• Journal of Environmental Health Sciences
• /
• v.26 no.3
• /
• pp.1-10
• /
• 2000

Although microorganisms play an important role in composting process, researches on the effective microorganism (EM) in composting process are rarely reported. In this study, three stages of work performed 1) investigation of composting facility 2) sample collection and isolation of the EM 3) lab-scale composting by seeding the isolated EM. For this, purpose, physical, chemical, and biological characteristics, such as temperature, moisture content, organic matter, pH population of microorganism, etc., were investigated during the process and the results were compared with those of a control(non-seeded). In the composting facility, the most active degradation of food waste was suppsed to occur in 10-11th day of composting by observing the temperature and CO2 emission. The population of bacterial and fungi was highest in thermophilic stage. Meanwhile that of actinomycetes and yeast was relatively uniform during the process. In the lab-scale test, the thermophilic stage was maintained longer(more than 9 days in 17 days of experiment) in the seeded which was favored for the high reduction of organic matter and moisture. Reduction rates of lipids and salinity were also increased in the seeded. It confirmed these results that the population of microorganisms in the seeded was observed higher in several orders than the control. However, pH of the seeded was maintained as low as about 4.5 throughout the experiment except the final period of the process. Meanwhile, pH of the control rose in the early stage of the experiment. This was probably due that the seeded microorganisms collected from the composting facility was adapted to the low pH environment.

• Korean Journal of Soil Science and Fertilizer
• /
• v.50 no.6
• /
• pp.623-633
• /
• 2017

Food waste has been recognized as a organic sources for composting and many research was conducted to efficiently utilize or treat. This study was to evaluate a feasibility for producing food waste compost under co-composting with mixture of food and animal waste. The mixing ratio of food and animal waste was 35% as main material, which additionally mixed 30% of sawdust for co-composting. Total days of composting experiment were 84 days and each sub samples were collected at every 7 days from starting of composting. Results showed that inner temperature in composting was rapidly increased to $70{\pm}4^{\circ}C$ within 3~5 days depending on mixing animal waste of cattle, pig, and chicken base compared to sole food waste base. Expecially, the CN ratio in the mixture of food and pig water was the highest (16.2) among compost. After finishing composting experiment, maturity was evaluated with solvita and germination test. Maturity index (MI) of the mixture of food and animal waste was ranged between 6~7, but was 3 in sole food waste. Calculated germination index (GI) was at the range of about 100 irrespectively of mixing of food and animal waste. However, NaCl content and heavy metal as Cr, Cu, Ni, Pb, and Zn contents was increased in the mixture of food and animal waste. which was the highest in compost mixed the food and pig waste. Both MI and GI showed that manufactured fertilizer was suitable for fertilizer criteria while sole food waste was not adequate for composting due to composting periods. Overall, mixing the food and animal waste can be utilized for improving compost maturity, but more research should be conducted to make high quality of food waste compost with animal waste in agricultural fields.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1996.06c
• /
• pp.722-727
• /
• 1996

A simple compost windrow-forming car and a compost tuner were developed at the aim of low cost manure management systems. The developed compost windrow- forming car is possible windrows formation at a short time. In order to be pulverized and mixed by upper and lower beaters at the windrow-forming, the condition of air and the mixing of materials to play a major role in composting is filled. This car can also utilized for a manure spreader by folding the windrow-forming cover. The developed compost turner is a type equipped with tractor rear-right side. Main specifications are 2.5m working width, overall length 3.3m and 45degrees conveyer inclination angle, 2 beaters for mixing and pulverization are equipped in front parts. Windrows of 2.5m width and 1.5m height are turned at the speed of 4.5-5.1m/min. In accordance with the above, by combining the compost windrow-forming car and the compost turner, a simple composting system for each farmer could be constructed by the low c st.

