• 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.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.3
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• pp.51-62
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• 2005

The effects of the processing mixture of food wastes and various organic wastes when vermicomposted on earthworm(Eisenia foefida) growth, the cast production amounts and the chemical properties of casts were evaluated. The substrates used in this experiments were cow manure, pig manure sludge, fermented pig manure with sawdust, nightsoil sludge, and sewage sludge and were respectively mixed with food wastes at a ratios of 50:50(v/v). The control consisted of food wastes alone without other wastes. All of earthworm died in the food wastes 100%, therefore the process of food wastes alone by vermicomposting was impossible in this experiment. Worm cast produced sufficiently contained quantities of available phosphorus, exchangeable potassium, exchangeable magnesium, and cation exchange capacity. The increase of earthworm's biomass occured on the mixtures of food wastes and cow manure, fermented pig manure with sawdust. Dry weight of worm cast was the highest on the mixtures of food wastes and fermented pig manure with sawdust and the proportion of cast weight after vermicomposting was significantly the highest on the mixtures of food wastes and cow manure($p{\leq}0.05$). Also, the mixtures of food wastes and cow manure, and fermented pig manure with sawdust showed a positive values of conversion rate and conversion efficiency rate of organic matter to earthworm tissue than that of other treatments. These results suggested that cow manure and fermented pig manure with sawdust are adequate to process with food wastes by vermicomposting.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.4
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• pp.55-60
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• 2001

This study was performed to investigate production characterisitic of methane gas in anaerobic digestion reactor according to input type of food waste. In the production rates of $CH_4$ gas per g $VS_{added}$, reactor R2, R3, R4, R5, and R6 in which sewage sludge and food waste were combined with mixing ratio of 1:0.1, 1:0.3, 1:0.5, 1:1, and 1:2 showed 85mL, 62mL, 67mL, 72mL, and 73mL $CH_4/g$ $VS_{added}$ which were much more than sewage sludge digestion alone. Methane content according to crushing size of food waste respectively showed 51.1%(raw food), 53.1%(2~4mm), and 50.6%(<2mm), In case of methane production according to washing of food waste, R12(7~8 times washing) showed the highest methane production.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.96-101
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• 2002

This research was conducted to find the optimal condition in codigestion of food waste and sewage sludge with various mixing ratios. The analysis of degradation characteristics were based on the variations of methane production as well as methane production rate (MPR). BMP values were getting higher as the addition of foodwaste increased. But the lag-phase were prolonged when the foodwaste was over 40%, Nonlinear regression was conducted with the cumulative methane production data. Not only thermophilic but mesophilic condition, 40% of foodwaste addition showed maximum MPR. Higher mixing ratio which is over 50% were unprofitable in gaining higher MPR values. The most important factor in thermophilic co-digestion was substrate concentration. But in mesophilic co-digestion, both substrate concentration the mixing ratio had major effects on MPR. The most probable reasons of the synergetic effects in co-digestion of foodwaste and sewage sludge were the balanced nutrient expressed as C/N ratio and increased kinetic constants of hydrolysis by the mixed co-substrates.

• KSBB Journal
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• v.22 no.2
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• pp.97-101
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• 2007

This study was performed to examine the availability of anaerobic digestion of the remainders caused by bacterial cellulose production process using food wastes. They maybe to be considered as others second pollution sources. Thus, this study was targeted to minimize content of organic material and to obtain more energy in those remnants using two-phase UASB reactor. The working volume of first hydrolysis fermentor was 35 L (total 55 L) and the second methane fermentor was 40 L (total 50 L). The organic loading rate of hydrolysis fermentor was 3 g-VS/L${\cdot}$day and 25,000 ppm of $COD_{cr}$ for methane fermentor. The hydraulic retention time was 18 days for hydrolysis reactor and 33 days for methane reactor. The hydrolysis reactor and methane reactor were performed at 35, 40$^{\circ}C$ respectively. For the efficient stable performance, the composition of organic wastes at each stage was as follow; Food waste with bacterial culture remnants (1 : 1), bacterial cellulose remnants, bacterial cellulose culture remnants with food wastes saccharified solids (1 : 1). When the anaerobic digestion was performed stably at each stage, the COD removal efficiency was 88, 90, 91 % respectively. At this time, methane production rate was 0.26, 0.34, $0.32m^3\;CH_4/kg-COD_{remove}$. As well as the values of anaerobic digestion at third stage were more higher than values of anaerobic digestion using food wastes. It is clearly to say that the food wastes zero-emission system constructed in our lab is more efficient way to treat and reclaim food wastes.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.4
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• pp.43-49
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• 2008

