• Korean Journal of Environmental Agriculture
• /
• v.16 no.1
• /
• pp.44-47
• /
• 1997

The change in microbial flora has been studied through dwelling house composting by the composter with double layer walls. The results are summarized as followes. 1. Mesophilic bacteria increased and decreased mildly, thermophilic bacteria showed a tendency to decrease except for spring, and the number of mesophilic bacteria and thermophilic bacteria had a tendency to increase and decrease simultaneously. 2. The number of mesophilic actinomycetes were increased at the early stage of compositing in winter, mildly decreased in spring and slightly decreased in summer, and the number of thermophilic actinomycetes were decreased at the early stage of composting. 3. The decrease in the number of mesophilic fungi was observed at the middle stage in summer, but the mild increase was observed in spring and winter. The number of thermophilic fungi was generally decreased. 4. Ammonia oxidizer and nitrite oxidizer were observed in this field composting much more than in the other composting experiments.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.28 no.3
• /
• pp.99-106
• /
• 1986

This study was carried out to investigate the effects of moisture content, temperature, C/N ratio and pH of the sewage sludge mixed with hulle and sawdusts for making compost under aerobic condition and to improve the defect of the structure of experimental equipment heat lose and handling method. and obtained results were as follows 1.The temperature was reached 73$^{\circ}$ C around 50 hours fermentation in the condition of 0.8 L/min. of air and 60.4% of moisture content. and favorable moisture content of initial condition ranged from 50 to 65% 2.The temperature near bottom of the batch composter was decreased due to evaporate water vapor and lose the heat produced during aeration. and it is required to be improved. 3.The temperature in the batch composter from the center to the inside wall surface was gradually decreased. the temperatures of the points located in r=9cm and the wall surface were 4$^{\circ}$ C and 6$^{\circ}$ C respectively. and therefore it is required to be insulated. 4. The maximum C02 production was obtained as 7.3% per volume in the temperature of 63$^{\circ}$C at the moisture content of 60% 5.The temperature range of active microbes growth was found to be as 20$^{\circ}$C to 40$^{\circ}$C in the case of mesophiles and 50$^{\circ}$C to 65$^{\circ}$C in the case of thermophiles due to increase and decrease C02 production. 6.C/N ratio after decomposition was 1.3 to 2.6 smaller than that of initial one due to increase the amount of nitrogen. The more C/N ratio increased. the less the reaction velocity decresed. The optimum of it as found to be 30. 7.pH values after decomposition were slightly increased than that of initial ones. The reaction velocity was decreased at acid and alkall condition. Therefore it is neseseary to neutralize the medium to improve the reaction.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.12
• /
• pp.1874-1883
• /
• 2008

Bacterial diversity and the composition of individual communities during the composting process of swine and mushroom cultural wastes in a field-scale composter (Hazaka system) were examined using a PCR-based approach. The composting process was divided into six stages based on recorded temperature changes. Phylogenetic analysis of eighty 16S rRNA sequences from uncultured composting bacterial groups revealed the presence of representatives from three divisions, including plant pathogenic bacteria, high-molecule-degrading bacteria and spore-forming bacteria. The plant pathogen A. tumefaciens gradually decreased in abundance during the composting process and eventually disappeared during the thermophilic and cooling stage. A bacterium homologous to Bacillus humi first appeared at the early thermophilic stage and was established at the intermediate thermophilic, post-thermophilic, and cooling stages. It was not possible to isolate the B. humi during any of the stages using general culture techniques.

• 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 Environmental Agriculture
• /
• v.19 no.1
• /
• pp.51-57
• /
• 2000

Waste newspapers was used as an amendment to adjust the moisture of household food wastes for composting. The mixture of household food wastes and waste newspapers was composted in an especially designed small home composter, where the early fed composting materials were discharged early. The temperature inside composting materials was influenced very much by that of outside, because the composter was not insulated. Accordingly, the higher the outside temperature was, the higher the decomposition rate was. The temperature inside composting materials did not reach to optimum, because the amount of composting materials added in the composter everyday was too little, and it caused too high water content of discharged compost after 15 weeks. Therefore, it was required that the composter must be insulated to maintain the higher temperature. The inorganic compounds$(K_2O,\;CaO,\;MgO,\;P_2O_5)$ and heavy metals(Zn, Cu, Cr, Cd, Hg, As) were accumulated obviously in produced compost, when dry recycled compost was reused as the amendment for adjusting the moisture.

