• 한국환경보건학회지
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• 제23권2호
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• pp.35-43
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• 1997

A study on the effect of the biodegradability of the composting bulking agent in the swine manurecomposting was carried out in a batch system. The purpose of this study is to prove the effect of the biodegradability of the composting-bulking agent on the efficiency of the composting. In this study, it is the lignins: Klason-Lignin in the volatile solid that the index of the biodegradability of the composting-material mixes which are pig manure-rice straw pig manure-sawdusts pig manuremixture of rice and ricestraw (2:1) pig manure-mixture of rice and sawdust (1:1). It was carried out in the same condition (moisture contents, air supply rate, C/N ratio, initial input weight, porosity-structure) except the biodegradability of the raw material mixes. One of the results from this study is that the biodegradability of the bulking agent in the sense of the VS lignin content is not an insignificant factor in composting reaction. The less contents of the lignin in VS, the more efficiencies of the cornposting reaction in use of these parameters for the degree of the reaction: temperature, the trends of the ash contents, the change pattern of the C/N ratio. Under some assumptions, it is able to induce rough model on the relation of the VS lignin contents with the efficiency of the degradability. In this model, the biodegradability of the bulking agent is not an insignificant factor however, it is flexible within some degrees of range.

• 한국물환경학회지
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• 제21권1호
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• pp.1-6
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• 2005

The effect of ozone oxidation on biodegradability of leachate was studied. Ozone oxidation process was used as pre-treatment process to enhance performance of biological process in treating landfill leachate. Optimum ozone dosing rate and contact time in this experiment was $160mg\;O_3/L$ hr and 45 minutes, respectively. Biodegradability was enhanced 5.08% by ozone oxidation. The ratio of ozone demand/DOC concentration was $0.049{\sim}0.091mg\;O_3/mg$ DOC. The increase of biodegradability depending on ozone dosing rate(D) and contact time(T) can be expressed as follows ; ${\Delta}E=0.00479{\cdot}D^{0.773}{\cdot}T^{0.800}$ The biodegradation rate of DOC was increased proportionally with the increase of ozone dosing rate and contact time irrespective of landfill site age. The increase of biodegradability by ozone addition was not satisfactory. It is hard to expect significant increase in biodegradability by ozone treatment only. Thus, it is evaluated that ozone oxidation can not increase biodegradability significantly in concentrated wastewater composed of complex organic compound such as leachate.

• 한국의류학회지
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• 제25권7호
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• pp.1270-1280
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• 2001

In this research of biodegradable polymers, it is essential to investigate the relation between biodegradability and molecular structure such as chemical constitution, hydrophilicity, molecular weight, crystallinity, chain orientation, and so on. It is also expected that hydrophilicity of polymer can affect biodegradability because biodegradation occurs with the help of enzymes and microorganisms. This study is to investigate the effect of hydrophilicity on biodegradability of polyesters. Hydrophilicity was varied by adding 5~30 mol% of amide groups, since amide groups are hydrophilic and used for improving thermal and mechanical properties. Surface energies and nitrogen contents by ESCA were measured to determine their hydrophilicity. The biodegradation was examined in activated sludge, enzyme and natural soil by $CO_2$evolution, TOC, weight loss, and observation through microscopy. The results showed that hydrophilicity of polyesteramide films increased with the addition of amide, PBAD series of shorter methylene units showed maximum hydrophilicity at 15~20 mol% of amide contents, but PBSE exhibited maximum values at 5~15 mol% of amide contents. The biodegradability increased as the hydrophilicty on surface increased. The biodegradation rate of PBAD series was higher than that of PBSE series. Therefore, it can be concluded that the addition of appropriate contents of hydrophile enhanced the biodegradability of aliphatic polyesters as well as their physical properties. Also, the experimental results revealed the relation between hydrophilicity and biodegradability of polyesteramides.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.139-144
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• 2003

