• Journal of the Korean Dietetic Association
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• v.7 no.4
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• pp.410-425
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• 2001

This study was designed to assess the waste management practices, source-reduction programs and related tasks in elementary school foodservice in Seoul. and Kyonggi Province Areas. A questionnaire mailed to 910 school foodservice managers in Seoul and Kyonggi province: a 202% (N=184) response rate was obtained. About 83.7% of school foodservice managers were responsible for managing solid waste. Most foodservice operations take the responsibility of food waste but not packaging wastes. The average disposal cost per month per person was about 19 won and income was about 35 won. Leftovers were mainly disposed with platewaste. Platewaste was reused for the livestook feed(68.0%), and some platewaste was composted(11.6%). Source reduction programs implemented in half of school foodservice operations were adjustment of portion size', checking the plate waste', 'working with classroom teachers on waste reduction campaign', 'providing information leaflet on food waste minimization', posting education materials, 'classroom instruction about food waste minimization', and 'improving cooking method. According to factor analysis based on importance rating. slid waste management activities of elementary school foodservice operations were divided to 7 dimensions such as communication and cooperation with others', 'employee training', 'product quality control, 'yield control', plate waste control', 'purchasing', and 'public relations'. As a result of Important-Performance Analysis(IPA), sine dimensions such as 'communication and cooperation with others' and 'plate waste control were identified in Focus Here' quardrant area which need more enhanced performance.

• Solar Energy
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• v.18 no.3
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• pp.197-203
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• 1998

A 5 ton/day pilot scale two-phase anaerobic digester was constructed and tasted to treat Korean food wastes in Anyang city. The process was developed based on 3 years of lab-scale experimental results on am optimim treatment method for the recovery of biogas and humus. Problems related to food waste are ever Increasing quantity among municipal solid wastes(MSW) and high moisture and salt contents. Thus our food waste produces large amounts of leachate and bed odor in landfill sites which are being exhausted. The easily degradable presorted food waste was efficiently treated in the two-phase anaerobic digestion process. The waste contained in plastic bags was shredded and then screened for the removal of inert material such as fabrics and plastics, and subsequently put into the two-stage reactors. Heavy and light inerts such as bones, shells, spoons and plastic pieces were again removed by gravity differences. The residual organic component was effectively hydrolyzed and acidified in the first reactor with 5 days space time at pH of about 6.5. The second, methanization reactor part of which is filled with anaerobic fillters, converted the acids into methane with pH between 7.4 to 7.8. The space time for the second reactor was 15 days. The effluent from the second reactor was recycled to the first reactor to provide alkalinities. The process showed stable steady state operation with the maximum organic rate of 7.9 $kgVS/m^3day$ and the volatile solid reduction efficiency of about 70%. The total of 3.6 tons presorted MSW containing 2.9 tons of food organic was treated to produce about $230m^3$ of biogas with 70% of methane and 80kg humus. This process is extended to full scale treating 15 tons of food waste a day in Euiwang city and the produced biogas is utilized for the heating/cooling of adjacent buildings.

• Journal of Korean Society on Water Environment
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• v.30 no.5
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• pp.559-567
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• 2014

Since the ocean dumping of organic wastes is prohibited under the London Convention, the need for land treatment of food waste leachate (FWL) has significantly been growing in recent years. This study was conducted to use thermal solubilization to turn FWL into a form that can easily be degraded during the anaerobic digestion process, thereby reducing the percentage of solids and increasing the production of methane. To derive the optimal operating conditions of thermal solubilization, a laboratory-scale reactor was built and operated. The optimal reaction temperature and time turned out to be $190^{\circ}C$ and 90 min, respectively. The BMP test showed a methane production of 465 mL $CH_4/g$ $COD_{Cr}$ and a biodegradation rate of 90.1%. The production of methane rose by about 15%, compared with no the application of thermal solubilization. To reduce the solid content of FWL and improve the methane production, therefore, it may be helpful to apply thermal solubilization to pre-treatment facilities for anaerobic digestion.

