• 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.

• 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.

• Preventive Nutrition and Food Science
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• 제6권2호
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• pp.112-116
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• 2001

Oxidized potato starch/polyethylene (PE) cast films were prepared with different percentages of linear low density PE (LLDPE), oxidized potato starch and prooxidant. For the determination of biodegradability of the films, lignocellulose-degrading Streptomyces viridosporus T7A (ATCC 39115) was used. Films were chemically disinfected and incubated with S. viridosporus by shaking at 100 rpm at 37$^{\circ}C$ for eight weeks. Hydroxyl indices of the films by Fourier-Transform Infrared Spectroscopy, mechanical Properties of the films by Instron and film morphology by scanning electron microscope (SEM) were measured. The hydroxyl index of the film containing the oxidized potato starch incubated with S. viridosporus T7A was higher than that of the corresponding control. All the films containing 5% and 10% oxidized starch showed a decrease of tensile strength on the films after incubation when the corresponding uninoculated film was compared. In the oxidized starch/PE film incubated with S. viridosporus T7A, partial destruction of starch and PE was examined by SEM.

• 대한화학회지
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• 제57권3호
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• pp.377-381
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• 2013

Thevetia peruviana (Yellow Oleander) seed oil was extracted with n-hexane in a soxhlet extractor. The ethanolysis and methanolysis of the oil were carried out with 50% of potassium hydroxide in ethanol and methanol respectively by weight of oil, as catalyst. The biodiesel was tested for biodegradability using E. coli. The percentage yield of the FAEE and FAME were 84.8% and 91.6% respectively. The biodegradability values of 81.4% and 86.2% were obtained for FAEE and FAME respectively after a period of 28 days. Other fuel quality parameters determined are the cetane index of 47.19 (FAEE) and 58.97 (FAME), flash point of $198^{\circ}C$ (FAEE) and $175^{\circ}C$ (FAME), kinematic viscosity at $40^{\circ}C$ of 5.21 $mm^2s^{-1}$ (FAEE) and 5.10 $mm^2s^{-1}$(FAME), pour point of $4^{\circ}C$ (FAEE) and $-2^{\circ}C$ (FAME) and a cloud point of $6^{\circ}C$ (FAEE) and $3^{\circ}C$ (FAME). Thus, Thevetia peruviana oil has a high potential for use in production of environmentally friendly biodiesel.

• Preventive Nutrition and Food Science
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• 제3권1호
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• pp.27-35
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• 1998

Starch-polyethylene films containing high molecular weight(NW) oxidized-polyethylene and prooxidant were prepared , and thermal -and bio-degradability of the films were determined. Increased levels of starch resulted in a corresponding reduction in mechanical strength of the films. However, the addition of high MW oxidized-polyethylene did not significantly reduce the percent elongation of the films. Thefilms containing high MW oxidized-polyethylene andproosicant were degreaded faster than those containing no aadditive during the heat treatment. The films lost their measureable mechanical properties when their weight-average MW(Mw) fell below 50,000. Biodegradability of the films was determined by a pure culture assay with either Streptomyces badius 252.S. setonii 75Vi2 or S. viridosporous T7A, and by an extracellulr enzyme assay using S. setonii 75vi2. The results from pure culture assay indicated that biomass accumulation on the film surface inhibited chemical and biological degradation of the films. The extracellular enzyme assay demonstrated decrease of percent elongation and increase of carbonyl index of the films. Therefore, extracellular enzyme assay could be used as a good method to evaluate biodegradability of the films.

