• Journal of the Korean Wood Science and Technology
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• v.41 no.2
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• pp.87-99
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• 2013

Waste paper stands for the major biodegradable organic fraction of most of municipal solid waste. The potential of waste paper for glucose production was investigated in this current work. The pretreatment was accomplished by first subjecting waste paper to disintegration time (30 s), followed by ink removal of disintegrated waste paper using an deinking agent. Concentrated acid hydrolysis of waste paper with sulfuric acid was optimized to maximize glucose conversion. The concentrated acid hydrolysis conditions for waste paper (disintegrated time: 30 s, deinking agent loading : 15 ml) were optimized by using central composite design and response surface methodology. The optimization process employed a central composite design, where the investigated variables were acid concentration (60~80%), loading sulfuric acid (1~5 ml) and reaction time (1~5 h). All the tested variables were identified to have significant effects (p < 0.05) on glucose conversion. The optimum concentrated acid hydrolysis conditions were acid concentration of 70.8%, loading sulfuric acid of 3.2 ml and a reaction time of 3.6 h. This research of concentrated acid hydrolysis was a promising method to improve glucose conversion for waste paper.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.4
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• pp.297-308
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• 2007

The granulation equipment of concentrated wastes is manufactured for the polymer solidification of concentrated wastes. It uses liquid sodium silicate as a granulating agent for the granulating of dried powder containing boric acid. The granulating agent is sprayed in the form of droplet and mean size of dried granules is $2{\sim}4mm$. The new technology which has been used for the polymer solidification of spent resin in U.S. and certified by Nuclear Regulatory Commission (NRC) is successfully applied to concentrated wastes. This uses in-situ solidification process within drum without mechanical mixing. Maximum loading of waste can be achieved without increasing of waste volume. Polymer waste forms were evaluated with several test such as fire test, compressive strength test, leaching test, immersion test, irradiation test, and thermal cycling test according to standard test procedures.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.2
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• pp.143-150
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• 2010

Vitrification technology has been gradually recognized as one of effective solidification methods for concentrated boric acid wastes generated in PWR. Vitrification for low- and intermediate-level radioactive wastes has a large volume reduction and good durability for the final products. A feasibility study for the vitrification of concentrated boric acid wastes has been performed with developing the pre-treatment methods of powdered wastes, glass compositions using glass formulation and demonstration test. The pre-treatment method is pelletizing the powder type for stable feeding within cold crucible melter. The glass compositions should be developed considering molten glass are related with wastes reduction. High contents of sodium and boron within borate wastes give influence to waste loading. A variety of factors obtained from the demonstration test are reviewed, which is wastes feeding rate, off-gas characteristics on stack and glass characteristics of final products such as durability for implementing the wastes disposal requirement. The aim of this paper is to present the feasibility of vitrification and review the solidification method for concentrated boric acid wastes and obtain the physicochemical characteristics of solidified glass.

• Environmental Analysis Health and Toxicology
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• v.4 no.1_2
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• pp.11-17
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• 1989

A quantitative analytical method of highly concentrated PCB is established in the research. With the quantitative analytical method PCB of insulating oil was examined. The following conclusions are derived from this research. 1. The recovery ratio was 95.7% with the quantitative analytical method, which indicates it can be used for the analysis of PCB. 2. PCB concentration of insulation oil in waste condenser was found to be 21.2% thru 13.85% , which was highly concentrated. 3. PCB insulation oil in waste condenser was same as PCB-42.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.220-225
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• 2003

Generally, liquid radioactive wastes generated in nuclear power plant exist in powder form which do not contain moisture through the evaporating process of the Liquid Waste Management System and drying process of the Concentrated Waste Drying System. This powder form wastes are blended homogeneously with paraffin solidification agent and packed in metal drum to ensure its stability during handling and disposal. However, it was experienced that the powder form wastes were not blended homogeneously and separated into two layers in metal drum, on the other hand, a Portion of powder was adhered and solidified to the Inside parts of facility during the blending process. And the flaw of blending process above would come in case the mole ratio of Boron to Sodium in liquid radioactive wastes exceeds 0.2.

