• Magazine of the Korean Society of Agricultural Engineers
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• v.14 no.2
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• pp.2593-2602
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• 1972

Plastic pipes Wrapped with synthetic filter are recently used for drainage or Collecting of Underground water. But it's use is possible only for small size of diameter less than 300mm, because large size plastic pipes are not readily availabe. For large diameter infiltration gallery, porous concrete pipes are now used, but it's heavy weight brings difficulties in making, moving and setting of the pipes. With it's conventional method of filter setting, fine sands are brought into the pipes to make trouble to lifting pumps and channels Therefore, initial construction cost and maintenance cost become high. To solve-this problem, new method is developed and tested. Small PVC pipes(diameter 14mm) are assembled at the site of construction to newly devised I beam type circls. The size of circular inpiltration gallery is optionally determined by I beam type circle which support small PVC pipes and is made of PVC amterial. This gallery are wrappd with syntheitc filter to prevent sand instruction. In this test, the diameter of 300, 400, 500mm were used. I beam type circles were made with PVC plated with thickness. t=6, 9, 12mm. Water quantity collected through the PVC circulor gallery are measured and the strengths of the gallery. 1. Allowable setting depth of gallery pipe below graund for the case of t=6mm, D=500mm is 2.72m. 2. Collected water quantity depends on soil texture, depth of water grandient of water surface, filter material angle of setting etc. 3. About 126% of water quantity collected from the one gallery pipe measured in two gallery pipes of two parallel installation.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1478-1486
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• 2009

As a conventional line-fitting method, the Bouwer and Rice method has been popularly adopted to estimate the hydraulic conductivity of an aquifer through a slug test. Because a ventical cutoff wall is usually very compressible and features a small wall thickness, the Bouwer and Rice method should be carefully used for the vertical cutoff wall. In addition, a relatively impermeable layer, called a filter cake, formed at the interface between the cutoff wall and the natural soil formation makes it difficult to use the Bouwer and Rice method directly. In order to overcome such limitations, the original Bouwer and Rice method is modified by incorporating the concept of the flow net method. In this modification, the geometry condition of cutoff walls including the filter cake is effectively considered in evaluating the hydraulic conductivity of a vertical cutoff wall.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E2
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• pp.83-91
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• 2008

This work investigated the methodology to simultaneously optimize the ozone and relative humidity composition for the $NO_x$ degradation using soil biofilter. Experiments were made as a function of inlet ozone concentration ($0{\sim}1,770\;ppb$) and relative humidity ($38{\sim}81%$). Factorial design ($2^2+3$) and response surface methodology by central composite designs were used to examine the role of two factors and optimal response condition on $NO_x$ degradation. It was found that a second-order response surface model can properly interpret the experimental data with an $R^2$-value of 0.9730 and F-value of 71.83, based on which the maximum $NO_x$ degradation was predicted up to 92.8% within our experimental conditions.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.391-394
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• 2003

The applicability of in situ microbial filter or biobarrier technology for the remediation of soil and groundwater contaminated with chlorinated solvents was investigated. The efficiency and rates of reductive dechlorination of chlorinated solvents are known to be highly dependent on hydrogen concentration. In this study, the effect of electron donors on the reductive dechlorination of PCE was investigated using vermicompost (worm casting) and peat as permeable reactive barrier medium The effect of organic acids (lactate, butyrate and benzoate), yeast extract and vitamin $B_{l2}$ on the reductive dechlorination was investigated. Compared to the control (no electron donor added), addition of electron donors stimulated the dechlorinated rate. Among the electron donor treatments, lactate/benzoate amendment exhibited the highest dechlorination rate. Since vermicompost and peat are inexpensive and biodegradable and have high sorption capacity, they could be successfully used as biobarrier media, especially when electron donors (for example, lactate/benzoate) are added.d.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.672-679
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• 2008

During recent years, the large soft ground improvements very rapidly increase with industrial development and it is the types and scales of structure that is enlarged by degree. Then, we must enter construct equipment to improve soft ground and we fulfilled works by carrying out soft clay soil to gain trafficability for them. For improving the soft ground, we lay geotextile on soft clay ground and fill the filter sand that can drain the pore water. Then, we landfill cover soil for come by trafficability of construction tools. Ater that we penetrate vertical drain for dehydration through soft ground. there are very complicated works. For these reason we suggest the methods of soft ground improvement constructions.

