• Journal of environmental and Sanitary engineering
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• v.22 no.2
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• pp.21-33
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• 2007

The purpose of this study was to evaluate the consciousness and behavior for environmental problems of university student and the necessity of schooling for environmental education. In order to achieve this purpose, a method of questionnaire was administered to total 1012 students selected from 5 universities in Suwon Si etc.. The results in questionnaire were as follows. Most students responded that living environmental education in middle and high school was helpful(70.4%) in practical living. And the most serious problem of living environmental pollution was water pollution(53.6%), air pollution(19.8%), waste material pollution(15.8%), food additives(7.9%), genetic modified organism(3.0%), respectively. And students obtained most knowledge of living environmental problems in internet(87.0%). Also most students responded that the main source and cause of water pollution and air pollution was industrial waste 63.4%, vehicles 61.5%, respectively. And level of environmental behaviors and consciousness of students distributed by major was science & engineering 2.13/4, etc. 2.08/4, art & athletics 1.6/4, liberal art 1.53/4, respectively. And also most respondents have recognition the necessity of schooling for environmental education.

• Journal of Biosystems Engineering
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• v.35 no.5
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• pp.336-342
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• 2010

This study was performed to develop extrusion pelletizer for pelletizing the compost waste food. The effect of water content on the shape of pellet, the relationship between diameter of pellet and of extrusion hole and the relationship between extrusion force and die angle were investigated. Considering the stable shape of compost pellet and the operation efficiency of pelletizer, the water content of 2~4% was considered as the best condition. And the compost pellet could not maintain it's shape at the water content of 10% or over. The strongest extrusion force was needs when the die angle had $90^{\circ}C$ in 6 mm extrusion hole diameter, on the other hand, the weakest extrusion force was need at the die angle of $45^{\circ}{\sim}65^{\circ}$. The compression strength of pellet shows the highest strength of 9.2Mpa when we make the compost pellet after screening the compost and make it with a size of 1.18 mm(No.16) or less.

• Environmental Analysis Health and Toxicology
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• v.14 no.4
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• pp.165-174
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• 1999

This study was conducted to analyze the priority of environmental problems in Korea by investigating the environmental professionals' perception. The delphi technique was applied to identify their risk perception towards some specific items related with pollution. A standardized questionnaire on environmental problems and their priorities was used to 74 subjects. In the questionnaire, the environmental problems were divided into the general ones,9 items, and the specific ones,30 items. Also, the perception was associated with two points of view which were the risk on general human health or ecosystem, and on the present situation in Korea. The priority of risk from general environmental problems on human health or ecosystem was analyzed in the order of 'water pollution', 'air pollution', 'soil contamination', 'waste', 'toxic chemical pollutants', 'food contamination', 'ocean contamination', 'odor pollution', and 'noise pollution'. The priority of risk on the present situation in Korea was analyzed in the order of 'water pollution','air pollution','waste','toxic chemical pollutants','food contamination','soil contamination','ocean contamination','odor pollution', and 'noise pollution'. And these priorities were significantly related with the characteristics of respondents such as sex, age, and major concerned area. However, for the first five priorities of risk from the specific environmental problems on human health or ecosystem, the environmental professionals agreed with 'automotive vehicle exhaust', 'domestic and industrial source pollutants to surface water', '$CO_2$nd g1oba1 warming effect','toxic air pollutant' and 'industrial source air pollution'. The priorities of risk on the present situation in Korea were similar to these results.

