• Journal of Environmental Science International
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• v.8 no.2
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• pp.227-231
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• 1999

This study was conducted to investigate the removal characteristics of $PO_4^{3-}-P$ contained in livestock wastewater using waste concrete. With small particle size, increased dosage and temperature of water, $PO_4^{3-}-P$ was well removed by waste concrete.$PO_4^{3-}-P$ was removed by adsorption reaction in low pH of the primary phase, but the crystallization reaction predominated for increasing pH with passed time. As a result of adapting the adsorption isotherm equation, $PO_4^{3-}-P$ removal was more affected by the crystallization reaction than the adsorption reaction. In the SEM micrograph, there was no evident change on the waste concreter surface. Particle size was plate-phase before reaction but appeared a dense form to progress in the crystallization reaction.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.5
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• pp.114-124
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• 2000

The method to estimate agricultural organic matter flow on the regional scale was established and applied to a rural area in Chongwon-gun, Chungbok in 1996. The study area is of about 67$\textrm{km}^2$ and its population is about 7,000. The stocks and flows of organic matter are represented in dry weight per unit area and dry weight per unit area per year, respectively. the amount of inflow of organic matter indicates a possibility to cause environmental pollution. the amount of animal waste 767 kg/ha/yr account for 42 percent of total amount of organic waste 1,834 kg/ha/yr and therefore the environment in study area is greatly influenced by livestock. The decrease in recycling rate of animal waste form 100% to 70% has greatly increased the amount of disposal waste nearly twice, i.e., from 267 kg/ha/yr to 497kg/ha/yr . The results of this study demonstrate that appropriate animal population, increase in recycling of animal waste and preservation of agricultural land are necessary for environmental conservation of the study area.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.335-335
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.309.2-309
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• 1999

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.310.1-310
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• 1999

• Journal of Environmental Science International
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• v.19 no.2
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• pp.255-260
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• 2010

A stabilization/solidification (S/S) process for lead (Pb) contaminated soils was evaluated using waste cow bone containing apatite like compounds. Soil samples obtained form firing range were treated with waste cow bone. The effectiveness of stabilization was evaluated based on the Korean Standard Leaching Test (KSLT) and soil pH. The leached concentration reduced with increased in dose of waste cow bone. Overall, the KSLT results showed that Pb concentration in soils are significantly affected by amount of waste cow bone. When soil amended with 20 % of waste cow bone, less than 0.1 mg/kg was leached, and soil pH was increased from 6.5 to 8.4. Same results were obtained when finer waste cow bone was applied. The reachable concentration of Pb in soil showed in inversely proportional to solid/liquid ratio. Aging periods indicate improving mix design was applied. Relatively high lead concentrations was observed at the first 1 days, however leaching profile are reduced significantly over time for all mix designs.

• Elastomers and Composites
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• v.35 no.3
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• pp.227-235
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• 2000

This study focused on the recycling technology and application of waste polyurethane scrap($5{\sim}7mm$) and waste urethane form from the footware scrap. Firstly we suggest the waste polyurethane can be used as a component of medium for hydroponic rose culture. Secondly, recycled thermoplastic polyurethane(RTPU) was produced and blended it with high impact polystyrene(HIPS). And also, in order to extend application of recycling field, the former was produced with adding the amine foaming agent to RTPU/HIPS alloy. The main purpose of this study is to diverse of the recycling of the waste polyurethane.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.91-92
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• 2023

With the development of technology, interest in the implementation of free-form buildings is increasing, and research on producing free-form panels is being conducted accordingly. Since free-form buildings are curved and consist of geometric shapes, there are many problems with the production technology of free-form panels that implement them. Due to the inability to reuse molds, the cost of disposal of construction waste and waste of manpower for assembly increase the construction period and construction cost. To improve these limitations, a 3D printed concrete nozzle for FCP production was developed. However, this technology is not quantitatively extruded according to the shape of the panel, and there is a problem that residues are generated. Therefore, an free-form panel extrusion experiment was conducted to analyze the limitations of existing nozzles and to analyze the requirements for the development of new concrete extrusion nozzles. Existing nozzles were unable to be quantitatively extruded, resulting in errors. Due to the weak pressure of the screw and the inability to adjust the internal pressure, detailed extrusion speed control was impossible, and residue generation in the opening and closing device seemed to be the cause. Therefore, a pump capable of quantitative concrete pressure transfer and a pressure control device for easy extrusion of concrete are required. In addition, it is judged that it is necessary to develop an opening and closing device and an extrusion device that do not generate residues. The results of this study are expected to provide information for FCP production and production and to be a basic study of technologies necessary for the production of free-form building panels.

• Journal of the Korean Society of Tobacco Science
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• v.21 no.2
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• pp.136-143
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• 1999

This study was conducted to evaluate the degradation characteristics of waste cigarette filters under 0, 5, 10, and 15cm in depth from soil surface by environmental conditions. Weather was the most important factor during degradation of waste cigarette filters in this study. Bulking of cellulose acetate filaments exposed on soil surface was observed after 2 months, but the form of filter was kept up after 12 months. The treated cigarette filters in soil landfill revealed a little different degradation pattern at each soil landfill depth, The sample in 5cm depth of soil was more degraded then other site. A fluffy appearance of cellulose acetate filaments in the control filter rods was also developed more strongly in soil landfill then on soil surface. From the observation of waste cigarette filters by scanning electron microscopy, much degradation of the fiber of waste cigarette filters could be ascertained in soil landfill. The weight of waste cigarette filters under 5cm from soil surface was reduced about 50%, and the tensile strength of the samples in soil surface and under 5cm from soil surface were reduced 66.0% and 92.4%, respectively. The microbial experiment date that the viable cell number in microbial population and cellulolytic microorganisms showed the maximum values under 5cm from soil surface, suggest that microorganisms in soil play an important roll in the degradation of acetate cigarette filters.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.60-70
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• 2003

The stability of various waste forms to meet waste acceptance criteria was evaluated by using standard test methods of U.S.A and France. Compressive strength of waste forms were above 176.03 kgf/$\textrm{cm}^2$(cement), 15 kgf/$\textrm{cm}^2$(paraffin). In the thermal cycling test, there were no any change in their feature and volume, the loss of weight was 6.15% on the average. In the immersion test for 120 days, the loss of weight of paraffin waste form was 8.85-5.14% pH=3.83. The G-Value of $H_2$ and $CH_4$ in paraffin wax at $10^8rads$ rads of exposure dose were 2.65, 0.016.