• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.2
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• pp.29-37
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• 1997

Because food waste have high moisture content, landfill or incineration is not most suitable. The reuse of food waste by composting contribute to solve resourse, environmental, aglicultural problems. The purpose of this research is to optimise operating conditions and to develop new microorganisms for recycling of food waste by ultilizing small-scale composting equipment. The reduction rate of food waste was 75~85% by weight, and it was coincided with moisture reduction. When initial moisture was 25%, 45% and 60%, C/N ratio on based net weight was 9.8, 10.7 and 11. 8, respectively. And it was suitable for composting. But, The developed microorganism, PNU2, was better than existing commercial seed in the activity based on $CO_2$ concentration.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.1
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• pp.43-51
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• 1996

Qualititative changes in water extracts during food waste composting were studied in order to identify parameters that can be used as indicaters of compost maturity. Materials used in this study were food wastes, office paper, newspaper and leaves. Three different compositions of food wastes were used : average composition food waste generated in Korea, a high cereal (carbohydrate) content food waste and a high meat (protein) content food waste. Experimental results indicated that parameters which can be used for compost maturity evaluation were water soluble TOC and water soluble $C_{org}/N_{org}$ ratio. In case of water soluble TOC, it is considered as one of the most desirable parameters, since it showed quite distinct decrease pattern than any other parameters. The $C_{org}/N_{org}$ ratio in the water extracts can also be considered as a appropriate index of the compost maturity since this ratio reached a narrow range (5~6) at the end of composting process regardless of initial raw waste compositions. Water soluble TKN was undesirable parameter as a compost maturity index. The ammonia nitrogen content in water extracts varied considerably during composting process, but finally reached a range of 0.067, 0.085% based on dry compost.

• Journal of Environmental Health Sciences
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• v.26 no.3
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• pp.1-10
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• 2000

Although microorganisms play an important role in composting process, researches on the effective microorganism (EM) in composting process are rarely reported. In this study, three stages of work performed 1) investigation of composting facility 2) sample collection and isolation of the EM 3) lab-scale composting by seeding the isolated EM. For this, purpose, physical, chemical, and biological characteristics, such as temperature, moisture content, organic matter, pH population of microorganism, etc., were investigated during the process and the results were compared with those of a control(non-seeded). In the composting facility, the most active degradation of food waste was suppsed to occur in 10-11th day of composting by observing the temperature and CO2 emission. The population of bacterial and fungi was highest in thermophilic stage. Meanwhile that of actinomycetes and yeast was relatively uniform during the process. In the lab-scale test, the thermophilic stage was maintained longer(more than 9 days in 17 days of experiment) in the seeded which was favored for the high reduction of organic matter and moisture. Reduction rates of lipids and salinity were also increased in the seeded. It confirmed these results that the population of microorganisms in the seeded was observed higher in several orders than the control. However, pH of the seeded was maintained as low as about 4.5 throughout the experiment except the final period of the process. Meanwhile, pH of the control rose in the early stage of the experiment. This was probably due that the seeded microorganisms collected from the composting facility was adapted to the low pH environment.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.81-88
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• 2000

Composting of N-rich wastes such as food waste and wastewater sludges can be associated loss of with substantial gaseous N, which means loss of an essential plant nutrient but may also lead to environmental pollution. We investigated the behavior of nitrogenous materials during the first high-rate phase in composting of food waste. Air dried food waste was mixed with shredded waste paper or wood chip and reacted in a bench scale composting reactor. Samples were analyzed for pH, ammonia, oxidized nitrogen and organic nitrogen. The volatilized ammonia nitrogen was also analyzed using sulfuric acid as an absorbent solution. Initial progress of composting reaction greatly influenced the ammonification of organic nitrogen. A well-balanced composting reaction with an addition of active compost as an inoculum resulted in the promoted mineralization of organic nitrogen and volatilization of ammonia. The prolongation of initial low pH period delayed the production of ammonia. It was also found that nitrogen loss was highly dependent on the air flow supplied. With an increase in input air flow, the loss of nitrogen as an ammonia also increased, resulted in substantial reduction of ammonia content in compost. The conversion ratio of initial nitrogen into ammonia was in the range of 28 to 38% and about 77~94% of the ammonia produced was escaped as a gas. Material balance on the nitrogenous materials was demonstrated to provide an information of importance on the behavior of nitrogen in composting reaction.

• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.96-104
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• 1999

A questionary survey was conducted to investigate citizen's attitude to the treatment of food wastes in Miryang city. In this study, collection effectives was 87.8%, as 281 individuals among 320 individuals. After volume-base charge system, 86.8% of answers perform source separation and 60.9% of respondents separate everything of recycle goods. The majority of respondents discharge food waste using standard envelope. The biggest problems for deposition of the food wastes are offensive odor and worm for reasons of sanitation. Almost citizens think that the period of deposition suit from two days to three days. More than 90.0% of the citizens recognized that compost products made from food wastes and recognition of the people for the composting and composting facilities was affirmative. Majority of the respondents thought that the administration and the provincial government need activity publicity for the source separation fixations of the food wastes.

