• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.192-197
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• 1996

An experimental study was performed to examine the feasibility of using silicic wastes as construction materials for civil structures, and investigate its utility as a replacement for the favored nature resource to prevent the economic loss. In order to achieve this objective, mechnical properties of concrete containing silicic wastes is tested by investigating the strength development through parameters of water-binder ratios replacement 10 percent ratio with respect to curting conditions. The effect of stringth development is investigated for curing conditions when silicic wastes of 10 percent of cement-binder ratios is containde. Comparision on compressive strength of normal concrete and concrete containing silicic wastes at 28 day is conducted. The concrete with silicic wastes have larger compressive strength than of normal concrete by about 20 percent, when cured at 80 degree. The wastes concrete using silica sand shows increased strength, fracture toughness, elastic modulus and strain than the normal concrete, although the silicic wastes concrete could be able to satisfy the generally required strength for conventional concrete structures.

• Journal of Animal Environmental Science
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• v.2 no.1
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• pp.63-78
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• 1996

The main purpose of this research project is to monitor the present state of agricultural environment and to develope the countermeasures for the protection of the environment from the pollution by animal wastes. The results of this research were described largely 3 parts, 1) Monitoring of present state of environmental pollution by animal wastes, 2) Monitoring of animal wastes treatment technology, 3) Strategies for the protection of environmental pollution from animal wastes in future. The current most important problems from animal wastes are water pollution and air pollution commonly regardless of domestic or foreign country. Especially, intensive livestocks breeding pattern in restricted area is actually a real reason of eutrophication, soil acidification, ground water contamination, irrigation water pollution. As a result from this research project, authors recommend the 3 type of strategies for the protection of environmental pollution by animal wastes, 1 . Development of non-discharge type of wastes treatment technology 2. Manufacturing local structure for animal waste recycling system 3. Development of new international environmental program for transfer bioresource and soil environment prevention.

• Hwankyungkyoyuk
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• v.11 no.2
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• pp.130-143
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• 1998

This study was conducted as a preliminary step to establish a model for the practical application of environmental education related to food wastes collected from elementary school foodservices. Methods of treatment and present recycling status of food wastes in elementary schools in Kyonggido were surveyed. The consciousness of dieticians who have been serving for elementary school foodservices was also analyzed through the survey questions concerning environmental education for the reduction and recycling of food wastes. The results derived from this survey were as follows: The major portion of food wastes from elementary school foodservices was constituted with vegetables and soup, and an average amount of food wastes per day was highest in June and July. Therefore environmental education related to reduction of wastes was needed in the first semester of school terms, and the possible reduction of food wastes achieved through the proper planning of school foodservice menu was also needed. In most cases food wastes were collected and treated by animal growing farmers or composted by machines in school. In operating composting machines microorganism inoculant was mostly used but dieticians pointed out the problem of a nasty odor, insects, and high energy consumption. This situation means it has not been operated efficiently and suggests an efficiency problem of machine composting in elementary schools because composting itself is based on the aerobic digestion and high temperature fermentation which kills insects and harmful microorganisms. Elementary school dieticians in Kyonggido were aware that food wastes cause main pollution problem, and that food wastes are valuable resources which can be recycled, and recycling of food wastes is inevitable. But more than half of the schools surveyed have not been reused food wastes in school, so a proper model for recycling and reuse of food wastes in school grounds was thought to be needed. Environmental education programs related to food wastes have not been peformed in more than half of the schools surveyed. It was concluded that the following three plans will be helpful to reduce school food wastes. First, environmental education should be enforced, second, teachers' and dieticians' intensive teaching concerning food wastes should be needed, and finally establishment of a model for recycling and reuse of food wastes in school grounds and its application to environmental education would offer a valuable field experience to school students.

• Environmental Analysis Health and Toxicology
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• v.5 no.1_2
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• pp.51-55
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• 1990

The ultimate Wastes generated after being treated safely and properly were land-filled in Wha Sung Treatment Plant, that of specific hazardous Wastes. There are three kinds of wastes being landfilled, which are sludges, ashes, and solidificated wastes with cement. This research scrutinizes the variations of leachate which originated from landfilled wastes amount to 30,000 ton with analizing the constituent, pH and concentration of wastes once per month since september, 1987. Now, we have some conclusions as followings; 1. The longer retention time of wastes in landfill site and the more quantity of filling-up, the closer pH of leachate to alkalinity. 2. As the quantity of copper and its compounds is over 90 percent of constituents loundfilled wastes, so the copper of leachate goes above treatment criteria. 3. There lis relationship between pH of leachate and eruption of copper and its compounds. The higher pH of leachate, the more secured copper and its compounds. So, we learn that solidificated wastes with cement is more secured than sludges and ashes. 4. The pH and concentration of copper in leachate is low in July and August, this is passing phenomenon which diluted by rainfall in rainy days. 5. The quantities of cadmium and lead of leachate was not over the treatment criteria.

