• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.17-25
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• 2020

In this study, non-flammable mineral foam board using waste glass that can be produced to standardized specifications were developed and evaluated for the performance. In addition to the physical and mechanical performance, the environmental properties such as insulation, non-combustibility, gas hazard, sound absorption, etc. were tested to verify the use as interior and exterior building materials. Through the structural review, the validity was verified for the application of the office and restaurant building.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.1
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• pp.213-220
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• 1993

The problem of disposing of huge quantities of used tires is of growing concern to every country. As an economical solid waste management, a gasification followed by incineration process was applied to scrap tires to recover heat and to reduce waste volume for final landfill disposal. The gasification temperature, combustible and non-combustible gasified products and possibly produced air pollutants were predicted by changing equivalent mole ratios of carbon to oxygen by a chemical equilibrium model. For a risk assessment of ash toxic pollutants including heavy metals and toxic organics were thoroughly analyzed. Gasification bottom ash contained much more toxic organic compounds than fly ash, whereas fly ash contained higher concentration of heavy metals such as Pb and Cd. Pretreatment or secure landfill technology is suggested for a safe management of ash produced from the gasification incinerators.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1217-1224
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• 2010

These days, the maintenance of closed waste landfill come to the fore social problem such as legal maintenance period, after closed maintenance deposits, stability evaluation guides and environmental survey for closed landfill management. Therefore the many non-sanitary closed waste landfill has been removed by selection and transfer to sanitary landfill and incineration. When the remove the non-sanitary landfill, the pollution level of bottom soil was investigated by related government law. In this case study, the soil contamination survey was performed to evaluate the pollution level of non-sanitary closed landfill bottom soil. Based on this study, the pollution level of studied non-sanitary landfill bottom soil was content with related government law for third area(factory, parking lot, gas station, road, railroad use etc.).

• Journal of Environmental Health Sciences
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• v.14 no.1
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• pp.63-71
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• 1988

This study is an experimental research on the anaerobic digestion of pig manure and night soil mixed waste at room temperature (25$\circ$C), and the results are shown below: 1. The steady-state condition based on gas production as digestion temperature dropped to 25$\circ$C from 35$\circ$C was achieved at around 28, 47, 56, 64 days respectively when its hydraulic retention time(HRT) are 10, 20, 30, 40 days. 2, Alkalinity and volatile acid(VA) was increased as increasing the organic loading. 3. Removal efficiency of chemical oxygen demand(COD) and biochemical oxygen demand (BOD) was improved as longer HRT, and generally COD value is lower and BOD value is higher relatively. 4. Overall treatment efficiencies of mixed waste are higher than of pig manure and of night soft. 5. Organic removal efficiency at room temperature (25$\circ$C) is 20-25% lower at medium temperature (35$\circ$C) in a same VS loading condition. 6. Refractory fraction of the infiuent VS and organic removal rate constant(K) estimated at around 37% and 0.107/day respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.698-701
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• 2000

To prevent surface and underground water pollution, wastewater treatment is essential. Four bench-scale activated sludge units (10 L operational volumes) were operated at 5, 10 and $20^{\circ}C$ for evaluation of treatment efficiencies with typical wastewater from swine housing. The units were set for a 24-hour cycle. As compared to the conventional process, high removal efficiencies for organic substances, nitrogen and phosphorus in swine wastewater were obtained simultaneously with an intermittent aeration process (lAP). The NOx-N produced during an aeration period was immediately reduced to nitrogen gas (e.g. $N_2$ or $N_2O$) in the subsequent non-aeration periods, and nitrification in aeration periods occurred smoothly. Under these conditions, phosphorus removal occurred with the release of phosphorus during the non-aeration periods followed by the excess uptake of phosphorus in the activated sludge during aeration periods. It was confirmed that the lAP had a better ability to remove pollutants under both low temperatures and high nitrogen loading conditions than the ordinary method did. In addition to that, the total emission of $N_2O$ from lAP was reduced to approximately 1/50 of the conventional process for the same loading. By adopting an adequate aeration programme for individual swine wastewater treatment, this system will provide a promising means for nitrogen and phosphorus control without pH control or addition of methanol.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.474-478
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• 2018

Thermal decomposition of waste Achyranthes Root (WAR) emitted from its decoction process was investigated using a TG analyzer and a fixed-bed reactor. The WAR had the larger C and fixed carbon content than fresh AR (FAR) due to the extraction of hemicelluloses from FAR during decoction process. Thermogravimetric (TG) analysis results also revealed the elimination of hemicellulose by its decoction. Relatively high contents of the cellulose and lignin made high contents of their typical pyrolyzates, such as acids, ketones, furans, and phenols, in the pyrolysis of WAR using the fixed-bed reactor. The increase of pyrolysis temperature from 400 to $500^{\circ}C$ increased yields of oil and gas due to the more effective cracking efficiency of WAR at a higher temperature. The chemical composition of product oil was also changed by applying the higher pyrolysis temperature, which increased the selectivity to furans and phenols.