• Journal of Industrial Technology
• /
• v.24 no.B
• /
• pp.171-176
• /
• 2004

The effects of agitation and aeration for exopolysaccharide(EPS) production through batch cultivation of an Enterobacter sp. isolated from the composter were investigated. During the EPS fermentation under conditions of constant agitation speed from 200 to 900 rpm and constant aeration rate of 0.5-2.5 vvm, the low yields of EPS(4.8-5.2g/L) was observed as the viscosity increase of culture broth. With the stepwise increases in agitation speed and aeration rate, the EPS production and the viscosity of EPS were increased 1.3~1.4 times and 2.3~3.6 times higher than those of the fixed conditions, respectively. Therefore, these stepwise increases were considered as the key operating parameters for enhancing EPS production. The max. EPS(6.8g/L) and viscosity(14,000cp) were obtained when the agitation speed was increased from 300 to 900 rpm for 54hrs at 1.5 vvm.

• The Korean Journal of Mycology
• /
• v.27 no.1 s.88
• /
• pp.10-14
• /
• 1999

A single phase composter was constructed by modifying the conventional mixer of sawdust for the cultivation of oyster mushroom Pleurotus ostreatus. The machine was designed on the basis of 3-phase-1 system which was controlled in prewetting, pasteurization and fermentation processes. In composting 200 kg of straw and cotton waste in the machine, it took 20 minutes in prewetting step and also to hours at $65^{\circ}C$ in pasteurization process. Postfermentation by aerothermophiles was completed by treating the compost at $45^{\circ}C-50^{\circ}C$ for 48 hours which was shorten 24 hours from the conventional method. In the postfermentation at high temperature, forced aeration and/or vigorous mixing process(es) played a great role in the improvement of spawn quality. The growth of mycelium of oyster mushroom was excellent in the culture combinated with 3 parts of surface inoculation and 7 parts of mechanical mixing.

• Korean Journal of Environmental Agriculture
• /
• v.15 no.2
• /
• pp.179-187
• /
• 1996

This study was conducted to investigate the possibility of composting of household garbage. The composter with the double layer walls was operated for 60 days in each season. The following results were obtained at the end of the experiment, if the time was not specified. 1) The maximum temperature was $31^{\circ}C$ in spring, $36^{\circ}C$ in summer and $50^{\circ}C$ in winter. 2) The mass was reduced to an average of 58.5%. 3) pH values of the compost were 8.21 in spring, 8.29 in summer and 7.94 in winter. 4) The ash contents were 55.8% in spring, 57% in summer and 73.8% in winter. 5) The nitrogen contents were in the range of $0.2{\sim}5.8%$. Its values were the highest in winter and the lowest in summer. 6) Inorganic contents of the compost were in the range of : $P_2O_5$ ; $1.5{\sim}4.41%$, $K_2O$ ; $0.02{\sim}1.31%$, CaO $0.13{\sim}1.68%$ and MgO $0.05{\sim}1.22%$. 7) Heavy metal contents of the compost were in the range of : Zn ; $13{\sim}89mg/kg$, Cu ; $4{\sim}62mg/kg$, Cd ; $1{\sim}21mg/kg$, Pb ; $N.D.{\sim}97mg/kg$, Cr ; $N.D.{\sim}37$ and Hg ; $N.D.{\sim}1.38mg/kg$.

• Korean Journal of Soil Science and Fertilizer
• /
• v.31 no.1
• /
• pp.77-84
• /
• 1998

In order to investigate microbiological control of malodors, particularly including ammonia, the effect of three thermophilic ammonium tolerant bacteria strains. TAT112. TAT117 and TAT119, were tested during composting of pig manure in the laboratory scale composters. The total weight, volatile solids and BOD of the pig manure compost were decreased during composting process in all treatments. The temperature in all treatments rose in first 3 days dramatically, but that in control without inoculation reached its maximum most lately among the treatments. The nitrogen content of drain water accumulated inside and outside composter, and trapped in 6N $H_2SO_4$ was lower in TAT112 inoculated composter than in control. However, it was not lower in the treatment of TAT117 and TAT119 inoculated. Ammonia concentration in the exhaust gas monitored everyday during composting also demonstrated that it was lowest at TAT112 inoculated among all treatments. It was appeared to have an effect on reducing ammonia emission at the treatment of TAT112 inoculated than the control.

• Journal of Animal Environmental Science
• /
• v.12 no.1
• /
• pp.29-34
• /
• 2006

The effects of turning frequency were examined on the efficiency of composting lime treated excess sludge amended with sawdust from the activated sludge process after a liquid/solids separation process. The raw and excess sludge from the activated sludge process associated with the hog wastewater treatment system is a significant problem and composting is an effective method far reducing the pollution potential of hog wastewater sludge. The coagulant used sludge composting and ammonia emissions from composting are not well established. The effect of compost properties such as high total carbon, C/N ratio and pH value on performance of composting sludge and biofiltration of ammonia from composting process were investigated. The ammonia emission was not significantly increased during composting. The ammonia concentrations of the exhaust air of composter were ranged from 0.5 and 7 ppm about 12 days after composting. The performance of the hog wastewater sludge composting was the most sensitive to chemical treated sludge properties such as high total carbon and high C/N ratio of the initial compost mixes. Temperature in compost and ammonia emission were not greatly affected by the turning frequency.