• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.92-96
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• 2003

The on-site sewage sludge vermicomposting equipment was designed and evaluated on the batch and continuous tests. The vermicomposting equipment was designed to consider the mechanization as well as automation. In terms of performance evaluation of equipment with continuous experiments, the highest treatment rate was found in the condition of 5mm in particle size and 10mm in e feeding height. Also, 20~25kg of earthworm per 50kg of sewage sludge was the most appropriate density of earthworm. In addition, the most effective separation of cast was found when the earthworm breeding box height was 80cm. The performance evaluation on equipment allowed the establishment of earthworm composting capacity of 2ton per a day with a size of $5{\times}3{\times}1m$ and the automatic control devices.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.51-62
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• 2009

This study was carried out development a new composting system to lower copper and zinc concentration in plg sludge compost and conduct an inquiry into the possibility of crop cultivation. The concentrations of nitrogen, phosphorus and pH averaged 4.4%, 6.3% and 7.57, respectively, which were higher concentrations than in commercial organic fertilizers, and the concentrations of copper and zinc averaged 805 and 1,704 mg/kg, respectively, which were beyond the heavy metal concentration limit in byproduct compost. Hydrated citric acid I lowered the concentrations of copper and zinc by 58% and 97%, respectively and hydrated oxalic acid II lowered the concentrations of copper and zinc by 48% and 56%, respectively in pig sludge compost. Lower concentrations of copper and zinc in pig sludge resulted from the enhanced hydrated-citric acid concentration in organic acid solution mixed with distilled water. The concentrations of copper and zinc were 330, and 41 mg/kg in the pig sludge treated with 100% hydrated citric acid. Agitation composting system stabilized the compost earlier than the stationary composting system, in which the stabilization condition was confirmed by higher temperature by $4^{\circ}C$ at highest temperature and 7 days earlier cooling down after highest temperature. The levels of germination index (G.I) 80 were obtained 15 and 20 days after composting in agitation and stationary composting system, respectively. The concentrations of copper and zinc were 2.4 and 4.26 mg/kg respectively in soils amended with pig sludge compost after removing process of heavy metals by citric acid, but 8.0 and 22.37 mg/kg, respectively in soils amended with Pig Sludge. The concentrations of heavy metals was highest in com cultivated in soils amended with pig sludge. The copper and zinc concentrations In corn leaves were 75.2 and 50.56 mg/kg respectively, which were 4 and 2 fold higher than the com cultivated in soils amended with pig sludge compost after heavy metal removing process by hydrated citric acid.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.303-311
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• 1996

The microflora changes of 10 water-controled treatments combined with livestock manures(pig, chicken) and bulking agents(sawdust, paper sludge) were investigated. The B/F values of the P-1 and C-1(65%, $H_2O$) treatments were 3571 and 5400 respectively, but those of the P-4 and C-4(50%, $H_2O$) treatments showed very low values, 667 and 334, respectively. The B/F values tended to increase with higher water content of the treatments. In the composting processes, the successions of microflora, adapting the compost environments, took place via fluctuating temperature. In the high temperature period, the numbers of mesophilic bacteria and fungi decreased, but that of the spore forming bacteria increased. However, the number of mesophilic bacteria inereased during the cold period. The B/F values of compost ranged 25-300, which indicates a decrease in the quantity of bacteria. The time required for the temperature of compost to reach $60^{\circ}C$ showed different patterns. There was no pathogenic microorganism in the treatments which reached a high temperature in a short period of time, but, in the treatments which reached a high temperature over a Long period of time, the pathgenic microorganism was not still alive.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.4
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• pp.63-73
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• 2015

This study was carried out to evaluate the change of heating value of cow manure by applying pre-treatment process. Three types of treatment precess; Composting, Dry anaerobic digestion and Physical compression were applied as a pre-treatment method. Composting and anaerobic digestion of cow manure were cause of caloric value reduction of the cow manure. The heating value of cured compost was 5% lower than that of initial composting material. The heating value of dry anaerobic digestion residue was 25.7% lower than that of fresh cow manure. By physical compression of cow manure, heating value and VS/TS ratio (Volatile solids/Total solids ratio) of compressed cow manure were higher than that of fresh cow manure. On the other hand, heating value and VS/TS ratio of leachate generated by compression process were lower than those of fresh cow manure.

• 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.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.2
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• pp.19-29
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• 1994

A large volume of paper mill sludge(PMS) is produced every day from paper industries after treatments of waste water and it costs too much to dispose of the sludge. Since PMS consists mostly of biodegradable organic matter, cellulose, it is desirable to recycle it by proper treatments such as composting. In this study, experiments were conducted using a small scale reactor(12l) to establish optimum conditions for efficient composting of PMS of which initial pH, C/N ratio, and moisture content were 7.1, 28~30, and 60~65%, respectively. No heavy metals such as mercury, cadmimum, and lead were not detected in the PMS. Various levels of forced aeration, 1 minute aeration per every 30, 60, 120, 240, and 480 minutes were applied and 1 minute aeration per 60 and 120 minutes found to be proper for composting of 8l PMS in this system. Relationship between $CO_2$ production and temperatures was positively correlated with r> 0.82 suggesting that the normal decomposition of PMS by microorganisms occurred. However, under the condition of aeration interval over than 240 minutes, a negative relationship between two parameters was found indicating the occurrence of abnormal(maybe anaerobic) degradation. The amount of added nitrogen also affected composting of PMS resulting in the increase of $CO_2$ production and temperature. Semi-field tests using 100kg PMS in a static pile sysem showed that PMS could be composted efficiently under optimal environmental conditions. The parameters determining efficiency of composting such as C/N ratio, aeration, moisture content, and pH need to be monitored.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.1
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• pp.56-64
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• 2001