• Journal of the Korean Applied Science and Technology
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• v.29 no.4
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• pp.653-658
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• 2012

There is an increasing interest in the use of electrochemical methods for the food waste treatment. The technologies using the electrochemical method provide ideal tools for approaching industrial and food wastes problems. Unlike other chemical treatments, the electrochemical systems do not make the volume of the secondary waste increase. The electrochemical methods can be operated with electrochemical apparatus and inorganic agent allow selective separation and recovery and even quieter than others. This study concerns design factors, electrode construction and wastewater treatment process of the electrochemical apparatus. The experiment of color, COD and BOD removal is much effective in using electrochemical method with ultrasonication and ozonation.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.29-37
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• 2008

In this work, it was investigated that various aspects of process, application situation, merits and short-coming results of the thermophilic methane fermentation with highly concentrated organic waste substances such as sewage sludges, food wastes and excretions. The merits of this methane fermentation were that it had a very fast reaction rate and was possible to proceed in high loads. It was also high in mortality for pathogenic microorganism and the digested sludge was more hygienic. However, the short-comings were that more energy was required for heating in the fermentation facility, no surplus energy could be gained from low concentration of organic waste, the fermentation treatment dropped level of water quality, thus burdens discharging process of water. Especially, the high concentration of methane fermentation could possibly lack nutritious salt and could face the disturbance by ${NH_4}^+-N$, a proper alternative was required. In general, thermophilic methane fermentation was considered as a better mean in disposing of cow excretion and food waste which were highly concentrated organic wastes. On the other hand, under the condition where the concentration of waste material was low and the high concentrate waste material became higher than 3,000 mg/L in ${NH_4}^+-N$, thermophilic methane fermentation resulted less desirable outcome.

• Journal of the Korean GEO-environmental Society
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• v.15 no.9
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• pp.13-18
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• 2014

BMP test was carried out to evaluate the characteristics for co-digestion of night soil and food waste. 6 types of sludge were tested in 30 days which were raw, excess, digested, night soil/septic tank (1:1), food waste (food : dilution water = 1:1), and mixed sludge. Bio gas was produced actively after 2 days, and continued in 2 weeks. Gas generation amount was decreased rapidly after considerable space of time. Especially maximum productivity of gas was shown in 7~8 days. The ultimate methane yields of raw, excess, digested, night soil/septic tank, food waste, and mixed sludge were 64.63, 67.49, 66.45, 72.44, 107.85, and 46.71 mL $CH_4/g$ VS respectively from Modified Gompertz model. The lag growth phase time and maximum specific methane production rate of mixed sludge were 1.88 day and 80.4 mL/day respectively. The methane potential of mixed sludge was higher than individual sludge. So high methane potential was expected by controlling mixing ratio of food waste. Besides stable operation of digestion tank and the solution of oligotrophic problem were possible.

• Korean Journal of Food Science and Technology
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• v.13 no.2
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• pp.91-100
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• 1981

As a primary study for SCP production from soybean curd waste water, selection of yeast and optimum cultivation condition of selected yeast on soybean curd waste water were investigated. Eighteen strains of the genus Candida and Saccharamyces were tested to compare their abilities to grow on soybean curd waste water. Candida utilis YUFE 1508 and Candida guilliermondii KFCC 35120 grew most successfully. Optimum pH and optimum temperature of the basal medium for growth of the two strains were $6.0{\sim}6.5$ and $25^{\circ}C$, respectively. The optimum culture medium of the two yeasts was soybean curd waste water supplemented with molasses 2.5% (as total sugar), ammonium acetate 0.1-0.3% (as nitrogen), $KH_2PO_4$ 0.1-0.2% (as phosphorus), and $K_2HPO_4$ 0.05% (as phosphorus). But yeast growth was not affected by metal salts. Under the optimum cultivation condition, the maximum cell weights of Candida utilis YUFE 1508 and Candida guillfermondii KFCC 35120 were 1.313g and 1.322g/100ml of culture broth respectively after 48 hr of cultivation. The cell yields of Candida utilis YUFE 1508 and Candida guilliermondii KFCC 35120 were 68.4% and 74.2%, respectively, based on utilized sugar. On the other hand, crude protein of dry yeast produced by Candida utilis YUFE 1508 and Candida guilliermondii KFCC 35120 under optimum condition was 54.0% and 56.8%, respectively.

