• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.1
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• pp.15-23
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• 1997

Commercial inocula and mature compost were added separately to food wastes in order to compare the inoculating effect on garbage decomposition. Among commercial inocula available in the market, GM (Green Microorganisms) and EM (Effective Microorganisms) were selected as test inocula. Garbage decompostion were evaluated in Volatile Solid (VS) reduction and FDA (Fluorescein DiAcetate) hydrolysis activity. VS reduction with mature compost experiment was higher than that with GM-added one. VS reduction rates were about 32% with mature compost and 27% with GM. When food wastes were treated with GM and EM based on the manufacturer's specifications, GM-added and EM-added food wastes showed only 8% and 9% of VS reduction respectively, which are much lower than those with the mature compost. FDA hydrolysis activity increased during the first 10 days of active composting periods for the composting experiments, while it decreased continuously for the experiments based on manufacturer's specifications.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.1
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• pp.23-31
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• 1996

The heavy metal concentration in mixed and separately collected household food waste, and their compost during the composting period was analysed. The mixed and separately collected food waste had Cd content of 8 mg/kg in spring and its content of 13 mg/kg in winter respectively. Its content was higher than by-product compost limit value(5 mg Cd/kg). Cd concentration in separately collected food waste in a house was higher in January, February, April and May than by-product compost limit value (5 mg Cd/kg). When Cd concentration in the initial composting material was higher than 5 mg/kg, its concentration in the compost of household food waste during the composting period was higher than by-product compost limit value, but it was not accumulated in the compost during the composting period. Fly ash was added to separately collected household food waste to adjust its moisture content for composting. Its addition had moisture conditioning and Cd concentration reducing effect in the compost. The average one month composted fresh compost from the mixed collected household food waste was matured in a pile out of doors for 7 months with turning the pile once a month and its heavy metal concentration was examined. Accumulation of the heavy metals in the compost did not occur during the composting period, because they were washed out during the rainfall.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.1
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• pp.75-86
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• 1994

Garbage composting was studied in a controlled batch reactor with the addition of cooked rice as a biodegradable carbon source to find the effect of C/N ratio control on composting. And composting of bulking agents such as sawdust and wheat straw were tested with the addition of ammonium sulfate as a nitrogen source. As expected, biodegradation of the garbage having low C/N ratio was improved to some extent when foreign carbon was added. But bulking agents used in this study exerted slightly biodegradable carbon potential, indicating that the estimation of the dose of additional carbon considering desirable C/N ratio was not reasonable when lignocellulosic bulking material was added to garbage. It was found that the optimum moisture content increased with sawdust addition meaning the C/N ratio increment. Considering the above results, it was suggested that 78g sawdust per 100g garbage should be mixed to make C/N ratio to 25 and moisture content to 56% for effective composting of the garbage studied in this paper.

• 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.

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.2
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• pp.7-16
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• 1997

The food waste composting facility of 10 ton/d capacity at Nanjido has been operated successfully since July, 1996. This study was performed to investigate the characteristics of food waste quality, and variation of physicochemical characteristics of feed materials during composting. Food waste with 79% moisture content was used as a substrate. Wood chip was used as a bulking agent. Monitoring results based on VS, TOC, C/N ratio and gas composition indicated that the facility was operated normally under aerobic conditions. Conductivity values during food waste composting were increased. A highly positive correlation (r=1.00) existed between VS and TOC.

• Journal of Animal Environmental Science
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• v.15 no.1
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• pp.59-68
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• 2009

This study investigated the evaluation of maturity, stability, nutrient and heavy metal from rotating drum composter of food waste amended with poultry manure composting inoculated with effective microorganisms(EM). Composting were performed for the first, drying reactor($15m^3$) 3 hours and the second, composting reactor($30m^3$) 24 hours, and parameters monitored this period included moisture content, NaCl, pH, electrical conductivity(EC), C/N ratio, organic matter(OM), nutrient content and heavy metal. Changes in compost temperature during composting were maintained constantly in the range of $60{\sim}80^{\circ}C$ using firewood boiler(450 MJ/h). We examined physicochemical parameters and heavy metals in order to assess their effectiveness as stability and maturity, nutrient and harmful indicators such as seed germination rate<60%, potassium 1>%, dm and NaCl>1%, dm at the end of the final compost. The finished compost obtained after decomposition phase at the end of the 2nd composter could not be utilized for land improvement or reclamation.

