• Polymer(Korea)
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• v.26 no.1
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• pp.145-151
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• 2002

Thermoplastic starch(TPS) was prepared from mixing starch and glycerol by twin extruder. The blends were then prepared from high density polyethylene(HDPE) and TPS. Mechanical properties, thermal properties, and morphology of the blends were investigated. Their biodegradability was also studied by using aerobic composting method(ISO14855). Tensile strength, modulus and elongation at break decreased as the content of TPS increased. In particular elongation at break decreased rapidly even at the lower content of TPS. The melting temperatures of the blends were not changed, which showed that HDPE and TPS were immiscible. The morphology of the fractured surface of blend films was investigated by scanning electron microscopy(SEM). It was found that phases were separated. After composting for 45days, the biodegradability of the blends increased as the content of TPS increased.

• Journal of Animal Environmental Science
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• v.7 no.2
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• pp.111-118
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• 2001

This study was performed for measuring the emission of greenhouse gases, $CH_4,\;N_2O$, from the composting process for pig slurry. For the experiment the benchscale pilot plant was designed by 1$m^3$ volume reactor with a closed type and operated; sawdust 142kg filled before input slurry, slurry about 10~20l inputed per day (total 380l), air supplied 5l/min for 24 hours, mixing time 10 min./day and 1 time a day. From the total experiment period(30days), the amount of VS degradation and emission $CH_4$, $N_2O$ were 10.9kg-VS and 1,582.4g-$CH_4$, 68.1g-$N_2O$ respectively. Based on VS inputed the emission of $CH_4$, $N_2O$ were 15.3(g-$CH_4$/kg-V $S_{input}$), 0.7(g-$N_2O$ /kg-V $S_{input}$), and based on VS degradated were 145.2(g-$CH_4$/kg-V $S_{removed}$), 6.2(g-$N_2O$ /kg-V $S_{removed}$).

• Journal of Korea Society of Waste Management
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• v.34 no.2
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• pp.140-147
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• 2017

This study was conducted to evaluate the effects of physical characteristics. Twelve specific odorous compounds and various sources of bacteria were tested via treatment of food waste using an ultra-thermophilic aerobic composting process. Food waste was mixed with seed material and operated for 47 days. During composting, the temperature was maintained at $80-90^{\circ}C$. The variations in $O_2$, $CO_2$ and $NH_3$ production suggested typical microorganism-driven organic decomposition patterns. After composting, the concentrations of 12 specific odorous compounds other than ammonia did not exceed the allowable exhaust limits for odor. After composting, thermophiles represented 50% of all bacteria. After composting, the percentage of thermophile bacterial increased by 15%. Therefore, both stable composting operation and economic benefit can be expected when an ultra-thermophilic composting process is applied to food waste.

• KOREAN POULTRY JOURNAL
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• v.37 no.10 s.432
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• pp.85-89
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• 2005

우리나라 양계산업은 그동안 외형적으로 사육규모의 확대를 통해 소규모 내적으로도 사육시설의 현대화를 통하여 생산성의 향상과 양계산물의 고급화를 추구해왔다. 그러나 한편으로는 국민의 환경의식의 향상과 함께 환경문제가 크게 대두되면서 환경오염방지에 대한 요구도 더욱 커지고 있으며 가축사육의 규모화 및 단지화는 지역집중화를 초래하고 계분 이용의 불균형을 심화시키는 한 원인이 되고 있다. 또한 닭 사육밀도가 지역에 따라 이미 적정선을 웃돌아 계분의 관리 잘못으로 토양오염, 대기오염, 수질오염 등의 역기능을 유발하고 있다. 생계분 조차도 돈을 받고 판매하던 시절은 이제 옛이야이가 되었고 공을 들여 잘 제조한 양질의 퇴비 조차도 판매처가 없어서 창고에 쌓아놓고 판매처를 찾아야 하는 어려움을 겪고 있는 실정이다. 그러나 1962년부터 시작된 화학비료에 대한 보조금을 2005.7.1부터 폐지되었으며 동시에 화학비료의 보조금을 유기질비료에 확대지원하고 있어서 앞으로 유기질비료의 이용은 더욱 증가할 것으로 예상된다.

• Korean Journal of Agricultural Science
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• v.34 no.2
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• pp.181-188
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• 2007

This study was conducted to estimate the humificating grade according to experiment of physico-chemical characterization and phyto-toxicity during composting of using with pig manure and castor meal. The material ratios of the compost which was mixed with pig manure(P), castor meal(C), and saw dust(S) were 5 : 1 : 4(PCS-I), 5 : 2.5 : 2.5(PCS-II) and 5 : 4 : 1(PCS-III) by volume to volume, and they were decomposed for 60 days. In the result, the changes of temperature in all treatments during composting were rapidly increased more than $68^{\circ}C$ at the incipient stage, and gradually decreased within $39^{\circ}C$ at 60 days the after treatment. pH was slowly increased from 7.5 to 7.7, and the C/N ratio was 13~14 at the final composting stage. The low C/N ratio value in this compost was caused by the castor meal contented high nitrogen level(T-N 5.7 %). G.I.(germination index) was showed 73 to 78 range in all treatments at the $60^{th}$ day. Among all treatments PCS-I was appeared to be the best condition for composting.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.2
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• pp.87-95
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• 1996

A questionary survey was performed to invetigate the citizen's attitude concerning the waste incineration facility. People disliked most cremetorim followed by waste transfer station, chmical factory, waste incineration facility and sanitary landfill. Most people favored 1km minimum distance of incineration facilities from the residence. Most people think that we need most composting facilities in the future followed by sanitary landfill and incineration facilities. Majority of people was willing to accept the perfect incineration facilities near their residence. However, 37.6% answered no. Most people accepted complusory measures by the goverment in the location of incineration facilites. One incineration facility per one city or Gun was slightly favored than multy-city or Gun incineration facility. People think that perfect thchnology most important to overcome Nimby's.

