• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.1
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• pp.33-42
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• 1997

It is not long since treatment of food waste became a social problem. However, it is a fact that there have been a lot of debates on the treatment of food waste since several years ago. At present, two ways of disposing food waste are under great interest in Korea and Japan. One is drying of food waste at high temperature. The other is disappearance type, in which analysis by microorganism takes place with continuous supply of a bulking agent for a certain period of time that was stored in a reactor. In our laboratory, Disappearance type Food Waste Disposer is under interest, and experiments regarding condition establishment for efficient analysis of food waste were conducted. As preceding experimentation, experiments were done with regard to the selection of a substance to be used as a bulking agent, improvement by addition of a substance which maximizes initial growth of microorganism, and a concentration change in rank odors generated by reaction with deodorizer (absorbent). The results turned out to be satisfactory.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.3
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• pp.87-95
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• 2003

Although extensive studies were conduced on hydrogen fermentation of organic wastewaters, little is known about biohydrogen production from organic solid wastes. The leaching-bed reactor treating food waste by heat-shocked anaerobic sludge was, therefore, operated at D of 2.1, 3.6, 4.5 and $5.5d^{-1}$ to find optimal D for hydrogen production. Successful operation of a reactor can be accomplished when it is operated at proper dilution rate (D). Operation at high D leads to the washout of biomass in the reactor while operation at low D leads to product inhibition due to the accumulation of excess VFA. These appear to limit the production of hydrogen to reach a higher level. All the reactors showed that, on day 1-3, hydrogen production was dominant and VFA concentration was higher than ethanol. Butyrate and acetate were major components of VFAs over the whole operation, though lactate was very high on day 1-2. Compared with other D values, D of $4.5d^{-1}$, resulted in higher butyrate/acetae (B/A) ratios during the fermentation. The trend of B/A ratios was similar to the hydrogen production, suggesting that butyrate formation favored hydrogen production. Ethanol increased significantly from day 4 when hydrogen Production stopped. It indicated that heat-shocked sludge was able to induce a metabolic flow from hydrogen-and acid-producing pathway to solvent-producing pathway. Operation at D of $4.5d^{-1}$ led to higher fermentation efficiency (58%) than those (51.5, 55.3 and 53.7%) at 2.1, 3.6 and $5.5d^{-1}$. The COD removed was convened to hydrogen (10.1%), VFA (30.9%), and ethanol (17.0%).

• Journal of agricultural medicine and community health
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• v.21 no.1
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• pp.97-105
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• 1996

This study conducted to determine the evaluation and improvement for enforcement of the waste recycling system in Pohang city and surveyed 4 areas at the southern and northern districts respectively by a team of two officials during the period 6 February 7 February 1995. The rates of the use for waste recycling system's envelope from home trash were 94.2% at the northern district and 92.8% at the southern district by areas, 95.6% at the group houses (apartments and tenement houses) and 91.3% at the separate houses by patterns of house, the low economic class 96.4%, the middle economic class 96.3% and the upper economic class 87.5% by the economic levels, and the bell method 96.5%, the container method 95.6%, door take method 86.1% in order, respectively. The trash from houses were garbage 57.4%, paper 18.7%, plastic 10.3%, fiber 7.9%, bottle 2.7%, metal and can 1.4%, and wood and rubber 0.7% in order. The rates of the reuse trash(reuse possible paper, plastic, bottle, can and metal) were 20.2% of the total, 21.8% at the southern district and 18.5% at the northern district by areas, 25.7% at the separate houses and 14.7% at the group houses(apartments and tenement houses) by patterns of house, and the door take method 34.3%, the bell take method 17.1% and the container take method 14.7% in order, respectively. There were the double envelopes of the plastic bag from stories 46.3% and the clear plastic bag 29.5% in the waste cycling system's envelopes. There were 1.9 double envelopes in the waste cycling system's envelopes. Garbage occupied more than half of the total trash, so it is need to be compost and provender.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.112-120
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• 2004

In this study, the physico chemical characteristic of MSW and sludge in west area of Kangwondo was investigated for database, managing the waste and waste treatment facility. The sampling sites were selected as 6 different MSW generation area and 2 sludge generation area. it is necessary to measure the characteristics of MSW to build the data-base. The year of 2000, 197.4ton/day of MSW which was generated in this area. This MSW was composed of 26.6% food wastes, 24.2% of papers, 22.8% of plastics & vinyls, 9.6% of textiles, 3.80% of wood, 2.8% of rubbers & leathers and others, respectively. Most of MSW are composed of food, paper and plastic waste and combustible waste is more than 89%. The generation of papers and vinyls are almost same for different seasons For 3-components of MSW, moisture is 40.2%, combustible component is 52.1% and ash is 7.7% and for 3-components of sludge, moisture is 83.3%, combustible component is 7.7% and ash is 9%. The chemical element has the high order of carbon(51.6%), oxygen(38.6%), hydrogen(7%) on the dry basis of wastes. And the high heating value of MSW is 4989.4 Kcal/kg sludge is 4428.04 Kcal/kg and low heating value of the MSW which is measured by calorimeter is 2032.88kcal/kg. From the leaching test of wastes, there is no heavy metals.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.1
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• pp.90-99
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• 2005