1, 4-dioxane is a recalcitrant pollutant found in contaminated ground waters and industrial effluents. Conventional water treatment techniques are limited to treat this compound effectively. In this study, $O_3$／$H_2O_2$ oxidation process was used to eliminate 1, 4-dioxane in water and to enhance the biodegradability. Several factors affecting biodegradability enhancement were investigated. The relationship between initial oxidation rate of 1 A-dioxane and BOD enhancement rate has been determined, a kinetic model has been proposed. $H_2O_2$ concentration and pH had a proportional relation with biodegradability of 1, 4-dioxane, but in case of ozone, there was no relationship with biodegradability. 1, 4-Dioxane removal efficiencies had good agreement with the biodegradability.

• Archives of Pharmacal Research
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• 제16권4호
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• pp.312-317
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• 1993

To confirm a new evaluation tedhnique for biodegradability of biopolymer microsphers in vivo condition, magnetic microsphere sytem was adopted for tracing the microspheres injected and lodged in micr. Microsphers of poly(DL-lactic acid), poly(L-alctic acid) and poly(DL-lactide-coglycolide)(PLGA) were prepared by solvent-extraction method and their organ distribution and biodegradation in mice was examined. Magnetic microspheres lodged in mice organs were recollected from the homogenates of mice organs with a constant flow magnetic separation apparatus. Recollected microspheres were observed by scanning electron microscopy and also were assayed for their magnetite ocntent by atomic absorption spectrophotometry to evaluate the biodegradability of polymeric microspheres. This method seems to be practical and simple to estimate the biodegradability of biopolymers over the conventional methods.

• 한국의류학회지
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• 제30권4호
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• pp.607-614
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• 2006

This study was carried out to suggest the optimal spinning process condition which provides a proper range of tenacity and biodegradability as textile fibers. The effects of the melt spinning speed and heat treatment on the mechanical property and biodegradability of polylactic acid fiber were investigated. Polylactic acid(PLA) was spun in a high spinning speed of $2000{\sim}4000m/min$. Each specimen was heat-treated at $100^{\circ}C$ during 30min. Mechanical properties such as breaking stress and the degree of crystallinity were evaluated using WAXS. Biodegradability was estimated from the decrease of breaking stress, weight loss, and the degree of crystallinity after soil burial. Experimental results revealed that heat treated specimens showed higher breaking stress than untreated specimens, but the increase was not so high as was expected from the remarkable change of crystallinity by heat treatment. It was concluded that breaking stress was more influenced by spinning speed than heat treatment. In the soil burial test, however biodegradability calculated from weight loss was more influenced by heat treatment than spinning speed.

• 상하수도학회지
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• 제24권5호
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• pp.603-608
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• 2010

More than 8 millions of chemical have been used for human activities and lots of chemicals can not be degraded by microbial activities in this world. To show the biodegradability of a chemical, biodegradability index (B.I.) is suggested using aerobic biodegradability by $BOD_5$/COD, anaerobic biodegradability by methane potential (M.P.) and toxicity by the luminiscent bacteria. In this study, PVA (polyvinyl alcohol), HEC (hydroxy ethyl cellulose), 2,4,6-TCP (tri-chloro phenol) and 2,4-DCP (di-chloro phenol) are used for test chemicals. Though they show little toxicity, PAV and HEC have low B.I. because they are polymers having high molecular weight. That means that there are no bacteria that has enzyme to degrade polymer molecules. Also, anaerobic treatment is suggested better than aerobic treatment from B.I. 2,4,6-TCP and 2,4-DCP show high toxicity and have low B.I. Their low biodegradabilities seem to be originated from their toxicities. If B.I. is used in wastewater treatment, better treatment process can be suggested and finally it can lead our society to make more environment-friendly chemicals.

