• Resources Recycling
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• v.9 no.1
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• pp.27-35
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• 2000

Characteristics of pyrolytic gasification were examined for the waste tire and 7 types of waste synthetic resin, using a bench scale experimental facility. the product gas temperature of waste tires was $150~300^{\circ}C$ and the temperature profile in the combustion zone of the lower reactor part tended to be clearly distinguished from that in the gasification zone of the upper part. However, in the case of waste synthetic resins, there were no clear distinction and temperature fluctuation was severe, depending on the reaction time. Product gas quantity, which depends on that of supplied (1st) air, was found to be 105~135% of the 1st air amount at the steady state. The concentration of noncombustible components in product gas was 80~90 vol.% and the high heating value of the product gas calculated from gas compositions was 1,500~3,000 kcal/N㎥ for waste tire, and 300~2,900 kcal/N㎥ for waste synthetic resins, respectively. Heating value of product gas and combustible gas concentration were increased in proportion to 1st air amount when 1st air amount is below $0.35N\textrm{m}^3$/min.

• Resources Recycling
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• v.31 no.1
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• pp.56-64
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• 2022

Construction waste is generated at a rate of approximately 221,102 tons/day in Korea. In particular, mixed construction waste generates approximately 24,582 tons/day. The other components were recycled by 98.9%. The amount of greenhouse gas emissions from the waste was 17.1 million tons of CO2 equaling 2.3% of the total greenhouse gas emissions. To reduce greenhouse gas emissions, reducing the environmental impact is becoming increasingly important. However, appropriate treatment must first be established, as mixed construction waste is also increasing. Thus, an effective plan is urgently needed because it is frequently segregated and sorted by the landfill and incinerated. In addition, there is an urgent need to prepare various effective recycling methods rather than a simple treatment. Therefore, this study analyzed the environmental impact of the treatment of mixed construction waste by calculating greenhouse gas emissions. As a result, the highest greenhouse gas generation occurred during the incineration stage. Moreover, the optimal method to reduce greenhouse gas emissions is recycling and energy recovery from waste. In addition, the amount of greenhouse gas generated during energy recovery from the waste stage was the second highest. However, greenhouse gas emissions can be reduced by using waste as energy to reduce fossil fuel consumption. In addition, for the transportation stage, the optimal reduction plan is to minimize the amount of greenhouse gas emissions by setting the optimal distance and applying biofuel and electric vehicle operations.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.4
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• pp.537-548
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• 2020

Currently, radioactive waste for disposal has been restricted to low and intermediate level radioactive waste generated during operation of nuclear power plants, and these radioactive wastes were managed and disposed of the 200 L and 320 L of steel drums. However, it is expected that it will be difficult to manage a large amount of decommissioning waste of the Kori unit 1 with the existing drums and transportation containers. Accordingly, the KORAD is currently developing various and large-sized containers for packaging, transportation, and disposal of decommissioning waste. In this study, the radiation exposure doses of workers and the public were evaluated using RADTRAN computational analysis code in case of the domestic on-road transportation of new package and transportation containers under development. The results were compared with the domestic annual dose limit. In addition, the sensitivity of the expected exposure dose according to the change in the leakage rate of radionuclides in the waste packaging was evaluated. As a result of the evaluation, it was confirmed that the exposure dose under normal and accident condition was less than the domestic annual exposure dose limit. However, in the case of a number of loading and unloading operations, working systems should be prepared to reduce the exposure of workers.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.4
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• pp.511-521
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• 2022

Decommissioning of nuclear power plants generates a large amount of radioactive waste in a short period. Moreover, Radioactive waste has various forms including a large volumes of metal, concrete, and solid waste. The disposal of decommissioning waste using 200 L drums is inefficient in terms of economics, work efficiency, and radiation safety. Therefore, The Korea Radioactive Waste Agency is developing large containers for the packaging, transportation, and disposal of decommissioning waste. Assessing disposability considering the characteristics of the radioactive waste and facility, convenience of operation, and safety of workers is necessary. In this study, the exposure dose rate of workers during the disposal of new containers was evaluated using Monte Carlo N-Particle Transport code. Six normal and four abnormal scenarios were derived for the assessment of the dose rate in a near surface disposal facility operation. The results showed that the calculated dose rates in all normal scenarios were lower than the direct exposure dose limitation of workers in the safety analysis report. In abnormal scenarios, the work hours with dose rates below 20 mSv·y^-1 were calculated. The results of this study will be useful in establishing the optimal radiation work conditions.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.111-116
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• 2001

Waste office paper, photocopied or laser printed, has recently increased along with office automatization. In waste office paper, toner ink is used as the printing medium in place of conventional oil ink. Since toner ink cannot be saponificated by alkali and be decolored by bleaching, different from the case of oil ink, toner remains on regenerated paper as black specks. Although cascade recycling of waste office paper is compelled at present, the demand for low-grade paper is limited. From such circumstances, a new separation process for waste office paper is demanded to achieve parallel recycling. At the first stage of separation studies, the sharpness of separation is evaluated using small separators to obtain fundamental data. In a lab-scale separator, the sample amount of one feed is generally a few grams. However, the sample amount used for brightness, ERIC, and image analysis that are generally used to evaluate the efficiency of deinking are not small for lab-scale tests of these analyses. This paper describes an investigation of a sheet preparation method by a small amount of sample under 0.5g and compares the precision of toner content determination of spectroscopic analysis and image analysis from the viewpoint of separation evaluation. The easiness and convenience of the operation using only general-purpose equipments has also been set as a principle purpose. From the viewpoint of an analysis that yields high precision with a small amount of sample in short time, the method calculating the absorption coefficient from diffuse reflectance in the visible region is the most rational method in this study.