• 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 the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.73-80
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• 2000

The objective of study was to evaluate the apropriate maturity indices for garbage composting using sawdust as bulking agent. Materials used in this study were the average composition garbage(G20) and garbage conditioned by sawdust(GS30, GS50) and cereals(GSC30). Indices for evaluating maturity were VS, water soluble TOC, polysaccharide, Humification Index(HI), and E4/E6. Experiment results showed that VS reduction was the most desirable index for evaluating compost maturity except for the GS50 which were conditioned with high sawdust Water soluble TOC decreased rapidly during the composting of first one month and then little changed. Therefore, water soluble TOC was recommended as maturity index. Polysaccharide was considered as a maturity index in case of garbage conditioned with sawdust and high cereals. Humification Index(HI) and E4/E6 were available as maturity indices in case of only some garbage composting so additional study was needed to confirm them as maturity indices for all garbage composting. Correlation analysis indicated that indices for evaluating maturity of garbage(about 30 C/N ratio) adding sawdust as bulking agent and high cereals, were VS reduction, water soluble TOC, polysaccharide, and E4/E6.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.2
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• pp.117-124
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• 2003

The purpose of this study was to investigate the optical conditions to satisfied the salt concentration of 1% below of compost produced by using the material of foodwaste and sawdust. We changed the mixing ratios of foodwaste : sawdust from 7:3 to 3:7 and the ratios of foodwaste : rice hull from 6.5:3.5 to 4:6. We analyzed C/N, pH, temperature, water content, volatile solid, salt, heavy metals to check the degree of composting. The running conditions of composting were $80{\sim}133{\ell}/min{\cdot}m^{3}$ of air flow rate, 1:4 of time interval(on:off) and 7days of turning interval. Running times were 28days. The optical mixing ratio of foodwaste : sawdust was 6:4 when we compared many factors. Especially when the mixing ratios of foodwaste : sawdust or foodwaste : sawdust were 7:3 or 6:4, the composting was not accomplished by the reason of low C/N. The concentrations of heavy metal were sufficiently low to satisfied the satandard of organic compost. The salt concentration was 0.43%-0.46% that was the half of initial concentration. The rice hull was the good in pore rate and 통기성, and so it can used alternative material.

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.1
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• pp.53-61
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• 1997

This study was conducted to analysis citizen's attitude and style to the foodwaste from l0th Sept. to 30th Sept. in 1996. The research was used questionare method and analysis was used prequency analysis and cross table method by SPSS (scientific statistics). The foodwaste of householdwaste account for 24.8%, and the magnitude by the kinds of garbage were waste from pre-cocking stage, fruitshell, foodwaste remained after eating, septic foodwaste during storage. The more the housewives'age are young, foodwaste volumne were much. Most remained foodwaste after eating were soup and pot stew. The main cause of foodwaste production was overvolumne cooking. 88.8% of answers think that a menu can be useful to reduce foodwaste. The survey showed that 87.3% of answers put into the meter-rate bag after removed wetness of garbage. 84.1% of answers thought that the recycling of foodwaste needed, but the practical housewife was only 21%. For the suitable treatment of foodwaste, Survey showed that the consistent policy of goverment and continuous publicity was needed essentially, and that the public notice of TV or radio was effective. All of answers would like to participate in recycling of foodwastes whether public-posting or personal-posting. To set up vessel of posting at household, the proper purchase price and space of institution are needed, also the solution of sanitory & aesthetic problem and the collection of composting-product must be achieved smoothly.