• Journal of Environmental Science International
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• v.7 no.1
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• pp.96-103
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• 1998

To study the optimum conditions of composting with industrial wastewater sludge, the variations of temperature and $CO_2$ generation amount during the composting periods were investigated. The conditions were that industrial wastewater added to bulking agents such as sawdust and rice hull was used, and differently treated with microorganism seeding or not, initial C/N ratios, air flow rate and initial moisture contents, respectively. The results were summarized as follows : Seeding 5% of microorganism was higher the temperature than not seeding. And using sawdust as bulking agents, and adjusting 30~40 of Initial C/N ratio, 200ml/l.min. of k flow rate and 67~68% moisture contents were higher the temperature than any other conditions. Seeding 5% of microorganisms was higher $CO_2$ generation amount than not seeding. And that was much in the order of 7~40, 30~34 and 22~23 of initial C/N ratio. Judging from the results, it should be considered that the optimum conditions in the composting of industrial wastewater sludge were seeding of 5% microorganisms, and adjusting 30~34 of Initial C/N ratio, 200ml/l min. of air flow rate and 67~68% of Intitial moisture contents. The contents of inorganic matters and C/N ratio during the composting periods at optimum condition were a little Increased. and heavy metals contents after composting were lower than standard for fortllizer.

• 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.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.16-21
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• 1998

To study the possibility of agricultural utilization of sewage sludge, the changes of the substances physico-chemical and microbiological properties composting periods such as inorganic matter, the form of organic matter and nitrogen and the kinds and the population number of microorganisms were investigated. The results were summarized as follows ; Temperature and $CO_2$ generation, they were the highest in the second day of composting periods and then were gradually fallen. pH value was not changed in first day during composting periods, but in second day was rapidly increased and then it was constant of the range of 8.4∼8.6. The contents of $P_2O,\;K_2O$, CaO and Fe were a little increased during composting periods, while that of ${SO_4}^{2-}$and Mn were big increased with 253${\sim}$331% and 191${\sim}$208% in late composting periods in comparing with early composting periods, respectively. The contents of ether extracted materials, water soluble polysaccharides, hemicellulose and cellulose were decreased but that of resins and lignin were not changed during composting periods. The contents of total and organic nitrogen during composting periods were decreased with 15${\sim}$20% and 22${\sim}$35%, respectively, while that of inorganic nitrogen was decreased with 75${\sim}$116%. The population numbers of microorganism during composting periods was much too changed according to the kinds of microorganism and composting periods.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.382-389
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• 1997

To study the optimum conditions of composing with sewage sludge, the variations of temperature and $CO_2$ generation amount during composting periods were investigated. The conditions were that sewage sludge added to bulking agents such as sawdust and rice hull were used and differently treated with microorganism seeding or not, initial C/N ratio, air flow rate and initial moisture contents. The results were summarized as follows : Seeding of 5% microorganism was higher temperature than not seeding. And using rice hull as bulking agents, and adjusting 21${\sim}$22 of initial C/N ratio, $200ml/l\;{\cdot}\;min$. of air flow rate and 64${\sim}$65% of initial moisture contents were higher temperature than any other conditions. Seeding of 5% microorganism was more $CO_2$ generation amount than not seeding. And using saw dust was more $CO_2$ generation amount than using rice hull as bulking agents. In the case of initial C/N ratio, adjusting 21${\sim}$42 was also more $CO_2$ generation amount than adjusting 12${\sim}$14. Judging from the result, it should be considered that the optimum conditions of composting with sewage sludges were seeding of 5% microorganism and adjusting 21${\sim}$22 of initial C/N ratio, $200ml/l\;{\cdot}\;min$. of air flow rate and 64${\sim}$65% of initial moisture contents.