• Journal of Environmental Health Sciences
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• v.24 no.1
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• pp.120-131
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• 1998

This study was performed to define the physicochemical characteristics of food waste and food wastewater, and to find the effect of moisture content variation and salinity variation on aerobic composting for food wastes. In moisture content variation experiment, the samples of 2-1, 2-2, 2-3 and 24 were prepared by the moisture content of 83.8%, 70.9%, 64.8% and 45.1%, respectively. In salinity variation experiment, the samples of 3-1, 3-2, 3-3 and 3-4 were prepared by the salinity of 0.99%, 1. 69%, 1.75% and 2.34%, respectively. In both experiments, aerobic composting reactors were operated by the mode which was composed of half an hour's stirring and 2 hour's aeration per day, for 45 days. The followings are the conclusions that were derived from this study. 1. In the study of physicochemical characteristics of food waste and food wastewater, the values of pH were 4.19 and 3.96, the values of salinity were 0.91% and 1.17%, and the values of conductivity were 7.6 mS/cm and 18.2 mS/cm, respectively. 2. In food waste, the moisture content was 60.3%, organic compound content was 96.1%, total carbon was 48.0%, total nitrogen was 1.5%(therefore, C/N ratio was 32), and the concentration of total phosphorus was 1.34 mg/kg. 3. The time of temperature ascending was delayed, the highest temperature was lowered, the duration period of high temperature was shortened by the increasing of moisture content. In the higher moisture content, anaerobic condition was formed, bad smell was released, insects were gathered and multiplicated, and the reaction rate of composting was reduced. 4. In moisture content experiment, C/N ratios were changed from the range of 31.2-34.8 at the beginning phase to that of 20.4-28.4 at the last phase. 5. In salinity experiment, the reduction rate of volume was increased(40.3%) when the salinity was decreased(0.99%). Also, the reduction rate of mass was increased(51.8%) when the salinity was decreased(0.99%). This fact denotes that salinity hinders the process of composting. 6. the concentrations of total nitrogen and total phosphorus were increased from 0.74% to 1.10%, and from 0.82 mg/kg to 3.44 mg/kg, respectively when the salinity was decreased from 2.34% to 0.99%.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.4
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• pp.513-520
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• 2012

The use of food waste disposers (FWDs) can be an emerging option to manage organic food wastes in municipal sewage system. The cost-benefit analysis (CBA) of introducing domestic FDWs is conducted to access the allowable disposer market price and the economic impact on food waste management from conventional solid waste management system. If the convenience value of 10,000 won/month is taken into consideration based on survey results, the introduction of FDWs can lead to net economic benefits, allowing the capital cost of disposer up to 1,000,000 won/unit. Without the consideration of convenience value, the introduction of FWDs becomes profitable if the capital cost of disposer is less than 50,000 won/unit. In case that the value of convenience is more than 7,000 won/month, the reduction of food waste management cost is not valid for the introduction of FWDs to be non-profitable. However, if environmental externalities are considered, the proposed system could become breakeven with the cost of food waste management decreases by 54 % (60,000 won per ton).

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.3
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• pp.47-54
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• 2018

This study examined the improvement of anaerobic digestion rate and sludge reduction as a result of the addition of anaerobic digestion with thickened sludge and solution of VFAs obtained from food waste. The methane production rate of the digestion system was 2.21 times higher when anaerobic digestion reactor injected into anaerobes with VFAs from food wastes of 5 percent. Also, The reduction of the amount of concentrated sludge injected will proceed rapidly because of the TCOD concentration in the digestion reactor was more than twice higher. Indirectly it was shown that the increased production system contributed significantly to the methane production efficiency.

• Journal of Power System Engineering
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• v.12 no.1
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• pp.35-40
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• 2008

This paper presents an effective cooling dehumidification method to remove odorous gas from food-wastes. The odorous gases, such as Styrene, Ammonia, Hydrogen sulfide and Acetaldehyde, are produced in environments where temperature is $50\sim80^{\circ}C$ and humidity is $40\sim70%$. Under such conditions, experiments are performed reiteratively using experiment equipments. The effect of the cooling dehumidification is measured via measuring instrument, and this research is focused on improving efficiency. The effect of cooling dehumidification using measuring instrument is validated. At $80^{\circ}C$, four type of gases that was mentioned previously showed generally better cooling efficiency with a good result for a component concentration. Among them, hydrogen sulfide gas demonstrated the highest reduction of 50%.