Composting of livestock feces is economic and safe process to decrease the possibility of direct leakage of organic pollutants to ecosystem from commercial and environmental point of view. This study was conducted with three different experiments related to composting of livestock feces. The purpose of experiment 1 was to investigate changes of characteristic of compost pile during composting period by low temperature in cold season. To compare composting effect of experimental compost pile and control pile exposed in cold air, experimental compost piles were warmed up by hot air until their temperatures were reached at $35^{\circ}C$. Sawdust, Ricehull and Ricestraw were mixed with livestock feces as bulking agent. The highest temperatures of compost pile during composting period were in sawdust, rice hull, rice straw, and control were $75^{\circ}C$, $76^{\circ}C$, $68^{\circ}C$, $45^{\circ}C$ respectively. Moisture content, pH, C/N and volume of compost were decreased during composting period. Experiment 2 was carried out to study utilization effect of compost by plant. A corn was cultivated for 3 years on fertilized land with compost and chemical fertilizer. The amount of harvest and nutrition value of corn were analyzed. In first year of trial, the amount of harvest of corn on land treated with compost was lower by 20% than that of land treated with chemical fertilizer. In second year, there was no difference in yield of com between compost and chemical fertilizer. In third year, the yield of com on land fertilized with compost was much more than that of land fertilized with chemical fertilizer. The purpose of experiment 3 was to estimate the decrease of malodorous gas originating from livestock feces by bio-filter. Four types of bio-filters filled with saw dust, night soil, fermented compost and leaf mold were manufactured and tested. Each bio-filter achieved 87-95% $NH_3$ removal efficiency. This performance was maintained for 10 days. The highest $NH_3$ removal efficiency was achieved by leaf mold on the first day of operation period. It reduced the concentration of $NH_3$ by about 95%. Night soil and fermented compost showed nearly equal performance of 93 to 94% for 10 days from the beginning of operation. The concentration of hydrogen sulfide and methyl mercaptan originating for compost were equal to or less than $3mg/{\ell}$ and $2mg/{\ell}$, respectively. After passing throughout the bio-filter, hydrogen sulfide and methyl mercaptan were not detected.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.05a
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• pp.109-110
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• 2004

국가적 과제인 음식물쓰레기 발생량을 저감시킬 수 있는 ‘지렁이를 이용한 음식물쓰레기 퇴비화’를 실천하고 있는 가정을 대상으로 설문조사를 함으로써 도시가정에서의 지렁이퇴비화 확산가능성을 확인할 수 있었다. 그러나 지렁이 사육방법에 대해 충분히 숙지하지 못함으로써 운영상에 어려움이 많았으며, 이에 대한 개선책으로서 일반인을 위한 지렁이퇴비화 지침서 제작.배포 및 상호간의 정보공유를 위한 장의 마련이 필요하였다.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.294-296
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• 2007

본 논문은 고온 고압 수증기를 활용한 유기성 폐기물의 가수분해현상과 이를 이용한 퇴비 등의 재활용 방안을 제시한다. 사료화의 경우는 3.27 기압 $135^{circ}C$ 전후의 포화수증기로 교반처리하여 영양소 파괴를 줄이고 멸균 및 가수분해가 일어나게 하여 소화가 잘되는 사료를 만들 수 있고, 퇴비화의 경우는 16기압. $200^{circ}C$ 전후의 포화수증기로 교반처리하여 가수분해, 산가수분해, 열분해 및 탄화가 일어나도록 하여 목초액과 활성탄을 함유한 보온성, 보비성 및 통기성이 양호한 퇴비를 만든다. 응축수는 액비로 사용가능하므로 완전 재활용이 가능하다.

• Monthly Duck's Village
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• s.195
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• pp.20-23
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• 2019

환경부 고시인 '퇴비액비화기준 중 부수도 기준 등에 관한 고시'에 따라 내년 3월 25일부터 모든 축산농가에 대해 퇴비 부숙도 검사가 의무화된다. 3월 25일 이후에는 반드시 부숙 과정을 거쳐 축산 분뇨를 배출해야 하며, 허가대상 농가의 경우 6개월에 한 번, 신고대상 농가의 경우 1년에 한 번 분석시험기관에 가축 분뇨의 부숙 측정을 의뢰 분석해야 한다. 이를 어길 시 부숙도 부적합 정도에 따라 최소 50만원에서 최대 1,000만원의 과태료를 받게 된다. 축산농가들의 이해를 도와 실질적으로 대비할 수 있도록 퇴비 액비 부숙도 검사 내용과 전국의 부숙도 측정 기관 등을 소개한다.