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.2
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• pp.17-28
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• 1997

To study the possibility of agricultural utilization of industrial wastewater sludge, the changes of the substances, such as temperature, pH, inorganic and organic matter, the form of nitrogen, fatty acid and the population number of microorganisms during composting periods were investigated. Temperature and $CO_2$ generation were the highest in the second day of composting peroids, and then were gradually fallen. And they were similar to room temperature after the sixth day of composting periods. C/N ratio was a little increased as time went by. pH value was not changed in early composting periods and then pH had been gradually decreased since it was rapidly increased. It was in the range of 8.7~8.8 in late composting periods. The contents of $P_2O_5$, $K_2O$, CaO, MgO and Fe were a little increased and that of ${SO_4}^{2-}$ was increased with 62~67% in late in comparing with early composting periods. The contents of ether extracted materials, water soluble polysaccharides, hemicellulose and cellulose were decreased but that of resins and lignin were not changed during composting periods. The contents of total and organic nitrogen were decreased but that of inorganic nitrogen was increased during composting periods. The population number of microorganism during composting periods was too much changed according to the kinds of bulking agents and microorganisms, and the composting periods.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.406-412
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• 2008

Biogas plant with anaerobic digestion is receiving high attention as a facility for both livestock waste treatment and electric power generation. Objective of this study was to perform life cycle assessment (LCA) of a biogas plant which incorporates swine and food waste (7:3) as source materials for biogas production. In addition, the biogas production process was compared with the prevalent composting method as a reference in the aspects of green house gas (GHG) reduction potential and environmental impact. The biogas method was capable of reducing 52 kg $CO_2$ eq. emission per ton of swine/food waste, but the composting process was estimated to emit 268 kg $CO_2$ eq. into air. The biogas method was evaluated as more beneficial to the environment by mitigating the impact on abiotic depletion potential (ADP), global warming potential (GWP), ozone depletion potential (ODP), eutrophication potential (EP), and photochemical ozone creation potential (POCP), but not to acidification potential (AP).

• Journal of Animal Environmental Science
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• v.18 no.3
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• pp.145-150
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• 2012

This study was conducted to measure methane ($CH_4$) and nitrous oxide ($N_2O$) emissions from the 6 month old litter stockpile used for korean native cattle (Hanwoo) from August 3, 2007 to October 4, 2007. Daily mean $CH_4$ emissions was peaked to 273.013 ${\mu}g\;m^{-2}\;s^{-1}$ (SE : ${\pm}1.047{\mu}g\;m^{-2}\;s^{-1}$) on first day and then gradually decreased to 2.309 ${\mu}g\;m^{-2}\;s^{-1}$ (SE : ${\pm}0.061{\mu}g\;m^{-2}\;s^{-1}$) at the end of this experiment. Daily mean $N_2O$ emissions was as little as 0.269 ${\mu}g\;m^{-2}\;s^{-1}$ (SE : ${\pm}0.018{\mu}g\;m^{-2}\;s^{-1}$) on first day, but exponentially increased up to 3.569 ${\mu}g\;m^{-2}\;s^{-1}$ (SE : ${\pm}0.454{\mu}g\;m^{-2}\;s^{-1}$) on 43rd day and then slowly decreased to 1.888 ${\mu}g\;m^{-2}\;s^{-1}$ (SE : ${\pm}0.012{\mu}g\;m^{-2}\;s^{-1}$) at the end of this experiment. Carbon dioxide equivalent ($CO_2$-eq), calculated by global warming potentials of $CH_4$ or $N_2O$, of $CH_4$ on first day occupied approximately 99% of sum of $CO_2$-eq of $CH_4$ and $N_2O$. Methane emissions decreased and $N_2O$ emissions increased so that $CO_2$-eq ratio of $CH_4$ to $N_2O$ was 50:50 on 34th day. The effect of $N_2O$ on the ratio was increase thereafter. The ratio of daily mean $CH_4$ and $N_2O$ emissions to daily error of the mean was calculated to find daily fluctuation of $CH_4$ and $N_2O$ emissions. The ratio of $CH_4$ was less than 1.0% till 11th day but increased to 10.9% on 57th day. The ratio of $N_2O$ (0.4%~51.0%) was higher than that of $CH_4$, showing high in early stage and then gradually decrease, which was different from the pattern of $CH_4$. The ratio of daily mean emissions to daily error of the mean was little in case of active $CH_4$ or $N_2O$ generation period, which would be caused by the temporal and spatial heterogeneity of composting process. Hence more air supply on early stage to decrease $CH_4$ generation and proper turning to reduce spatial heterogeneity are needed to mitigate greenhouse gas emissions.