• Asian-Australasian Journal of Animal Sciences
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• v.29 no.5
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• pp.753-758
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• 2016

Moisture content influences physiological characteristics of microbes and physical structure of solid matrices during composting of animal manure. If moisture content is maintained at a proper level, aerobic microorganisms show more active oxygen consumption during composting due to increased microbial activity. In this study, optimum moisture levels for composting of two bedding materials (sawdust, rice hull) and two different mixtures of bedding and beef manure (BS, Beef cattle manure+sawdust; BR, Beef cattle manure+rice hull) were determined based on oxygen uptake rate measured by a pressure sensor method. A broad range of oxygen uptake rates (0.3 to 33.3 mg $O_2/g$ VS d) were monitored as a function of moisture level and composting feedstock type. The maximum oxygen consumption of each material was observed near the saturated condition, which ranged from 75% to 98% of water holding capacity. The optimum moisture content of BS and BR were 70% and 57% on a wet basis, respectively. Although BS's optimum moisture content was near saturated state, its free air space kept a favorable level (above 30%) for aerobic composting due to the sawdust's coarse particle size and bulking effect.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.113-118
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• 2009

We investigated the structure of bacterial communities present in livestock manure-based composting processes and evaluated the bacterial succession during the composting processes. Compost samples were derived separately from swine manure, dairy manure and sewage sludge. The structure of the bacterial community was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) using universal eubacterial primers. The genus Bacillus and related genera were mainly detected following the thermophilic composting phase of swine and dairy manure composts, and the members of the phylum Bacteroidetes were mainly detected in the cattle manure waste-based and sewage sludge compost. We recovered and sequenced limited number of the bands; however, the PCR-DGGE analysis showed that predominant diversities during the composting processes were markedly changed. Although PCR-DGGE analysis revealed the presence of different phyla in the early stages of composting, the members of the phylum Firmicutes and Bacteroidetes were observed to be one of the predominant phyla after the thermophilic phase.

• Environmental Engineering Research
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• v.18 no.3
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• pp.177-189
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• 2013

Studies were carried out on the speciation of heavy metals (Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr) during rotary drum composting of water hyacinth (Eichhornia crassipes) for a period of 20 days. Five different proportions of cattle manure, water hyacinth and sawdust were prepared for composting. This study concluded that, rotary drum was very efficient for the degradation of organic matter as well as for the reduction of mobility and bioavailability of heavy metals during water hyacinth composting. The results from the sequential extraction procedure of heavy metals shows that rotary drum composting changed the distribution of five fractions of Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr. The highest reduction in the bioavailability factors of Pb and Cd was observed during the process. The total concentration of Cu, Cr, and Cd was very low compared to the other metals (Zn, Mn, Fe, Ni, and Pb); however, the percentage of exchangeable and carbonate fractions of these metals was similar to other metals. These results confirmed that the bioavailability of metals does not depend on the total concentration of metals. From this study, it can be concluded that the addition of an appropriate proportion of cattle manure significantly reduced the mobile and easily available fractions (exchangeable and carbonate fractions) during water hyacinth composting in rotary drum.

• Journal of Animal Environmental Science
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• v.2 no.2
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• pp.123-133
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• 1996

Recently, a greater interest has been placed on the methods of acration control for management of maloders during composting. This study was performed to evaluate the influence of the intermittent aeration method on the composting temperature and chemical components. Combinatoins of cattle manure and rice hulls were placed on a batch composter(3,150-L size) practically designed. The chemical properties of the produced compost were suitable for plant growth, when composting temperature was maintained in the range from 45 to $66^{\circ}C$ for 42 days. It should be noted that cooling effect of intake air was not significant because air temperature was as high as $30^{\circ}C$. Heat and aeration loss from the composter did not affect biomass decomposition by microbes during composting. Mixtures of materials with C/N ratios higher than 30 required longer composting period.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.594-598
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• 2016

We studied airborne contaminants (airborne particulates and odorous compounds) emitted from compost facilities in South Korea. There are primarily two different types of composting systems operating in Korean farms, namely mechanical aerated pile composting (MAPC) and aerated static pile composting (SAPC). In this study, we analyzed various particulate matters (PM10, PM7, PM2.5, PM1, and total suspended particles), volatile organic compounds and ammonia, and correlated these airborne contaminants with microclimatic parameters, i.e., temperature and relative humidity. Most of the analyzed airborne particulates (PM7, PM2.5, and PM1) were detected in high concentration at SAPC facilities compered to MAPC; however these differences were statistically non-significant. Similarly, most of the odorants did not vary significantly between MAPC and SAPC facilities, except for dimethyl sulfide (DMS) and skatole. DMS concentrations were significantly higher in MAPC facilities, whereas skatole concentrations were significantly higher in SAPC facilities. The microclimate variables also did not vary significantly between MAPC and SAPC facilities, and did not correlate significantly with most of the airborne particles and odorous compounds, suggesting that microclimate variables did not influence their emission from compost facilities. These findings provide insight into the airborne contaminants that are emitted from compost facilities and the two different types of composting agitation systems.