• Journal of Biosystems Engineering
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• v.32 no.5
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• pp.316-323
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• 2007

This study was carried out to obtain the basic data for the development of the solid fuel with investigating the characteristics of mixtures of animal wastes and wasted coal and supply it as an energy resource to agricultural farms for heating of agricultural facilities. It was investigated for the characteristics of animal wastes (swine waste, swine waste with sawdust, cattle waste), wasted coal, the mixtures of animal wastes and wasted coal with or without mixing seawater. The characteristics of solid fuel according to the mixture ratio of animal wastes and wasted coal were analyzed. The effects of seawater affecting on calorific value and thermal pyrolysis of solid fuels were investigated. The results of this study are as follows: 1) The calorific value was improved with mixing seawater into wasted coal due to chemical reaction. 2) The diverse solid fuels of various calorific values can be made with adjusting the ratio of animal wastes and wasted coal. 3) Animal wastes and wasted coal had each different reaction temperature of thermal pyrolysis and the decreasing rate of weight. 4) The mixture of animal wastes and wasted coal would be ignited easily. Therefore, the solid fuel could be ignited more conveniently when seawater is mixed with it.

• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.52-63
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• 2005

Korea has recently implemented two m메or policies on organic wastes, including food wastes. One is the Volume-Based waste Fee System (VBWFS). which went effect nationwide in January 1995, and the other is a ban on the landfill of organic wastes, such as food wastes. organic sludge, and animal manure, in accordance with the Waste Management Act. These two policies have brought about remarkable positive effects, including the reduction of organic wastes at source, and the development of technology for recycling food wastes into feed and compost. However, they have caused obstacles to carry out the policy on food wastes, in areas of legal and technological infrastructures for recycling. Therefore, this study intends to find problems of policies for recycling food wastes, and to suggest ways to resolve them.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1460-1463
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• 2003

In this study, plastic detection technique was developed, applying remote sensing technology as a method to extract plastic wastes, which is one of the big causes of concern contributing to environmental destruction. It is possible to extract areas where plastic (including polypropylene and polyethylene) wastes are prominent, using ASTER data by taking advantage of its absorptive characteristics of ASTER/SWIR bands. The algorithm is applicable to define large industrial wastes disposal sites and areas where plastic greenhouses are concentrated. However, the detection technique with ASTER/SWIR data has some research tasks to be tackled, which includes a partial secretion of reference spectral, depending on some conditions of plastic wastes and a detection error in a region mixed with vegetations and waters. Following results were obtained after making comparisons between several detection methods and plastic wastes in different conditions; (a)'spectral extraction method' was suitable for areas where plastic wastes exist separated from other objects, such as coastal areas where plastic wastes drifted ashore. (single plastic spectral was used as a reference for the 'spectral extraction method') (b)On the other hand, the 'spectral extraction method' was not suitable for sites where plastic wastes are mixed with vegetation and soil. After making comparison of the processing results of a mixed area, it was found that applying both 'separation method' using un-mixing and ‘spectral extraction method’ with NDVI masked is the most appropriate method to extract plastic wastes. Also, we have investigated the possibility of reducing the influence of vegetation and water, using ASTER/TIR, and successfully extracted some places with plastics. As a conclusion, we have summarized the relationship between detection techniques and conditions of plastic wastes and propose the practical application of remote sensing technology to the extraction of plastic wastes.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.71-75
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• 1998

The objective of this study is to investigate geochemical characteristics of mine wastes including tailings in various abandoned mines in Korea. Tailings and wastes were sampled in and around 39 metalliferous mines, and analysed heavy metal concentrations including Cd, Cu, Pb and Zn extracted by 0.1N HCl and aqua regia by Atomic Absorption Spectrometry. Measurements of paste pH and lime requirement were carried out to examine a general geochemical characteristics of the materials. Lots of mine wastes were characterized by very low pH values of 2 to 4 and high lime requirement to control neutralization of the wastes. In addition, elevated levels of heavy metals were found in various mine wastes extracted by both 0.lN HCl and aqua regia. Because the mine wastes can be dispersed into the downstream by clastic movement and wind-blow, it is necessary to control the materials with a proper method for their reclamation.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.208-212
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• 2003

This study was performed to examine the effects of chaff as bulking materials on temperature, pH, weight and volume reduction and salinity in aerobic composting of food wastes. Volume ratios of food wastes to chaff in reactor Control, Ch-1, Ch-2, Ch-3 and Ch-4 were 4:0, 4:1, 4:2, 4:3 and 4:4, respectively. Reactors were operated for 24 days with 1 hour stirring by 1 rpm and 2 hours aeration per day. The lowering of the volume ratio of food wastes to chaff resulted in the ascending of the highest reaction temperature and the elongation of the high temperature reaction period. The lowering of the volume ratio of food wastes to chaff resulted in the more fast time of pH ascending. The lowering of the volume ratio of food wastes to chaff resulted in the more fast consistency in the weight and volume reduction rates. Salinities were condensed by reaction days. The final salinity of Control was 2.79%, and the final range of salinities of chaff mixtures was 2.18 - 2.37%.

• Journal of Environmental Health Sciences
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• v.29 no.4
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• pp.35-41
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• 2003

The objective of this study was investigate the generation rates, composition, proportion and calorific values each of material in the municipal solid wastes as well as the effect of incineration residual leachate on the environment in Yangsan sanitary landfill site. The results were as follows ; The annual average generation rate of municipal solid wastes in Yang-san is approximately 2.0 kg/cㆍd. The weight percent of combustible matters is on average 78∼87% and the lower heating values of municipal solid wastes is measured to be more than 2,151 kcal/kg after removing the briquette component. The food waste was major source of solid wastes in Yang-san city as 35% and its variation by seasons was negligible. Combustible part was larger than incombustible part of the domestic solid wastes in spring and summer. It is recommended that municipal solid wastes be treated by multiple methods such as the sanitary landfill, resources and recovery, composting and incineration.