• KSBB Journal
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• 제19권2호
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• pp.132-137
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• 2004

생산된 바이오디젤 (지방산 메틸에스테르)을 기반으로 한 여러가지 합성윤활유 베이스를 분석대상으로 하여 생분해도를 분석평가하였다. 또한 기존 석유디젤과 바이오디젤의 생분해성을 함께 비교 검토하였다. 호기적인 조건하에 생분해성 윤활유의 수상에서는 생분해성을 이산화탄소 발생량을 기준으로 생분해성을 조사하는 OECD 301 B에 근거하여 윤활유를 분석한 결과 펜타에리스리톨계 윤활유 베이스들의 28일째의 최종 생분해도는 61.1∼80.3%로서 모두 생분해도가 있음을 알 수 있었으며, 바이오디젤은 생분해도가 가장 높았다(83.5%). 분석의 상대오차, 독성대조군, 분석절차대조군과 관련된 규정에 의해 석유디젤을 제외하고 모두 타당한 절차에 의해 분석되었음을 입증할 수 있었다.

• 한국의류학회지
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• 제28권8호
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• pp.1048-1056
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• 2004

Hydrophilicities of finished cotton fabrics were evaluated in respect of moisture regain and wickability. Changes in internal structure were determined using X-ray diffraction and surface changes in degraded samples were observed through a microscopy. Activated sludge test, soil burial test and enzyme hydrolysis were employed to evaluate the biodegradabilities. In addition, correlation analysis was done between biodegradability and the factors affecting biodegradability in each evalution methods. It was shown that hydrophilicities of silicone finished specimens were lower than that of untreated cotton and decreased in a row of PDMS(polydimethyl siloxane : -CH$_3$)＞AFS(amino functional siloxane ; -C$_3$H$_{6}$ NHC$_2$H$_4$NH$_2$)＞MHPS(methylhydrogen polysiloxane : -H, Cat : (C$_{17}$ H$_{35}$ COO)$_2$Zn) Although, moisture regain of mercerized cotton was higher than those of the others, wickability was shown to be lower. It was represented that crystalinities of cotton fabrics decreased by the silicone treatment. In activated sludge test and soil burial test, biodegradabilities of silicone treated specimens were lower than that of untreated cotton, where specimens of higher biodegradability exhibited higher biodegradability except mercerized ones. The results from enzyme hydrolysis, however, showed somewhat different tendency in that biodegradability was more closely related with the crystallinities of fabrics. It can be thought that enzyme hydrolysis is carried out for short time, physical accessibility becomes important.

• 한국토양비료학회지
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• 제46권4호
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• pp.296-302
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• 2013

This study was carried out to investigate the effect of organic content level on ultimate methane potential and anaerobic biodegradability of substrate by biochemical methane potential assay. Three organic matters (whole sludge and liquid and solid fraction of sludge) of the same origin, which had different organic contents, were fermented at the batch anaerobic reactor for 70 days. Ultimate methane potential and anaerobic biodegradability were determined by the terms of volatile solid (VS) and chemical oxygen demand (COD). Volatile solid contents of whole sludge and solid and liquid fraction of sludge were 2.4, 18.8, and 0.2% and COD were 5.3, 30.4, and 0.5%, respectively. Ultimate methane potentials ($B_u$-COD) and anaerobic biodegradability ($D_{VS}$) determined by VS content were $0.5Nm^3kg^{-1}-VS_{added}$, 76.3% for whole sludge, $0.5Nm^3kg^{-1}-VS_{added}$, 76.3% for the liquid fraction of sludge, and $0.6Nm^3kg^{-1}-VS_{added}$, 77.0% for the solid fraction of sludge. Ultimate methane potentials ($B_u$-COD) and anaerobic biodegradability ($D_{COD}$) determined by COD were $0.2Nm^3kg^{-1}-COD_{added}$, 73.4% for whole sludge, $0.2Nm^3kg^{-1}-VS_{added}$, 74.0% for the liquid fraction of sludge, and $0.33Nm^3kg^{-1}-COD_{added}$, 99.1% for the solid fraction of sludge. In conclusion, ultimate methane potential and anaerobic biodegradability given by the VS term showed more reasonable results because COD might be underestimated by the interference of $NH_4{^+}$ in the case of highly concentrated organic material.