This study was conducted to survey the attitude of Chuncheon citizens on food waste generation. About 50% of the citizens were generating $5{\sim}10{\ell}$ of MSW (municipal solid wastes) a week. These answers were almost from below 35 years old. And the citizens answered that the ratio of FW (food waste) to MSW were 10-30%. They were generating FW enveloped in a standardized vinyl bag after dewatering. About 10% of the answers were generating FW with MSW without any dewatering. The reason for FW generation in large quantities was to cook and buy much more food materials than needed. They thought that malodor and harmful insect were the most severe problems from FW storage. The systematic management was the most needed in individual restaurants. They answered that an individual citizen should make an effort to reduce FW generation. However, in fact, they did not do their best to try to reduce FW generation. They agreed that an individual citizen should try to reform 'present food culture' and to think FW as resources.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.4
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• pp.79-88
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• 2005

The wastes generated in farming or fishing villages are mostly those of high moisture content or those once used for farming or fishing work, which require a complex process even for disposing of them alone, and moreover they have been recognized to cause a secondary side effects. The study thus is intended to conduct the basic character analysis and incineration test so as to develop the thermal decomposition furnace which will be optimal in disposing of the wastes generated from urban area that mostly have a high thermal energy or require a complex treatment process. And the subject included in the study, in addition, is to design and develop the furnace aimed at reducing the harmful ingredient as well as recycling the heat generated in the course of incineration.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.79-89
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• 2003

The purpose of this study is to investigate appropriate environmental factors when domestic waste is decomposed as aerobic digestion. So stabilization degree was measured after the waste is mixed as certain rates and water content was controlled by 55% and 60%. Variation of VS showed food waste in reactors of number 1, 2, 3, 4 and 5 was decomposed fully except reactor of number 6. Decomposition degree of VS in reactors of number 1, 2, 3 and 4 was not different high because Vinyl and plastic inserted played role bulking agent in reactor number 1, 2, 3 and 4. In reactors, maximum temperature indicated $57{\sim}59^{\circ}C$ and temperatures in reactors 1, 2, 3 and 4 were higher and remained longer than in reactor 5 and 6 for 2~4 days. Variation of $CO_2$ was similar to that of VS. The reduction rate of water content was low because moisture generated by oxidation fever of microorganism did not evaporated well. pH was low in the beginning of the reaction however, as time passed, it increased slightly and remained regular pattern. EC and C/N showed the same pattern as pH. Settlement and weight reduction rates were similar to the factors above. Reactor 1, 2, 3, and 4 showed higher settlement and weight reduction rate than reactor 5 and 6.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.2
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• pp.41-48
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• 2020

In this study, organic carbon was extracted from the condensed water of food waste drying process to estimate the applicability as external organic carbon sources. The COD, TN, TP and TS of condensed water were 21,374 mg/L, 148 mg/L, 4.19 mg/L, and 455.7 mg/L, respectively. In addition, the content of biodegradable organics in condensed water was 47%. The fractional distillation and the vacuum evaporation were employed for extracting organic carbon. There were 8 extraction conditions, but 4 conditions were available for extraction. They were 1) 0mmHg, 110℃ 2) -600mmHg, 70℃ 3) -500mmHg, 80℃ 4) -600mmHg, 80℃. All 4 conditions showed the highest organic concentration and the highest quantity of organics when extracted 10% of initial volume. It was estimated that optimum conditions were 80℃, -600mmHg and 10% extraction. Then, extraction concentration, extraction quantity, extraction efficiency, extraction time, BOD/TCOD ratio, TVFAs/TCOD ratio and NH₃-N were 174,200 mg/L, 8,710 mg, 46%, 10 min, 0.97, 0.74 and 75.5 mg/L respectively. Therefore, the extracted organic carbon can be utilized as external organic carbon sources.

• Journal of the Korea Organic Resources Recycling Association
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• v.1 no.2
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• pp.227-235
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• 1993

This study was carried out to evaluate the possibility of composting for organic solid waste from restaurants and domestics. Small three vessels were prepared which were conditioned to semianaerobic, convectional and air-blowed type. During the experiment period for 4 months, the values of volatile solid(VS) %, moisture % and carbon/nitrogen (C/N) ratio of the wastes in the vessels were stabilized, 80 % to 40-50 %, 80 % to 48-55 % and 18 to 8-10, respectively. On the basis of VS % and C/N ratio, the reactions were more adaptable to 2nd order formula than to 1st order one, Reaction rate constant of the 3 vessels were estimated, $4.96{\times}10^{-5}(day^{-1})$ in the semianaerobic type, $5.82{\times}10^{-5}(day^{-1})$ in the convectional type and $8.42{\times}10^{-5}(day^{-1})$ in the air-blowed type on VS. Compared reaction rate constants(k), it can be said that composting period shorten if air is supplied artificially and that vessels simular to those of this study are useful for household organic waste at the backyards.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.2
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• pp.112-117
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• 2007

This study aims to develop an alternative energy like oil made from marine organic waste by marine products waste, spent fishing nets. There are already many commercial examples and case studies based on the petroleum industry-refuse plastic or refuse tire, however, it is rare that a research developing alternative energy from food waste and organic waste. Therefore, this study investigated the oil made from thermal decomposition under the high temperature and high pressure condition, and examined the possibility for commercial use by testing its own characteristics. A bio-oil from thermal decomposition at $250^{\circ}C$ and 40 atm was hard to remove impurities because of its high viscosity, showed lower caloric value than heavy oil, and generated various gases which were not appropriate for the use of fuel. It is noticeable that thermal decomposition was occurred at $250{\pm}5^{\circ}C$ using steam pressure, which much lower compared to the existing method of thermal decomposition, more than $500^{\circ}C$. Since the high viscosity of bio-oil, it is necessary a further study to use as liquid fuel.