• 환경위생공학
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• 제16권1호
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• pp.108-116
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• 2001

It is difficult to task to achieve high biological nutrient removal from municipal wastewater because of low organic content. Volatile fatty acids(VFAs) produced from acid fermentation of food wastes can be utilized as external carbon sources for the biological nutrient process. Significant reduction and stabilization of the food wastes can also be obtained from the acid fermentation. The objective of this study is to evaluate characteristics of acid fermentation of the food wastes. Results obtained from the batch experiment of various organic wastes showed that the food wastes had high potential to be used as an external carbon source because of the largest production of the VFAs with low nitrogen and phosphorus content. The fish waste was found to be the next possible organic waste, while the others such as radish cabbage and molasses waste showed high VFAs consumption potential as a results of high nitrogen and phosphorus content. alkaline hydrolysis of the food waste was carried out using NaOH prior to the acid fermentation. As the alkali addition increased, solubilization of the organics as well as TSS reduction increased. However, fraction of soluble COD to total COD became stable after a sharp increase. Alkali addition greater than 0.5g NaOH per g TS resulted in significant increase in pH.

• 방사성폐기물학회지
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• 제21권2호
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• pp.255-269
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• 2023

Compared to operational wastes, nuclear power plant (NPP) decommissioning wastes are generated in larger quantities within a short time and include diverse types with a wider range of radiation characteristics. Currently used 200 L drums and IP-2 type transport containers are inefficient and restrictive in packaging and transporting decommissioning wastes. Therefore, new packaging and transport containers with greater size, loading weight, and shielding performance have been developed. When transporting radioactive materials, radiological safety should be assessed by reflecting parameters such as the type and quantity of the package, transport route, and transport environment. Thus far, safety evaluations of radioactive waste transport have mainly targeted operational wastes, that have less radioactivity and a smaller amount per transport than decommissioning wastes. Therefore, in this study, the possible radiation effects during the transport from NPP to disposal facilities were evaluated to reflect the characteristics of the newly developed containers and decommissioning wastes. According to the evaluation results, the exposure dose to transport workers, handling workers, and the public was lower than the domestic regulatory limit. In addition, all exposure dose results were confirmed, through sensitivity analysis, to satisfy the evaluation criteria even under circumstances when radioactive materials were released 100% from the container.

• 농촌지도와개발
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• 제10권2호
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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.

• 산업기술연구
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• 제22권B호
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• pp.103-108
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• 2002

This research was performed to investigate the generation and physico-chemical characteristics of municipal solid wastes. The results were as follows: i) The generation rate and bulk density were 0.157 kg/cap/d and 147.8 g/L in residential zone, respectively. In non-residential zone, the generation and bulk density were 1.71 kg/cap/d and 85.6 g/L, respectively. Consequently, bulk density of non-residential zone was lower than that of residential zone. ii) The wastes consisted of 90% of combustibles and 10% of incombustibles in residential zone. And the wastes from non-residential zone was composed 85% of combustibles and 15% of incombustibles. iii) Water content was estimated at 47~50% in residential zone and restaurants. In non-residential zone, except restaurants, water content was in the range of 10~30%. Ash content was nearly 10% in overall zone.

• 한국환경과학회지
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• 제7권3호
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• pp.383-392
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• 1998

Pollution characteristics of leachate and underground soul of the two landfill states were Investigated Domestic wastes were dumped In the two adjacent landfill states. Only small portion of S landifill site was filled with domestic wastes at the first stage of dumping, and most portion of the site was filled with construction wastes. However Y landfill strate was filed with mostly domestic wastes. Higher concentrations of organic pollutants including VOCs were measured In Y landfill site leachate than In S tendon site. Underground souls of the two linam states were analyzed by the two kinds of leaching methods, KEP (Korean Extraction Processl and Acid Digestion. Underground souls of the both landfill states were not polluted by leachates. Underground soils of the two were composed of firie salty material. Thus It Is fecund that fine silty soul layer of the sea shore may be used as a landfillsite.

• 한국환경보건학회지
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• 제18권1호
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• pp.63-68
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• 1992

This study was performed to investigate the seasonal variation of the composition of domestic solid wastes and the characteristics of the leachate sampled in In-Cheon sanitary landfill site. The results were as follows 1. Combustible part was larger than incombustible part of the domestic solid wastes in spring and sumer. 2. The food waste was major source of solid wastes in In-Cheon city as 36.5%, and its variation by seasons was negligible. 3. BOD of the leachate was in the range of 853~7, 350mg/l, and fluctuated by seasons. 4. The mean of COD$_{cr}$ Was 5, 044mg/l, the mean of COD$_{Mn}$ was 2, 212mg/l. Namely, the method by $K_{2}Cr_{2}O_{7}$ was more sensitive than the method by KMnO$_{4}$. 5. TOC was in the range of 773~3, 958mg/l, it was lower than BOD.