• Journal of Animal Environmental Science
• /
• v.4 no.1
• /
• pp.55-61
• /
• 1998

Cow feces excreted in cold season should be managed and composted properly, because the composted feces is distributed to pasture or cultivated land as a fertilizer in spring. Generally it is admitted that the effect of composting is suppressed by low temperature in cold season. In this study, composting piles were warmed by hot air until temperature of compost piles were reached at 35∼40$^{\circ}C$, to compare composting effect of experimental compost pile to control pile exposed in cold air. Some results obtained from the experiment during composting of cow feces mixed with bulking agent provide a possibility of active composting of organic matters in cold season. The biodegradation ratios of organic matter during composting in four types of composts were 10.2% for the rice straw, 7.7% for the rice hull, 6.4% for the sawdust and 4.3% for the control. The highest temperatures of compost piles during composting period were 76$^{\circ}C$ in sawdust, 80$^{\circ}C$ in rice hull, 68$^{\circ}C$ in rice straw, 45$^{\circ}C$ in control. Moisture content, pH, C/N, volume of compost were decreased during composting period, but EC value was increased with ionization of organic molecular by fermentation.

• Environmental Engineering Research
• /
• v.25 no.2
• /
• pp.258-265
• /
• 2020

Heavy metal removal by using porous mineral adsorbents bears a great potential to decontaminate sludge compost, and natural zeolite (NZ), artificial zeolite (AZ), and expanded perlite (EP) seem to be possible candidates for this purpose. A composting experiment was conducted to compare the efficiency of those adsorbents for removal of iron (Fe), manganese (Mn), chromium (Cr), copper (Cu), zinc (Zn), nickel (Ni), and lead (Pb) from sewage sludge compost with no adsorbent amendment. For this purpose, 10 g of NZ and AZ and 5 g of EP was filled in a small bag made from non-biodegradable synthetic textile and was separately mixed in composting piles. The bags were separated from compost samples at the end of the experiment. AZ and NZ exhibited different reduction potentials depending on the type of heavy metal. AZ significantly reduced Cr (43.7%), Mn (35.8%), and Fe (29.9%), while NZ more efficiently reduced Cu (24.5%), Ni (22.2%), Zn (22.1%), and Pb (21.2%). The removal efficiency of EP was smaller than both AZ and NZ. The results of this simultaneous composting and metal removing study suggest that AZ and NZ can efficiently bind metal during composting process.

• Korean Journal of Soil Science and Fertilizer
• /
• v.33 no.5
• /
• pp.361-368
• /
• 2000

This study was carried out to investigate the influence of artificial zeolite on the change of temperature, gas emission, water content and chemical properties during the composting process with the mixture of animal feces, broken bark and extruded rice hull. Artificial zeolite was added 0, 0.5, 1, 3 and 5% volume of the raw composting material, and proceeded 1.2m every day with mobile stacking escalator. Temperature was increased, and water content was decreased in the composting pile by addition of artificial zeolite. This caused to accelerate decomposition of organic matter during composting. $NH_3$ was emitted the highest at 6th day after stacking, then decreased gradually. And addition of artificial zeolite caused to decrease greatly in $NH_3$ emission from composting pile. As result of this, content of nitrogen in the compost was increased by addition of artificial zeolite. Emission of $CH_4$ was the highest at early stacking stage, and that was decreased drastically at 8th day. Emission of $CH_4$ was also decreased greatly by addition of artificial zeolite at 5th days after stacking. It may be resulted from adsorption of $CH_4$ into the molecular sieve structure of artificial zeolite and low water content by high temperature fermentation.

• Korean Journal of Soil Science and Fertilizer
• /
• v.50 no.6
• /
• pp.588-597
• /
• 2017

Food waste has been recognized as a critical problem in Korea and many research was conducted to efficiently reutilize or treat food waste. Main purpose of this research was to evaluate a feasibility for producing fermented organic fertilizer with mixture of earthworm cast (EC). Four different treatments were mixed with food waste and EC at the rate of 0, 10, 20, and 30%, respectively. Total days of composting experiment were 84 days and each sub samples were collected at every 7 days from starting of composting. Results showed that inner temperature in composting was increased to $70{\pm}4^{\circ}C$ within 5~10 days depending on mixing ratio of EC. Among different treatment, the highest increase of inner temperature was observed in treatment mixed with food waste and EC 30%. After finishing composting experiment, maturity was evaluated with solvita and germination test. Maturity index (MI) of each treatment was ranged between 5~7 indicating that manufactured fertilizer was curing or finished stage. Calculated germination index (GI) was at the range of 104~116 depending on mixing ratio of EC. Both MI and GI showed that manufactured fertilizer was suitable for fertilizer criteria while control (FW only) was not adequate for composting. Overall, earthworm cast can be utilized for improving compost maturity by mixing with food waste and more research should be conducted to make high quality of food waste compost with earthworm cast in agricultural fields.