• Journal of Community Nutrition
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• v.4 no.2
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• pp.130-135
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• 2002

The purposes of this study were to quantify and compare the kind and amount of solid waste generated in two school foodservice operations located in urban and rural areas. A waste stream analysis was conducted to quantify and characterize the kind of waste in the production and service parts of each operation. The SPSS 10.0 for window was used for data analysis. Non-parametric test (Mann-Whitney) was adopted to determine if significant differences exist in amounts of waste generated in the urban school and the rural school. An average of 415 meals, including 43 adult meals, were served daily in the urban school, while an average of 177 meals, including 24 adult meals, were served daily in the rural school. Food waste generated in the production part in the urban school composed approximately 87% and 45%, while that in the rural school composed 71% and 28% by weight and volume, respectively. Waste per meal was not significantly different between the urban school and the rural school in the production part except the cardboard waste. The total waste per meal at lunch was 154g or 465m1 in the urban school and 51g or 334m1 in the rural school. Students in the urban school discarded significantly more food waste and milk than students in the rural school did. The research results suggest that school foodservice dietitians should evaluate the acceptability of menu items based on food waste per meal, and assess the feasibility of implementing a plan for recycling packaging waste and composting organic waste.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.760-767
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• 2016

Food waste (FW) has been recognized as a critical problem in Korea and many research was conducted to efficiently utilize or treat FW. Main purpose of this research was to evaluate a feasibility for producing fermented organic fertilizer with vegetable waste (VW). Three different organic materials (saw dust, coco peat, and waste mushroom media) were mixed with VW at the rate of 30, 40, 50% respectively. Total days of composting experiment were 35 days and each sub samples were collected at every 5 days from starting of composting. Result showed that inner temperature of composting was increased to $60{\pm}4^{\circ}C$ within 5~10 days depending on varied organic materials and mixing ratio. Among different treatment, the highest increase of inner temperature was observed when 30% of saw dust was mixed with VW. After finishing composting experiment, maturity of each compost was evaluated with solvita and germination test. Maturity index (MI) of each treatment was ranged between 5~7 indicating that manufactured fertilizer was curing or finished stage. Calculated germination index (GI) was at the range of 57.83~101.16 depending on organic materials and mixing ratio. Both MI and GI showed that manufactured fertilizer was met for fertilizer criteria while control (VW only) was not adequate for composting. Overall, VW can be utilized for making organic fertilizer mixing with saw dust, coco peat and more research should be conducted to make high quality of organic fertilizer with vegetable waste.

• Journal of the Korea Organic Resources Recycling Association
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• v.3 no.1
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• pp.3-11
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• 1995

This study was conducted to estimate the stabilization degree of compost which made from Korean food wastes. To make the compost, food wastes were mixed with dried paper sludge, sawdust and the rotten wood waste which had cultivated mushrooms, and then mixture was composted in $1.1m^3$ of chamber which installed with the blower for maintaining the aerobic condition. Y value, EC and pH were changed remarkably for the early stage of composting. These changes showed that the compost of food wastes could be stabilized within 30~35 days and that the substrate, food wastes, can be easily used as energy source for microorganisms. Although these phyico-chemical properties indicated that food wastes could be composted within 30 days during the composting, the temperature of pile maintained over $50^{\circ}C$ for 80 days, and C/N ratio decreased gradually for over 50 days. In conclusion, more than 50 days were required to stabilize the compost of food wastes.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.413-420
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• 2003

To explore the effective treatment methods for waste food generating malodor compounds, mixed microorganisms (MM) capable of deodorizing of domestic animal waste were applied using household composting box. The mixture of 5 kg whole chips as a bulk agent, 2 kg MM and 1 kg of waste food were input into the compost reactor and agitated. Waste food was supplemented every 24 hours. As the results, the composting volume was stable at 13∼14 L for 10 days. In the initial compost process with MM, the pH and temperature were increased more quickly than that of without MM. Also, the conductivity recognized as a barometer of compost was increased from 0.2 to 2.4 mS/cm that was higher than 1.3 mS/cm of without MM, for 10 days. The malodor compounds generated from waste food treatment such as sulfur compounds and volatile fatty acids were effectively reduced about 90∼l00%, and 70∼80% for 8 days, respectively. The microorganisms growing under the condition of alkaline phase and higher temperature were dominated during the compost Moreover, it was demonstrated that inoculated Bacillus cereus HY15 dominated during the compost results in responsible to the effective treatment of waste food.

• Environmental Engineering Research
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• v.23 no.1
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• pp.46-53
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• 2018

This study explores the environmentally innovative and low-impact technology, a zero food waste system (ZFWS) that utilizes food waste and converts it into composts or biofuels and curtails carbon emissions. The ZFWS not just achieves food waste reductions but recycles food waste into fertilizer. Based on a fermentation-extinction technique using bio wood chips, the ZFWS was employed in a field experiment of the system installed in a large-scale apartment complex, and the performance of the system was examined. The on-site ZFWS consisted of three primary parts: 1) a food waste slot into which food waste was injected; 2) a fermentation-extinction reactor where food waste was mixed with bio wood chips made up of complex enzyme and aseptic wood chips; and 3) deodorization equipment in which an ultraviolet and ozone photolysis method was employed. The field experiment showed that food waste injected into the ZFWS was reduced by 94%. Overall microbial activity of the food waste in the fermentation-extinction reactor was measured using adenosine tri-phosphate (ATP), and the degradation rate of organic compounds, referred to as volatile solids, increased with ATP concentration. The by-products generated from ZFWS comply with the national standard for organic fertilizer.