 5 to 10 kDa in response to nematode infection.

• Journal of the Korean Geosynthetics Society
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• v.19 no.4
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• pp.85-93
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• 2020

This study describes the results of laboratory model test on settlement of soil contaminated with heavy metals, in order to evaluate the applicability of VMS to the measurement of gound settlements generated during the purification of contaminated soil. The measurement results for settlement of contaminated soil were compared using a 3D-Visual Monitoring System (VMS) based on digital photogrammetry and a total station. The test result showed that the settlement of the soil contaminated with heavy metals occurred a lot in the experimental condition in which the hydrophilic filter was applied. The minimum and maximum error ranges of VMS were calculated as ±0.36mm and ±0.87mm, respectively, and the error of VMS was satisfied in all experimental conditions. The average error rate of VMS was lower in the hydrophilic filter condition than in the hydrophobic filter condition. Therefore, it was evaluated that VMS can be applied to measure the settlement of contaminated soil.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.135-144
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• 2010

This study was performed to suggest a soil loss reduction skill through estimating soil erosion from a small watershed including each type of sloping agriland by using GEOWEPP model. Experimental watershed at Gangwon province was selected for very typical sloping fields of highland agriculture in Alpine area. Runoff discharge and sediment load, hourly rainfall amount occurred during storm event were gauged, and weather data were obtained from Daegwallyeong meteorological station. The results of GEOWEPP model estimation showed that relative error values for total runoff discharge and sediment load were 3 %, -14.5 % respectively. Based on the result, soil erosion and waterway path map for each hillslope were made to select target hillslope. Several hillslopes of severe soil erosion were analyezed and then the optimal vegetative filter strip construction width and waterway path to plant grass were decided by using GEOWEPP Model.

• Journal of the Korean Geotechnical Society
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• v.16 no.4
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• pp.107-116
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• 2000

In this study, the permeability reduction in the soil-filter systems due to clogging phenomenon was evaluated. An extensive research program was performed using two typical weathered residual soils which were sampled at Shinnae-dong and Poi-dong area in Seoul. Two separate simulation tests with weathered residual soil were performed: one was the filtration test(cross-plane flow test); and the other was the drainage material in the field. The compatibility of the sol-filter system was investigated with emphasis on the clogging phenomenon. The hydraulic behaviour of the soil-filter system was evaluated by changing several testing conditions. Also, experimental results of the permeability reduction are compared with the results obtained from the theoretical model which can monitor the spatial variation of the permeability with time.

• Journal of Life Science
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• v.22 no.6
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• pp.723-729
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• 2012

Filter plate microbial trap (FPMT) was invented as an in situ cultivation device for the isolation of bacteria from natural environments. FPMT consists of a medium and membrane filters (0.45 ${\mu}m$ pore size) and microorganisms and compounds can be moved freely moved into the medium. This device was applied to two soil samples of Greenland. The microbial diversity of both soil samples by FPMT was higher than that by the conventional Petri dish-based method. Moreover, novel bacterial species were isolated by FPMT. The new FPMT is effective for in situ cultivation of natural samples and could be applicable to the isolation of uncultivable microorganism.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.599-615
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• 2022

In order to excavate underground tunnel most safely such as Han river, the slurry shield TBM method is applied to cope with face of high water pressure for many metro projects. In downtown subway project most of excavated soil is discharged externally whereas in road construction excavated soil is used as filling materials so it becomes important factor for success of the project. After excavated soil, weathered rock and soft rock are discharged with bentonite through discharge pipe to slurry treatment plant then those soils are separated in separation plant according to those size. Fine grained soil has been discarded together with filter cake but it is not toxic and can be mixed with coarse aggregate in proper ratio so this study is performed to find use of qualified filling material to meet quality standard. Therefore, in this study, legal standards and quality standards for the utilization of excavated soil of the slurry shield TBM method were examined and test was conducted to derive recycling way for filter cake and aggregate. And a plan for using it as a filling material for road construction was derived. Because bentonite is a clay composed of montmorillonite, and the excavated soil in the tunnel is also non-toxic, disposal of this material can waste social cost so it is expected to be helpful in the underground space development project that carries out the TBM project by recycling it as a valuable resource.