• Journal of Animal Environmental Science
• /
• v.13 no.2
• /
• pp.121-128
• /
• 2007

To develop the composting system to reduce the use of bulking agent, continuous composting was performed with farmer scale facility, The plant comprises a horizontal pit reactor closed inside a greenhouse and equipped with a turning machine moving on rails. The pit was 9m wide and 50m long and the maximum height of loaded materials was $1.8m^2$. The materials remained in the reactor for 5 months. During the composting process, temperature and water content measured and water balance was evaluated. The reaction temperature of composting was changed $30{\sim}50^{\circ}C$ and high in the middle and low in under composting piles. The moisture contents of the compost were approximately 70% during the experiment. The amount of effluent was 10.6% and $3.16m^3$ of pig slurry per $1m^3$ of bulking agent was treated during continuous composting process. BOD and SS reduction of the effluent in continuous composting was 86.5% and 92.2%, respectively. Indoor relative humidity in night time was changed between 80 and 100%.

• Korean Journal of Soil Science and Fertilizer
• /
• v.35 no.2
• /
• pp.127-135
• /
• 2002

This study was conducted to investigate the physico-chemical and microbiological properties in profile depth during composting process with different turning times when pig manure was composted with ground rice hulls at the rate of same for the promotion of the composting. The moisture contents, C/N rate and pH value decreased according to composting progresses as run into turning times, but increased those inside layer of the pile. $NH_4-N$ and $NO_3-N$ contents were high in the outer layer mostly, as the result the $NH_3$ flux was high in there, but it decreased as composting progresses. The number of aerobic bacteria were $10^7{\sim}10^9\;cfu\;g^{-1}$, increased as the turning times, the number of their showed high in the outer layer. The number of fungi were $10^2{\sim}10^4\;cfu\;g^{-1}$ at the early period of composting, but did't almost survive inside layer as composting progresses. The number of cellulose decomposer and thermophilic bacteria were $10^6{\sim}10^7\;cfu\;g^{-1}$ and $10^6{\sim}10^9\;cfu\;g^{-1}$, respectively, they showed high inside layer of the pile. Therefore, the turning of composting can reduce the change difference of microorganisms in the pile. Turning frequence for the promotion of composting showed approximately 2~3 times.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.12 no.4
• /
• pp.72-80
• /
• 2009

The main purpose of this study is as follows : Finding a solution for fresh wood chips to be used as an alternative growing-media through a study of the formation method of a compost base that is applicable on both construction site and composting factory to ferment fresh wood chips produced from construction site as well as a study on adjuvant or secondary materials. The result from the experiment plot using wood chips sized 50mm or less, manure and fertilizer mixed manure as a source of nitrogen to compost fresh wood chips has shown that the temperatures 9days and 3days after the beginning of the experiment reached to $49.0^{\circ}C$ and $40.4^{\circ}C$ respectively, the heating duration was 7days and 4days respectively, and the C/N ratio was 26.5 and 25.3, each satisfying the standard for composted manure (25.0~40.0). Also, the other result from another experiment plot using mixture of sandy soil and microorganism as an inoculation source of microorganism has shown that the temperature 10days after the beginning of the experiment reached to $67.6^{\circ}C$ and lasted 16days. The experiment plot using sandy soil has shown the highest figure of $5.3{\sim}108$ CFU/g in terms of number of microorganism. The result from the experiment plots for on-site composting of fresh wood chips have shown that the experiment plot that used sandy soil with fertilizer due to supply restriction of manure as a nitrogen source in construction site reached the high temperature of $54.7^{\circ}C$ after 3days of experiment beginning and maintained heating state for 17days and reached 30.6 of C/N ratio, satisfying the standard for composted manure.