• Journal of the Korean Ceramic Society
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• v.48 no.1
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• pp.46-51
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• 2011

The influx of Western culture and the food culture have altered the tableware of Korea, increasing the amount of using tableware. The representative tableware is known as bone china. Considering not only the amount of bone china waste generated from broken tableware at homes and but also faulty bone china products at factories, the bone china waste disposed in simple landfills is to be a serious environmental problem to solve. In this study, following "the research on development of ceramics body using waste celadon" of which the possibility was confirmed, development of ceramics body is conducted by recycling waste bone china. From the result of the study, it was understood that maximum addition of waste bone china was 20% of the whole material on the basis of measurement of plasticity. So 20% of pulverized bone china was added and the characteristics were evaluated, and the result was that porosity, water absorptivity and plasticity were 0.756%, 0.339% and 24.13%, respectively. Bending strength was $672\;kgf/cm^2$, which showed a good sintering condition. Therefore, it was considered that waste bone china could be utilized for development of new porcelain material.

• Korean Institute of Interior Design Journal
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• v.20 no.5
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• pp.178-187
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• 2011

This research suggested the hygienic spatial composition of sell-service restaurants applying HACCP(Hazard Analysis and Critical Control Point System). The circulation of the food, dishes, waste, workers and customers were each fractionated and arranged according to the hygienic sequence of cooking food in kitchen and process for eating food within the customer space. The spaces were separated by the degree of cleanness(clean area, semi-clean area, contaminated area). After that, hygiene facilities to remove contamination and pass facilities intended to control moving were added at the possible points of cross-contamination in oder to prevent the cross-contamination. For hygienic spatial composition of self-service restaurant, the following should be acknowledged: In the kitchen, spaces in which the food is handled after being heated should be located in the clean area. As of the customer space, spaces where dishes are prepared, food and water is received, and the table hall should be located in the clean area. Food circulation should flow from the contaminated area to the clean area. Food, dishes, waste should be moved through pass facilities so that workers do not have to come and go between other areas of cleanness. Also lockers for private clothes and lockers for uniforms should be separated. Hygiene facilities should be easily accessible so that workers can use them whenever they enter their working area. The contaminated area where dirty dishes are dealed with should be separated from the clean area. Waste should be thrown out without crossing cooking areas. As of customer circulation, the hygiene facility for hand washing should be located near the space where dishes for self-service are placed. The customer circulation should lead customers to leave restaurants after giving back the dirty dishes in the contaminated area.

• Journal of environmental and Sanitary engineering
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• v.22 no.4
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• pp.105-117
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• 2007

The research was conducted based on the 1012 cases questionnaire for the purpose of to evaluate the change effect of university student's consciousness and behavior before and after lecture on environmental problems. And this questionnaires were performed with self-administered by the university student who made a application for liberal arts related to environmental subjects. The results were as follows. According to the analysis results the most students responded that the most serious problem of environmental pollution before the lecture on environmental education was a genetic modified organism(3.64/4.00), but the most serious problem of environmental pollution was changed to the topic of water pollution(3.96/4.00) after the lecture on environmental problem. And also according to the analysis results dributed by gender were that boy students show a higher concerning(170%) than that of girl students(150%). The most good results obtained after lecture on environmental problem were water pollution(23.0%), air pollution(11.5%), waste material pollution(10.9%), food additives (10.0%), genetic modified organism(8.0%), endocrine disrupter(7.5%), respectively. And according to the analysis results distributed by a grade were that the concerning of a low grade(freshman, sophomore)were higher than that of a high grade(junior, senior) in the topic of water pollution, air pollution, waste material pollution. But there were high level of awareness on the topic of food additives, genetic modified organism, endocrine disrupter to the all students(freshman to senior). And according to the analysis results distributed by a major field of study were that students who major in art & athletics, liberal art and etc(public health) were show a deep concerning than that of science & engineering. Finally, the environmental education during the university class were effectively contribute to increase the awareness of the seriousness of environmental pollution problem(8.2%) and also contribute to the practical life after class also increase their consciousness of environmental problem(59.8%).