• Structural Engineering and Mechanics
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• v.8 no.1
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• pp.53-72
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• 1999

The most important features of linear soil-foundation-structure interaction are reviewed, using stochastic modeling and considering kinematic interaction, inertial interaction, and structural distortion as three separate stages of the dynamic response to the free-field motion. The way in which each of the three dynamic stages modifies the spectral density of the motion is studied, with the emphasis being on interpretation of these results, rather than on the development of new analysis techniques. Structural distortion and inertial interaction analysis are shown to be precisely modeled as linear filtering operations. Kinematic interaction, though, is more complicated, even though it has a filter-like effect on the frequency content of the motion.

• Journal of environmental and Sanitary engineering
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• v.21 no.3 s.61
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• pp.15-26
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• 2006

As traffic in city-centre around the world continues to increase, so levels of atmospheric pollutants continue to rise. High concentrations of NOx can have negative effects on human health, and we must find new ways to reduce their levels in the air we breathe. Nitrogen oxide gas (NOx), consisting of nitrogen monoxide (NO) and nitrogen dioxide $(NO_2)$ produced using $O_3$ oxidation, at a low concentration corresponding to that on roads as a result of exhaust from automobiles, was carried out to evaluate the removal characteristics of NOx through a laboratory-scale biofilter packed with soil as a packing material. A mixture media (yellow soil (30%): soil (40%): compost (10%): a used briquet (20%)) was applied. After about 1day of operation, the removal efficiency for $NO_2$ in all experiments with a constant condition ($25^{\circ}C$ and water humidity (60%)) was over 98%. The retention times of the section between phase I and phase II for formation and reduction of $NO_3$ NO and $NO_2$ on the initial $NO_3$ concentration was 50min $(O_3:195\;ppb),\;55min\;(O_3:925\;ppb),\;65min\;(O_3:1743\;ppb),\;70min\;(O_3:2616\;ppb),\;75min\;(O_3:3500\;ppb)$, respectively The soil biofilter system is a unique technology that purifies urban air by utilizing the natural processes that take place in the soil. Although some of the processes are quite complex, they can broadly be summarized as adsorption onto soil particles, dissolution into soil pore water, and biochemical.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.5
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• pp.21-27
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• 2014

Sediment-laden water is problematic in aquatic ecosystem and for hydraulic structures in a watershed, and agriculture area in a watershed is one of source areas of nonpoint source (NPS), since soil surface typically exposures due to agricultural activities. Especially, severe sediment might flow into stream when agricultural area is located near stream like the Imha-dam watershed. Soil erosion is affected by precipitation, therefore there is a need to consider precipitation characteristics in soil erosion and best management practices (BMPs) simulation. The Web-based Spreadsheet Tool for the Estimation of Pollutant Load (STEPL WEB) allows estimating long-term sediment loads and the impact of best management practices to reduce sediment loads. STEPL WEB and predicted precipitation data by MIROC-ESM model was used to estimate sediment loads and its reduction by filter strip and conversion of agricultural area to forest in the future 30 years. The result indicates that approximately 70 % of agricultural area requires filter strip installation or that approximately 50 % of agricultural area needs to be converted to forest, for 41 % of sediment load reduction.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.187-190
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• 2014

The agricultural policy/Environmental eXtender (APEX) model was developed by the Blackland Research and Extension Center in Temple, Texas. APEX is a flexible and dynamic tool that is capable of simulating a wide array of management practices, cropping systems, and other land uses across a broad range of agricultural landscapes, including whole farms and small watersheds. The model can be configured for novel land management strategies, such as filter strip impacts on pollutant losses from upslope crop fields, vegetated grassed waterways in combination with filter strip impacts, and land application of manure removed from livestock feedlots or waste storage ponds. The APEX model has continually evolved since its inception, and the process of adaptation and modification will likely continue as use of the model expands for an ever-increasing range of environmental problems and conditions. Several improvements to specific model subroutines have already been initiated, while other potential improvements have been identified that will require future research and code modification efforts.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.2
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• pp.137-144
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• 1996

A feasible way to utilize small-scale livestock farm wastewater was explored. In place of common support materials rice straw was employed as a support medium of trickling filter for pig farm wastewater treatment. The straw medium which was humified for 20 days after wastewater treatment and mixed with soil significantly enhanced in general the development of bunching lettuce grown under greenhouse conditions. Improvement of soil chemical properties in terms of fertility was also achieved by the addition of humified straw medium after wastewater treatment. It was found that rice straw served as a satisfactory support medium of trickling filters with the wastewater treatment concerning removals of biological oxygen demand, chemical oxygen demand, and suspended solids.