• Journal of Electrochemical Science and Technology
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• v.8 no.1
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• pp.77-86
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• 2017

The valorization of domestic wastes becomes a very important research axis that can reduce the energy consumption and protect our environment. The objective of this study is to remove zinc ions from wastewater by using banana peels after their activation as sensor in the working electrode for an environmental application. Banana peels were dried, crushed and treated with sulfuric acid then mixed with polyaniline to improve their electrical conductivity. Cyclic voltammetry and chronoamperometry were used for electrochemistry tests. The obtained voltammogramms at well optimized conditions of applied potential of -1.3 V/SCE and initial zinc concentration of 0.2M during 2 hours of electrolysis, showed the reduction peak of the zinc at a potential of -1.14 V/SCE, which confirmed the activity of this electrode. The modeling of experimental data revealed that the adsorption was fitted by the Langmuir isotherm with a maximal adsorption capacity of 3.4188 mg/g. Changes in the structure of the powder after the electrosorption was noticed by SEM and EDX. Finally, the dosage of the electrolytic solution showed a diminution of the zinc concentration with yield of 99.99%.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.1
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• pp.64-73
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• 1999

The purpose of this study was to estimate the effect of serving sizes on dish wastes, nutrient intake, and diet satisfaction for reduction of dish waste products. The dish waste, energy and protein intake, and satisfaction scores before and after dining were compared in 44 subjects fed various serving sizes(100%, 90%, 80% of standard size) of 10 frequently consumed Korean dishes. The result are as follows: 1. Average age, height, and weight of 44 subjects were 30.5, 174.0cm, and 68.1kg in men and 26.2, 164.2cm, and 53.5kg in women, respectively. 2. There was a significant difference in the dish waste rate of 10 Korean dishes to serving sizes. The range of dish waste rates of 10 Korean dishes was 13.14-33.04%. 3. The average energy intake from 10 Korean dishes in which 100% of the standard serving size was served was lower than Korean RDA. Protein intakes from Sulungtang, Yukgaejang, Deunjang-ggigae, and Bibimpab with 100% servins size, Soondubi-ggigae 90% servins size, and Galbitang, Bulgogi-bakpan, Sangsungui-bakpan, Bakpan 80% of standard serving size were higher than Korean RDA. 4. The satisfaction score before dining on Sulungtang, Bulgogi-bakpan, Sangsungui-bakpan decreased with decreasing serving size. However, there was no significant difference in satisfaction score after dining to serving size. These findings indicate that dish waste rate and diet satisfaction of 10 these Korean dishes are fixed and energy intake is insufficient. Therefore, for reduction of food waste and reasonable serving size of dishes evaluated in this study, there should be more studies about Korean menu development with decreasing serving size and increasing energy density.

• Journal of Environmental Health Sciences
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• v.27 no.3
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• pp.21-26
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• 2001

This study was performed to define the physicochemical characteristics of food waste and food wastewater, and to find the effect of salinity variation experiment, the samples of 1, 2, 3 and 4 were prepared by the salinity of 1.0%, 1.5%, 2.0% and 2.5%, respectively. In experiment, aerobic composting reactors were operated by the model which was composed of half an hour's stirring and 2 hour's aeration per day, for 45 days. Seeds of vegetables of Chinese cabbage and red pepper were seeded at compost-free control, compost 1, 2, 3 and compost 4 for the sake of investigation of germination rate and growth rate of those. The followings are the conclusions that were derived from this study. 1. In food waste, the moisture content was 60%, organic compound content was 95%, total carbon was 47.5%, total nitrogen was 1.6%(therefore, C/N ratio was 30). The values of pH were 4.0 and 3.8 the values of salinity were 0.9% and 1.2%, and the values of conductivity were 7.8 mS/cm and 18.0 mS/cm, respectively. 2. In salinity experiment, the reduction rate of volume was increased(40%) when the salinity was decreased(1.0%). Also, the reduction rate of mass was increased(52%) when the salinity was decreased(1.0%). This fact denotes that salinity hinders the process of composting. 3. Germination rate and growth rate of Chinese cabbage are more excellent than those of red pepper(97.14%, 5.2:2.5 cm). 4. In Chinese cabbage, germination rate and growth rate at compost with the lowest salinity are more excellent than those at compost-free control(97:94%, 5.2:4.5 cm).