• Asian-Australasian Journal of Animal Sciences
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• 제12권4호
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• pp.642-650
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• 1999

Options available for utilization of animal wastes include sources of plant nutrients, feed ingredients for farm animals, substrate for methane generation, and substrate for microbial and insect protein synthesis. The wastes have the most economic value for use as animal feed. Performance of animals fed diets containing animal wastes is similar to that of animals fed conventional diets. Processing of animal wastes to be used as animal feed is necessary for destruction of pathogens, improvement of handling and storage characteristics, and maintenance or enhancement of palatability. Feeding of animal waste has not adversely affected the quality and taste of animal products. In the USA copper toxicity has been reported in sheep fed high-copper poultry litter, but this is not a serious problem with cattle. Potential pathogenic microorganisms in animal wastes are destroyed by processing such as heat treatment, ensiling and deep stacking. Incidents of botulism, caused by Clostridium botulinum, have been reported in cattle in some countries, and this problem was caused by the presence of poultry carcasses in litter. This problem has not occurred in the USA. With appropriate withdrawal, heavy metal, pesticide or medicinal drug accumulation in edible tissues of animals fed animal wastes is not a problem. Feeding of animal wastes is regulated by individual states in the USA. The practice is regulated in Canada, also. With good management, animal wastes can be used safely as animal feed.

• 기술혁신학회지
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• 제2권2호
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• pp.290-308
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• 1999

In this study a system for the treatment or recyling of organic wastes from both urban and rural area was recommended. It was developed based on the resource recovery system regarding human being by four tectnologies; forage, methane production, high-grade composting and complete decomposition. High quality compost can be produced by combining several kind of wastes produced from urban and agricultural areas. High quality compost must possess not only general characteristics of ordinary compost, but also a superior ability to improve the soil properties and must contain more nutrients for plant. Cedar chips were recommended as the main bulking agent to adjust moisture contents and air permeability. Charcoal and zeolite can be used not only as the second bulking agent but also as fertilizer for improve the soil amendment. Complete decomposition of organic wastes is defined by organic matter being completely converted to $CO_2$ and water. All the input water was evaporated by the heat produced through the oxidation of organic matter, In the present study, the complete treatments were successfully achieved for Shochu wastewater, swine wastes, thickened excess sewage sludge, wastes produced by Chinese restaurant and anaerobic digested sludge. First of all, recycling center of organic wastes should be established for the protect the environments and effective recovery of organic resources. This may means the way to derive the recovery of human value.

• 환경위생공학
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• 제20권1호
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• pp.1-11
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• 2005

This research was performed to investigate the generation and physico-chemical characteristics of municipal solid wastes in the east coast of gangwon. The results were as follows: i) The generation rate of G city and Y gun were 0.187-0.384 $\cal{kg/cap/d}$ and 0.136-0.259 $\cal{kg/cap/d}$. Apparent density of G city and Y gun were 137.9-191.9 g/L and 157.3-238.3 g/L, respectively. ii) The wastes consisted of $76.1-97.5\%$ of combustibles and $2.5-23.9\%$ of incombustibles in G city. And the wastes consisted of $73.7-98.6\%$ of combustibles and $1.4-26.3\%$ of incombustibles in Y gun. Most of municipal solid wastes are composed of food, paper, and vinyl-plastics waste. Water content of commercial area, agricultural resident, detached resident, apartment area, school zone were 42.5-45.9, 37.6-43.4, 32.4-38.4, 29.3-32.3, $6.8-26.9\%$, respectively. iii) The low heating value of G city and Y gun were 1,125.5-2,540.7 $\cal{kcal/kg}$, 1,104.4-2,062.3 $\cal{kcal/kg}$, and school and apartment area were higher than commercial area.

• 신재생에너지
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• 제9권1호
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• pp.25-32
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• 2013

It is indispensable to increase the conversion rate of a reducing sugars such as pentose and hexose derived from cellulosic wastes for a highly efficient bioethanol fermentation from food wastes. The saccharification liquid from cellulosic substrates such as vegetable food wastes contained lots of hexose like glucose and pentose like xylose. Since Saccharomyces-based yeasts could not convert xylose to bioethanol, Pichia stipitis which could directly ferment xylose to ethanol was chosen. After selecting Saccharomyces coreanus and P. stipitis, fermentation characteristics by mixture of two yeasts were investigated. As a result, it was verified the production of ethanol was enhanced by the co-fermentation, although there were somewhat differences between the fermentation characteristics by the aeration methods. Moreover, the consumption of pentose, hexose and disaccharide was obviously observed, and aeration in the process of fermentation seemed to stimulate the activity of P. stipitis.