• Journal of Power System Engineering
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• v.17 no.2
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• pp.87-94
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• 2013

Applicability of organic Rankine cycle for a passenger car with 3.5 L gasoline engine to convert low grade waste heat to useful shaft power has been numerically studied. Working fluid is R134a, and the Rankine cycle is composed of boiler for recovering engine cooling water heat, super heater for recovering exhaust gas heat, scroll expander for converting waste heat to shaft power, condenser for heat emission, internal heat exchanger, and feed pump. Assuming efficiencies of 90% for the heat exchangers, 75% for the scroll expander, and 80% for the feed pump, the Rankine cycle efficiency of 5.53% was calculated at the vehicle speed of 120 km/hr. Net expander shaft output after subtracting the power required to run the pump was 3.22 kW, which was equivalent to 12.1% improvement in fuel consumption. About the same level of improvement in the fuel consumption was obtained over the vehicle speed range of 60 km/hr~120 km/hr.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.2
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• pp.110-118
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• 2014

This paper addresses the fugitive emission factors of Reefer Container at use-phase and disposal-phase. The residual quantities and operation time of thirty nine Container were weighed, using a commercial recover of refrigerants to determine the emission factors at the use-phase. The emission factor at the disposal-phase, refrigerant is accomplished has not recycled, the residual rate was assumed that the emission factor. The average residual rate of thirty nine Container is determined to be $70.8{\pm}4.0%$. The emission factor at the use-phase is estimated to be $4.9{\pm}0.9%/yr$ in the case of using average age of 8.1 years and the average residual rate determined here. We estimate 162.7 g/yr for the average emission quantity of refrigerant per operating Container, while 2038.1 g for that per waste Container. Since the chemical compositions of refrigerant of waste Container were the same as those of new refrigerant, it is expected that the refrigerant recovered from waste Container can be reused for refrigerant.

• Journal of Environmental Impact Assessment
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• v.13 no.3
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• pp.115-124
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• 2004

To utilize a closed municipal solid waste landfill site in environmentally secure conditions, it is necessary to verify the stabilization level of landfill leachate. To assess leachate stabilization of an open-dumping municipal solid waste landfill (Noeun Landfill) which is located at the upper drainage basin of Namhan River which flows into Lake Paldang utilized for Seoul Metropolitan water supplies, the surrounding characteristics of the landfill site was surveyed. After then, leachate, groundwater and soil samples from this landfill were chemically analyzed, and the analysis results were evaluated by "The Criteria of Landfill Waste Stabilization(CLWS)", "Discharge Criteria of Landfill Leachate", "The Criteria of Domestic Use in Groundwater Quality", and "Soil Contamination Criteria" promulgated by Korean Ministry of Environment. The closed open-dumping landfill was equipped with the final soil cover, 3 groundwater monitoring wells and poor landfill gas extraction devices for the post-closure management of the landfill. BOD/CODcr ratios in leachate were less than or slightly higher than 1/10. This results seemed to imply that the leachate stabilization level of this landfill based on the CLWS was almost completed. Qualities of groundwater sampled from monitoring wells located at outside of landfill were adequate for "The Criteria of Domestic Use in Groundwater Quality". Finally, concentrations of soil contaminants that were likely to be influenced by this landfill site were adequate to "Soil Contamination Criteria".

• Resources Recycling
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• v.14 no.1
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• pp.39-46
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• 2005

A solid-state high power torch with inter-electrode insert (IEI) was developed to treat solid waste (for example, incinerated ash), and it's operation characteristics were obtained in the plasma facility test for waste treatment. According to torch test from this study, at the non-transferred mode voltage is increased by gas volume proportionally, and at the transferred mode it is not affected to voltage change. Especially arc voltage is sustained stable at the range of 10% of total Fe in slag. In addition, Electrical conductivity is 0.05~0.25${\Omega}^{-1}cm^{-1}$, torch efficiency is 75~85% and Erosion rate is 2${\times}10^{-6}~6{\times}10^{-6}$ kg/s.