• Korean Journal of Environmental Biology
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• v.25 no.3
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• pp.260-266
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• 2007

A thermophilic bacterium capable of poly (L-lactide)(PLLA) degradation was isolated from cultivating soil in Korea. The isolate was Gram positive rod-shaped bacterium, and was identified as Geobacillus caldoxylosilyticus based on the 16S rDNA sequence analysis. The strain proved to be a new PLLA degrading bacterium which has not been reported in the open literatures yet. The degradation activity of the strain was assessed in a sterilized compost inoculated with the strain under controlled compost condition at $58^{\circ}C$ for 40 days. The strain mineralized 66%, 57%, 41% and 40% of PLLA5000, PLLA11000, PLLA34000 and PLLA256000 whose weight average molecular weights were 5000, 11000, 34000 and 256000, respectively. Incorporation of 0.1% each of gelatin, yeast extract and ammonium sulfate in the compost containing PLLA256000 as a nutritional supplement raised the biodegradation activity by 27%, 13% and 10%, respectively. Increase of the inoculum size from $10^9cfu\;g^{-1}\;to\;10^{10}cfu\;g^{-1}\;and\;10^{11}cfu\;g^{-1}$ also enhanced the biodegradation activity by 14% and 20%, respectively.

• Korean Journal of Agricultural Science
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• v.35 no.1
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• pp.25-32
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• 2008

This study was conducted to find an optimal combination rate of castor meal for the good qualitative compost and to estimate the humification grade by physico-chemical characterization and phyto-toxicity test during composting of the mixture with cow manure and castor meal. The material ratios of the compost which was mixed with cow manure(C), castor meal(C), and saw dust(S) were 5 : 1 : 4(CCS-1), 5 : 2.5 : 2.5(CCS-2) and 5 : 4 : 1(CCS-3) by volume to volume, and they were decomposed for 60 days. In the result, the changes of temperature in all treatments during composting radically increased more than $63.6^{\circ}C$ at the incipient stage, and gradually decreased around $42^{\circ}C$. At the 60 days after the treatment, pH was slowly increased from 7.0 to 8.0, and the C/N ratio was 12.3~13.8 at the final composting stage. The low C/N ratio value was caused by the castor meal with high nitrogen level(T-N 5.7%). G.I.(germination index) showed in the range of 77.5 to 82.6 in all treatments. Among all treatments CCS-1 was appeared to be the best condition for composting. Therefore, the combination rate of castor meal which was used for compost humification improvement could be recommended 10% to manufacture the good qualitative cow manure compost.

• Clean Technology
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• v.13 no.2
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• pp.87-98
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• 2007

As the interest in environmental problems increased, the guideline of effluent qualities becomes strict and the amount of sludge produced from the wastewater treatment facilities steeply increased. The revised Korean acts prohibit the direct reclamation of the sludge exhausted in sewage treatment works from 2003, and the ocean dump of sludge will be also prohibited from 2012. Therefore, the sludge must be recycled, incinerated or composted. To properly perform the utilization and disposal operations, the establishment of well-defined procedures for the characterization of sludge by physical, chemical and biological method and setting up of guidelines for different treatment and disposal routes has become necessary. However, there have not been such standardized methods for sludge characterization in Korea. This review analyzes the present status of establishment and problems of sludge characterization method of Korea. Finally, it was proposed total 15 items of standardized characterization methods suitable to our country for proper sludge recycling and disposal, which was based on the more systematic standard methods of Germany (DIN 38414) and those of advanced nations.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.377-384
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• 2012

This study was carried out to evaluate effect of temperature condition on nitrogen mineralization of organic matter, distribution of microbial group by PLFA profiles, and soil microbial community in non-volcanic ash soil. Dried soil 30 g mixed well each 2 g of pellet (OFPE) organic fertilizers, pig manure compost (PMC), and food waste compost (FWC). And then had incubated at $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$, respectively. Nitrogen mineralization rate increased with increasing temperature and that was in the order of FWC>OFPE>PMC. Distribution ratio of microbial group by PLFA profiles showed that was different significantly according to incubation temperature and the type of organic matter. As incubating time passed, density of microbial group decreased gradually. The Gram-bacteria PLFA/Gram+ bacteria PLFA, Fungi PLFA/Bacteria PLFA, and Unsaturated PLFA/saturated PLFA ratios were decreased according to the increasing temperature gradually. Principal component analysis using PLFA profiles showed that microbial community structures were composed differently by temperature factor at both 75 days ($10^{\circ}C$) and 270 days ($30^{\circ}C$). In conclusion, Soil microbial community structure showed relative sensitivity and seasonal changes as affected by temperature and organic matter type.