• Resources Recycling
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• v.8 no.4
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• pp.39-44
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• 1999

Nightsoil and brewery sludges usually contain a high concentration of organic matters. A composting study using reactors was carried out for the recycle of brewery wastewater sludge and nightsoil treatment sludge, which have been landfilled. A good composting process was obtained with a sludge mixing ratio of 1:1 and injual pH had no effect on temperature increase related to microbial activity. The injtial C/N ratio at approximarely 15 decreased to 13 without the increase in pH.. It was found that agitation of one time a week provided the most effective composting process.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.403-410
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• 1996

Variations of temperature and physicochemical environment during composting of a mixtures(2:1, v/v) of cattle manure and rice hulls(CMR) in two different composting methods, static windrow(SW) and aerated static pile system(ASPS), were monitored for evaluating the efficient composting system in greenhouse. The pH of composting materials increased to around 8.9 initially, then decreased and stabilized slowly to the neutral value. Composting materials in ASPS showed a rapid stabilization in pH value from the 4th week comparing to the speed in SW. Thermophilic stage for ASPS Lasted at 3 week whereas 6 weeks for WS. Required time to get thermophilic zone in compost was shorter in ASPS than in WS. Reduction rate in total carbon(T-C) was higher in ASPS than in WS. Organic matter was reduced more rapidly in ASPS than in SW showing 9 percent difference after the 6th week. Total nitrogen(T-N) increased while composting process, showing 9 percent after 6th week in WS and 1.8 percent after 7th week in ASPS. C/N ratio was stabilized after 6th week showing 17 and 21 level in WS and ASPS each. Quantity of ash and mineral content increased during composting in both system, showing higher content in ASPS. Composting process by intermittent, aerated static pile system in greenhouse had a significant effect on the reduction of required period for composting.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.2
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• pp.93-100
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• 2001

To study the possibility of agricultural utilization of seafood processing wastewater sludges, the change of temperature, decreasing ratio of weight generation quantity of $CO_2$ and $NH_3$, and contents of inorganic elements for composting by adding different rates of zeolite and livestock manure to seafood processing wastewater sludges were investigated. Changes of temperature, decreasing ratio of total weight and generation quantity of $CO_2$ were not little different with increasing addition rates of zeolite for composting. But the less addition quantity of livestock manure is, the higher were temperature and decreasing ratio weight for composting. Ceneration quantity of $NH_3$ in composting materials as adding zeolite ti 5, 10 and 20% and livestock manure to 50, 65 and 80% were 68, 61 and $46mg/kgvs{\cdot}hr$, respectively, for composting periods. So, $NH_3$ generated little quantity as much as possible addition of zeolite and manure. Contents of T-C and T-N little decreased and C/N ratio little increased after composting than before. Content of $P_2O_5$, $K_2O$, CaO also increased a little, that of MgO is not different and that of Mn decreased very sharply in all conditions after composting than before.

• Clean Technology
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• v.23 no.4
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• pp.345-356
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• 2017

The composting is a biological process that converts organic matter into useful resources such as fertilizers. It is a continuous transition of microbial communities to adapt changes in organic matter and environmental conditions (carbonation rate, temperature, humidity, oxygen supply, pH, etc.). Most of the composting plants are located in the proximity of the residential areas. It is a general scenario where government authorities receive complaints from the local residents due to release of odor from the composting, and has become a social problem in Korea. Identification of dominant microorganisms, understanding change in microbial communities and augmentation of specific microorganism for composting is vital to enhance the efficiency of composting, quality of the compost produced, and reduction of odor. In this paper, we suggest the optimum operation conditions and methods for compost depot to reduce odor generation. The selection of the appropriate microorganisms and their rapid increase in population are effective to promote composting. The optimal growth conditions of bacteria such as aeration (oxygen), temperature, and humidity were standardized to maximize composting through microbial degradation. The use of porous minerals and moisture control has significantly improved odor removal. Recent technologies to reduce odor from the composting environment and improved composting processes are also presented.

• Environmental Engineering Research
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• v.25 no.3
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• pp.299-308
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• 2020

Composting is among the most effective integrated waste management strategies used to recycle sewage sludge (SS) waste and generate a useful product. An encapsulated lifting system is a relatively new industrial-scale composting technology. The objective of this study was to evaluate the effectiveness of composting dewatered stabilized SS mixed with green waste using this new technology. The composting process was monitored by changes in the physico-chemical properties, UV-visible spectra, and fourier transform infrared (FTIR) spectra. The composting temperature was steady in the thermophilic range for 24 and 12 d in the intensive and maturation phases, respectively, which fulfilled the disinfection requirement. Moreover, the temperature increased rapidly to 76.8℃ within three days, and the thermophilic temperatures peaked twice and lasted longer than in traditional composting, which accelerated SS degradation and decreased the composting period necessary to obtain mature compost. FTIR spectroscopic analysis showed a diminished in methyl group derived from methylene C-H aliphatic groups because of organic matter degradation by microorganisms and an increased number of aromatic chains. The new technology may be a viable and sustainable alternative for SS management that converts waste into compost that is useful as a soil amendment.