• Journal of Biosystems Engineering
• /
• v.23 no.1
• /
• pp.31-48
• /
• 1998

가축분뇨, 음식쓰레기 둥의 유기성 고형 폐기물의 퇴비화처리 과정의 성능 향상과 암모니아 가스 발생을 저감화 하려는 연구의 일환으로서 파이로트 규모의 원통형 회분식 분해조 및 숙성조를 설계, 제작하여 퇴비화 성능과 탈취 효과를 분석하였다. 고형퇴비화 처리에 미치는 주요요인은 초기재료의 수분, 탄질비, 수소이온농도, 발효온도 및 통기조건 등이다. 돈분에 부자재인 톱밥을 혼합하여 초기 재료의 수분, 탄질비, 수소이온농도 등을 동일한 재료로서 같은 수준에 유지하고 연속통기와 간헐통기 방식으로 퇴비화하는 동안에 분해 및 숙성단계의 부위별 발효온도의 변화, 산소흡수 및 탄산가스 배출농도의 변동, 평균통기량, 재료의 평균온도 변화, 암모니아가스 배출농도의 변화 등을 분해 및 숙성 전기간을 통해 측정하고 초기재료와 숙성재료의 주요 이화학적 성분을 분석하여 퇴비화 성능과 회비 탈취 효율을 비교하였다. 주요 연구결과는 다음과 같다. 1. 숙성과정 8일 이후의 암모니아가스 탈취효율은 연속통기법이 90%이고, 간헐통기법이 70%였으며, 분해 및 숙성과정의 발효온도, 탄산가스 발생, 암모니아가스 배출농도 및 숙성회비의 성분 둥의 결과로서 판단할 때 에 퇴비 화 소요기 간은 6주간이었다. 2. 탄산가스 배출농도 변화로서 간헐통기 퇴비화 방식은 연속통기법에 비하여 분해과정이 7일 정도 빠르고, 숙성과정이 10일 정도 단축되었으며 암모니아가스 농도도 적게 나타나고 있었다. 3. 퇴비화 분해과정이 지난 후 숙성과정 도입단계에서 퇴비재료의 혼합 교반에 따른 재료의 고온상승으로 인한 암모니아가스의 고농도화 현상의 억제대책이 필요하다고 판단되었다.

• Journal of the Korean Wood Science and Technology
• /
• v.47 no.4
• /
• pp.393-407
• /
• 2019

In this study, we prepared lignocellulosic artificial soil that contains Bacillus subtilis (peat moss/perlite/ steam-exploded oak wood/microbial culture = 3:1:3:3, w/w/w/w) for use in the restoration of damaged soil areas. The prepared lignocellulosic artificial soil was mixed with soil at ratios of 0%, 25%, 50%, 75%, and 100%. These mixed soils were then applied to fields, and the resultant physicochemical properties and their effects on the plant growth of Lespedeza cyrtobotrya were observed. The mixture of the prepared artificial soils (mixed at ratios of 25%-100%) with soil had a bulk densities of <$0.04g/cm^3$, porosities of >85%, pH values between 4.3 and 4.7, electrical conductivities of <0.5 dS/m, C/N ratios between 15.0 and 26.5, organic matter content between 23.6% and 43.2%, and bacterial densities between $157{\times}10^6$ and $624{\times}10^6CFU/g$. In addition, the prepared artificial soils mixed with soil at ratios of 25%-50% exhibited higher plant growth rates for L. cyrtobotrya compared with the control. Overall, we identified positive correlations between the plant growth of L. cyrtobotrya and soil bulk density, porosity, water-holding capacity, C/N ratio, organic matter, and bacterial densities.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.6 no.2
• /
• pp.31-44
• /
• 1998

Mixtures of hog manure slurry and sawdust were composted by an intermittent aeration method to verify the performance evaluation of pilot-scale reactor vessels during composting high rate (decomposition) process. Instrumentation was designed to measure temperatures in compost, oxygen and carbon dioxide concentration, air flow rates, and ammonia gas emitted. It was found that ammonia concentration during composting high rate decreased more quickly to the allowable range of 34-40 ppm after 14days at near the optimal levels (II) than in the case of lower levels (I). The influence of the optimal levels (II) such as moisture content (55-65%), C/N ratio (20-40), pH (7-8) and temperature in compost (<$60^{\circ}C$) on the reduction of ammonia gas was considerable for commercial composting.

• Korean Journal of Organic Agriculture
• /
• v.20 no.2
• /
• pp.211-220
• /
• 2012

This study was conducted to evaluate soil nutrient concentrations and N uptake efficiency of paddy rice as affected by nutrient sources from 2009 to 2011. The treatments included chemical fertilizer, compost, oilcake, oilcake 2X, hairy vetch, vetch+rye, and control. Nutrient applications were made at rates equivalent to approximately 90 kg of actual N per hectare. Oilcake had the lowest C:N ratio from the raw materials, but compost had the highest C:N ratio of 34:1. Soil pH and concentrations of C, N, Ca, and Mg were unaffected by nutrient source treatments. N uptake efficiency was the greatest for oilcake-treated rice compared to those treated by NPK, hairy vetch, and compost in 2009 and 2010. Composttreated rice had the greatest N uptake efficiency in 2011 when the high amount of precipitation occurred.