• Resources Recycling
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• v.25 no.3
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• pp.43-48
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• 2016

Cement manufacturing plant uses various kinds of industrial/municipal waste. The waste contains considerable amount of potassium, chlorine and small amount of heavy metal. Many researches were performed to fabricate valuable resources from the waste. In this study, various methods, which dissolves and crystallizes potassium/chlorine to extract potassium chloride, were experimented. Especially amount of water, slurry temperature, and stirring time were controlled. Then kind of heavy metal and content of potassium chloride were analyzed. The yield of potassium chloride increased, as the amount of water for slurry increased but it increased slightly, when the water content was over 200%. The yield tended to increase, when the temperature of slurry was over a certain point. The yield did not increase in case of over 10 minutes stirring time. The kind and content of heavy metal in potassium chloride were various according to stirring time. The main heavy metals were Pb, Cu, and $Cr^{6+}$.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.109-109
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• 2022

The global population is increasing every year, and the amount of food waste is also increasing. Direct landfilling of food waste has been prohibited since 2005, and in accordance with the London Convention in 2013, the discharge of livestock manure, sewage sludge, and food waste into the sea is prohibited. In the case of incineration to treat the discharged food waste, the heat point is lowered due to the moisture in the food waste itself, so fuel must be added. Therefore, this study was conducted to get basic data for setting the limit of application by investigating the growth and yield of crops after treating food waste dry powder mixed fertilizer (MF) on red pepper. In the experiment, continuous cultivation was carried out for two years in 2021 (1st year) and 2022 (2nd year). The treatment groups were set as Not Treatment (NT), Chemical Fertilizer (CF), Mixed Fertilizer (MF), Mixed Fertilizer×2 (MF×2). After harvest, crop growth and yield were investigated. As a result of the 1st years of growth survey, CF, MF, MF×2 show significant difference in shoot length compared to NT. About fresh weight and dry weight, CF show significant difference compared to NT. The 2nd years of growth survey, the shoot and root length, fresh weight did not show significant difference with NT. In case of dry weight, MF is significant increased compared to NT. As a result of the yield survey of the 1st year, all treatment groups did not show a significance in yield compared to the NT. In case of 2nd year, all treatment groups show significantly increased value compared to NT. The yield of MF was highest among the treatment groups. In the future, it is thought that it is necessary to quantitatively evaluate the effect of food waste dry powder mixed fertilizer through additional experiments and continuous cultivation, and to establish an appropriate amount of use and establishment of a manual based on this.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.3
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• pp.9-19
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• 2013

This research was performed to make functional papers by using the waste of herbal medicine such as Astragalus membranaceus, Angelica acutiloba, and Artemisia capillaris as additives, and to evaluate their physical and optical properties of the manufactured paper. The physical and optical properties were decreased with the increase of the amount of herbal medicine. Of those manufactured papers, the functional paper with Artemisia capillaris showed the dramatic decrease in its physical properties. Adding the herbal medicine waste as additives developed the aesthetic pattern on the surface of the manufactured paper. The paper showing the black pattern on white surface was most favored. Different patterns could be made by changing the size of fibers and the amount of wastes. There was odor emitted from the paper due to the herbal medicine waste, which make the paper to have a potential for the diverse purpose. The herbal medicine waste can be applied to replace weighting agents in the manufacturing process of paper or used for the fuctional additives, resulting in the reduce of the quantity of a pulp consumed. The paper with 10-20% Angelica acutiloba waste were thought to have the most excellent quality on the process point of view.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.91-100
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• 2004

This study was on a recyling system of food waste using poultry and earthworms. Food waste was fed to the egg-raising hens(Gallus gallus) or ducks(Anas platyrynchos). And the excrement of poultry after ingestion of food waste was mixed with other organic waste such as paper mill sludge or night soil sludge, aged and then provided to the earthworms(Eisenia andrei). An egg-raising hen and a duck ate up 0.40kg and 0.79kg of food waste per day, respectively. And the percental rate of exctretion(the amount of excrement/the amount of food waste eaten up) of an egg-raising hen and a duck was 71.0% and 53.7%, respectively. The excrement of poultry that had been mixed with paper mill sludge and aged was vermicomposted more easily than the excrement that had been mixed with night soil sludge and aged. The excrement of poultry aged for more than 21 days was more suitable to vermicompost than the excrement of poultry aged for less than 21 days. Even though, the earthworm lost its biomass on the mixed feeds regardless of their aging periods, which was supposed to be caused by high salinity in poulty's excrements.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.1
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• pp.19-29
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• 1994

The purpose of this study was to investigate the feasibility of composting of vegetable wastes containing high moisture. The parameters investigated were the effect of energy source addition, difference in bulking agent and recirculation of leachate produced during composting. Laboratory scale composting reactors were used in this study. Chinese cabbages were used as a vegetable waste. Dog food was added to the vegetable waste as a energy source. Wood chips and leaves of platan were used as bulking agents. There may be an appropriate amount of energy source to be added for composting high moisture content vegetable waste. In this study, the appropriate amount of energy source was 20% of the vegetable waste by weight basis. Recirculation of total amount of leachate produced each day on the same day may not be an appropriate approach due to the significant heat-quenching effect. When the total amount of leachate produced was equally devided and recirculated everyday through the whole composting period, the heat-quenching effect was comparatively less significant. There were no notable differences in the temperature profile and the $CO_2$ evoluation rate when leaves were used instead of wood chips as bulking agents. Considering waste recycling, it is desirable to use leaf waste as bulking agents if available, because the leaves are also wastes to be disposed of.