Objective of this study was to monitor the hydrogen sulfide production rate and concentration in anaerobic co-digestion of swine manure and food waste for biogas production in order to alternate the petroleum based energy. Anaerobic co-digestion for biogas production was performed in serum bottles at 2% volatile solids (VS) concentration and various mixing ratios of two substrates(swine manure: food waste = 100:0 ~ 0:100). Although hydrogen sulfide production rates were varied with digestion periods at different treatments, it was observed that hydrogen sulfide produced in the swine manure alone was lower at 2.4 fold than that of food waste. For effects of hydrogen sulfide concentration in the different mixing ratios of swine manure to food waste, the higher food waste ratio the higher hydrogen sulfide concentration. Also its average concentrations were varied from 0.1452% in the swine waste only to 0.3420% in the food waste alone. For the composition ratio of bio-gas in their anaerobic co-digestion, it appeared that there was 53.2% of $CH_4$, 23.9% of $CO_2$, 0.3% of $H_2S$ and 22.7% of miscellaneous gases including moisture.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.83-90
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• 2006

The NaCl contents of food waste composts made by various techniques known up to now were under the level of 1% by fresh weight basis. But these techniques has some problem that is environment pollution from treated water and high equipment cost. The application to agricultural land of food waste compost that is not sufficiently removed NaCl was considered to be improper due to salt accumulation in soils and plant growth inhibition by salt stress. The purpose of this study is to decompose NaCl in food waste compost using triple salt and this method is differ from existing chemical method. Also, reaction of NaCl with triple salt produced KCl that is basic material of potassium fertilizer. Moreover Also, there was temperature rise of average $5^{\circ}C$ as result that apply triple salt in food waste 600 ton in food wast composting productive capacity. Obvious odious smell reduction effect appeared pretreatment process and fermentation process with temperature rise and this is because triple salt activation of aerobe and removes odious smell cause material by salt content decrease effectively.

• 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.10 no.2
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• pp.65-70
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• 2002

The previous studies showed that rumen microorganisms had an enhanced waste-degrading capability and controlling the dilution rate was very effective in improving acidification efficiency. Generally the composition of food waste has a small deviation value, but one of the waste components (grains, vegetables or meats) can be increased dramatically depending on a seasonal variation. Thus, it is important to evaluate the efficiency of acidogenic fermentation in this case. Each component was spiked to be 80% of the total waste in R1 (grains), R2(vegetables), and R3 (meats). In Rl, rapid degradation occurred during the initial two days. R2 showed similar performance to that of general food waste. In R3, degradation retarded in the initial stage and then increased after controlling the dilution rate. The acidification efficiencies of the reactors were 88.7 (R1), 73.5 (R2), and 62.1% (R3), respectively. Therefore, the fermentation efficiency was kept over 62% regardless of waste components, indicating that it was stable to acidify food waste by employing rumen microorganisms and controlling the dilution rate.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.2
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• pp.33-40
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• 2011

This study was conducted for the purpose of examining stable disposal of foodwaste and possibility of multilateral use of its by-product by mixing earthworm powder and by-product generated from food waste disposal for making feed for sea fish. As a result of the study, content of crude protein (25.93%, 69.72%), crude lipid (16.91%,6.39%) crude ash (15.38%, 5.30%) in by-product of food waste and earthworm powder was higher than that in fish meals manufactured in the country, and it was judged that it is available to make good feed as a source of fatty acid as it contained C18:1n9c, 1n9t and c16:0. As for stability as a raw material for feed, it was shown that the stability was high when using the product as a raw material for feed not exceeding the standard of test items, and though change of content and ingredients to mixing ratio, it was shown that mixed specimen of fertilizer (S6) was higher, showing that it has great utilization in the future. Also, as it has more content of registered ingredients than any other raw materials for feed manufactured in the country, it is possible to be used as a substitute when manufacturing feed for sea fish. Therefore, it is judged that various studies such as economic analysis and technology of possible manufacturing will be needed in the future.