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

• Korean Journal of Organic Agriculture
• /
• v.18 no.2
• /
• pp.245-255
• /
• 2010

The study was conducted to investigate the effects of organic fertilizers and mulches on the growth and $CO_2$ assimilation in MM.106 apple trees. Growth and $CO_2$ assimilation of MM.106 apple trees grown in a greenhouse were affected by the nutrient concentrations and carbon (C) and nitrogen (N) ratio in the raw materials of organic fertilizers and mulches. The optimum C:N ratios, which makes microorganism convert the organic N into the inorganic N, were obtained in the organic fertilizer, poultry litter, green compost, and grass clippings, resulting in increasing single shoot height, SPAD, and $CO_2$ assimilation. The SPAD and $CO_2$ assimilation were affected by the treatments 5 weeks after the treatments, and then the tree growth was affected by the treatments 6 weeks later. The most efficient tree growth and development were observed in the 10 to $15\;mg{\cdot}kg^{-1}$ of the inorganic N in a soil, and the N was strongly related to the tree growth and development.

• Journal of Animal Environmental Science
• /
• v.13 no.1
• /
• pp.13-20
• /
• 2007

Sawdust biofiltration is an emerging bio-technology for control of ammonia emissions including compost odors from composting of biological wastes. Although sawdust is widely used as a medium for bulking agent in composting system and for microbial attachment in biofiltration systems, the performance of agitated bed composting and sawdust biofiltration are not well established. A pilot-scale composting of hog manure amended with sawdust and sawdust biofiltration systems for practical operation were investigated using aerated and agitated rectangular reactor with compost turner and sawdust biofilter operated under controlled conditions, each with a working capacity of approximately $40m^3\;and\;4.5m^3$ respectively. These were used to investigate the effect of compost temperature, seed germination rate and the C/N ratio of the compost on ammonia emissions, compost maturity and sawdust biofiltration performance. Temperature profiles showed that the material in three runs had been reached to temperature of 55 to $65^{\circ}C$ and above. The ammonia concentration in the exhaust gas of the sawdust biofilter media was below the maximum average value as 45 ppm. Seed germination rate levels of final compost was maintained from 70 to 93% and EC values of the finished compost varied between 2.8 and 4.8 ds/m, providing adequate conditions for plant growth.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.22 no.1
• /
• pp.57-66
• /
• 2014

The present study was conducted to provide basic data for environmentally friendly treatment of manure using vermicomposting. This was done by investigating the influence of physiochemical property change during the composting period on the survival of earthworms after mixing cow manure in different levels (0(CRH0), 10(CRH10), 20(CRH20), 30(CRH30), and 40%(CRH40)) with the rice hull that is generally added for composting manure. As composting proceeds, earthworms were able to survive in all conditions after 3 weeks. In terms of the C/N ratio by treatment groups, the rice hull mix treatments were significantly higher than the CRH0 treatment. Among rice hull mix treatments, the treatments with 30~40% rice hull level (CRH30 & CRH40) showed the highest ratio out of all composting periods (p<0.05). The C/N ratio in the 3rdweek when earthworms started surviving was 23.26~34.44. As composting progressed, pH and electrolytic conductivity (EC) were the highest in the CRH0 treatment (p<0.05) and tended to decrease with higher proportion of rice hull in the mix. It was found that pH and electrolytic conductivity (EC) that earthworms start to survive are 7.58~7.74 and 0.41~1.17 mS/cm, respectively. To summarize, when composing cow manure with various levels of rice hull mix, all physiochemical property changes turned out to allow the survival of earthworms, but the results suggest that efficient vermicomposting requires the tests to examine the growth and reproduction according to the rice hull mix ratio.

• Korean Journal of Organic Agriculture
• /
• v.20 no.3
• /
• pp.357-368
• /
• 2012

This study was conducted to evaluate soil inorganic N concentrations and N uptake efficiency of sorghum ${\times}$ sudangrass hybrid (Sorghum bicolor (L.) Moench) as affected by organic nutrient sources from 2009 to 2011. The treatments included chemical fertilizer, compost, oilcake, alfalfa hay mulch, and control. Nutrient applications were made at rates equivalent to approximately 210 kg of actual N per hectare. The precipitation during the growth period from May to September was higher in 2011, followed by 2009, and 2010. Oilcake had the lowest C:N ratio in the raw materials. Compost treatment slowed N-mineralization rate in soil during the measured years. Soil mineral nutrition and dry matter production were not consistently affected by treatments, but the dry matter production was negatively correlated with the amount of precipitation from May to September for three years. Chemical fertilizer treatment increased N efficiency in plants in the first two years, observing with lower N efficiency in plants treated with compost for 3 years. Increased precipitation from June to August improved N efficiency in sudangrass plants treated with compost but reduced the efficiency with the chemical fertilizer. Total dry matter production and N efficiency in plants were not affected by the C:N ratio of the raw materials rather than weather condition.

• Journal of Wetlands Research
• /
• v.16 no.4
• /
• pp.443-452
• /
• 2014

Feces contain nutrients such as nitrogen and phosphate, potassium and research of the impact on the environment from feces is very diverse. However, despite the importance of mammals to environment, studies of mammals into the terrestrial ecosystems are rare. Korean water deer (Hydropotes inermis) is an endemic species of Korea and China, and we conducted on factor of plant growth in relation to feces of Korean water deer depending on land use patterns. The analysis of growth, biomass and C/N ratio of Zea mays, amount of feces and land use patterns are strongly affecting the C/N ratio and growth of the Zea mays. The quantity of the feces also influences the growth of plants instead of the land use patterns. Furthermore, the feces of Korean water deer have a lower C/N ratio than that of other animals' feces. Being the process of composting, it is able to serve a suitable fertilizer for a crop growth. In this study, we investigated the impact of feces into the environment in the terrestrial ecosystems and we were able to provide the basic data to the resources of an efficient scheme of animal feces. Further research is needed to quantify the materials amongst the plant, soil and animal, and to understand the relationship ecosystem.