• Journal of Environmental Health Sciences
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• v.33 no.1 s.94
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• pp.30-35
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• 2007

Waste policies with waste metering system and recycling in 1995 have contributed to the reduction of solid waste generation. Now rural areas as well as urban areas produce less amount of solid wastes in terms of per capita. However most policies in relation to waste issue have been concentrated in urban areas. Large portion of agricultural waste in rural region are being illegally treated such as open incineration or burned out on the road. In this study, we assessed the atmospheric air quality and health risk by illegal open incineration in rural region. In case of benzene level, worst concentration during illegal open incineration was 0.23 ppm and cancer risk by exposure was estimated to $2.29{\times}10^{-3}$.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.2
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• pp.79-86
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• 2009

Concrete materials in nuclear facilities may become contaminated or activated by various radionuclides through different mechanism. Decommissioning and dismantling of these facilities produce considerable quantities such as concrete structure, rubble. In this paper, the characteristics distribution of the radionuclide have been investigated for the effects of the heating and grinding test for aggregate size such as gravel, sand and paste from decommissioning of the TRIGA MARK II research reactor and uranium conversion plant. The experimental results showed that most of the radionuclide could be removed from the gravel, sand aggregate and concentrated into a paste. Especially, we found that the heating temperature played an important role in separating the radionuclide from the concrete waste. Contamination of concrete is mainly concentrated in the porous paste and not in the dense aggregate such as the gravel and sand. The volume reduction rate could be achieved about 80% of activated concrete waste and about 75% of dismantled concrete waste generated from UCP.

• Economic and Environmental Geology
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• v.12 no.1
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• pp.13-15
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• 1979

Iron ore waste discarded around Choong-ju iron district, Choongchong-Bukdo is as low as 25 per cent of iron, mainly consisting of hematite and magnetite. In this mineral dressing test procedure 93 per cent of magnetite was separated and concentrated into the magnetite concentrate as high as 62 per cent. The remaining sample, mostly, hematite averages about 19.8 per cent of iron which can be concentrated with very good results with the optimum flotation conditioning-pH 3.0 and 3 cc per litre of aero-promoter #845 (0.5% sol.) and 1.5cc per litre of hydro-fluoric acid (40% sol.) and four times of cleaning flotation. Hematite concentrate averages 64.2 per cent of iron. The overall iron concentrate averages 63 per cent of iron with recovery 86 per cent of iron contained.

• Journal of Energy Engineering
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• v.27 no.1
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• pp.76-80
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• 2018

The objective of this research paper is to discuss the waste coffee residue disposal and its environmental effects on the environment. As we know, coffee is one of the most demand and swallowed beverages in the world, which leads to large quantities of solid waste. Which can be toxic and a lot of environmental problems occur. In developing countries, there is a lack of proper coffee waste residue management. The coffee beans and residues contain several organic compounds. The wastewater from coffee industry emitted several pollutants (highly concentrated) and it contaminates the soil, ground waters, aquatic life, and also human health. Hence it is essential to treat the coffee waste residues. Mean while, oyster shell waste and its disposal also a big environmental challenge in the coastal regions of southeast Korea. In this paper, we focused the treatment of coffee waste residue with oyster shell waste powder. Primarily, oyster shells are calcinated at higher temperatures and investigated the calcined CaO powder as an anti microbic agent to the bacteria presented in coffee waste residues. We successfully applied calcium oxide from oyster shell waste, as an antimicrobic agent.

• Journal of Agricultural Extension & Community Development
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• v.10 no.2
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• pp.239-249
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• 2003

Waste policy instruments such as garbage bag-fee system and recycling policy initiated in 1995 have contributed to the reduction of solid waste generation. Rural areas now produce less amount of solid wastes in terms of per capital than urban areas and as compare to a decade ago. However, most policy efforts since the early 1990s related to waste issue have been concentrated in urban areas. Waste problems in rural areas are not the amount itself, but the specific characteristics which are unique in rural regions. Large portion of solid wastes and farming wastes are being illegally treated and/or burned out. Surveys show that the main reasons for the illegal treatment of rural wastes are th lack of systematic policy tools targeting on them, insufficient financial capacity and man power of local governments, rural people's cognition problem about wastes, among others. This study reviews current features of the treatment of rural solid wastes and provides policy suggestions for the resolution of the problem.