• 공업화학
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• 제32권3호
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• pp.260-267
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• 2021

본 연구에서는 코코넛 오일로부터 카르복실레이트계 음이온 계면활성제 SLEC-3을 합성하였으며, 합성된 계면활성제의 구조를 FT-IR, ¹H-NMR 및 ¹³C-NMR 분석을 통하여 확인하였다. 합성한 계면활성제 SLEC-3에 대하여 임계 마이셀 농도, 정적 및 동적 표면장력, 유화력, 거품 안정성 등의 계면 물성을 측정한 결과, 기존 세제 제품에서 널리 사용되는 음이온 계면활성제 SLES와 비교하여 계면 활성이 보다 우수하고 계면 에너지를 낮추는데 더 효과적이었다. 또한 SLCE-3에 대한 생분해성, 급성 경구 독성 및 급성 피부자극 시험을 실시한 결과, 저자극 및 저독성을 가지고 있기 때문에 세제 및 세정제 제품에 적용할 수 있을 것으로 판단되었다.

• 한국환경농학회지
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• 제42권4호
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• pp.427-434
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• 2023

본 연구에서는 볏짚과 토마토와 같은 농업부산물이 우분의 혐기성 소화를 통한 메탄 생성에 미치는 영향을 알아보기 위해 각 기질을 단독 소화한 것과 혼합 소화한 것을 비교하였다. 우분의 경우 토마토와 병합 소화했을 때 우분 단독 소화 시보다 메탄 생성량이 증가하였고, 혼합 기질 내 토마토 함량이 중요한 역할을 하였다. 본 연구를 통해 농업부산물을 활용한 분뇨의 바이오가스화 향상 가능성을 확인하였다.

• 상하수도학회지
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• 제37권5호
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• pp.253-259
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• 2023

Bioreactors are devices used by sewage treatment plants to process sewage and which produce active sludge, and sediments separated by solid-liquid are treated in anaerobic digestion tanks. In anaerobic digestion tanks, the volume of active sludge deposits is reduced and biogas is produced. After dehydrating the digestive sludge generated after anaerobic digestion, anaerobic digested wastewater, which features a high concentration of organic matters, is generated. In this study, the decomposition of organic carbon and nitrogen was studied by advanced oxidation process. Ozone-microbubble flotation process was used for oxidation pretreatment. During ozonation, the TOC decreased by 11.6%. After ozone treatment, the TOC decreased and the removal rate reached 80.4% as a result of the Ultra Violet-Advanced Oxidation Process (UV-AOP). The results with regard to organic substances before and after treatment differed depending on the organic carbon index, such as CODMn, CODCr, and TOC. Those indexes did not change significantly in ozone treatment, but decreased significantly after the UV-AOP process as the linkage treatment, and were removed by up to 39.1%, 15.2%, and 80.4%, respectively. It was confirmed that biodegradability was improved according to the ratio of CODMn to TOC. As for the nitrogen component, the ammonia nitrogen component showed a level of 3.2×10² mg/L or more, and the content was maintained at 80% even after treatment. Since most of the contaminants are removed from the treated water and its transparency is high, this water can be utilized as a resource that contains high concentrations of nitrogen.

• 한국지반환경공학회 논문집
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• 제15권7호
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• pp.39-50
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• 2014

본 연구에서는 도시개발 시 저영향개발(Low Impact Development, LID) 기법을 적용하였을 때, 토양 지하수 환경과 생태경관에 미치는 영향을 총체적으로 평가하는 방법의 framework 구축을 목적으로 문헌조사 연구를 수행하였다. 그 결과 토양 지하수 환경생태 건강성은 (i) 수리지질학적 지하수 오염 취약성, (ii) 생화학적 오염도와 (iii) 토양의 오염 정화능력의 여러 요소들에 의해서 측정되어 종합 및 평가되는 것이라는 개념을 설정하였고, 이들 각각의 요소에 미치는 영향 평가를 위한 측정 항목 선정과 각 요소의 측정치를 종합화해서 등급화 및 지표화하는 방법을 제시하였다. 또한 토양 지하수 환경 건강성과 기존의 환경 영향 평가에서 고려하는 생태 및 경관 요소를 GIS(Geographic Information System)와 AHP(Analytic Hierachy Process) 기반을 활용 및 접목하여 토양 지하수뿐만 아니라 생태 경관 등 LID의 자연환경에 미치는 영향을 총체적으로 평가하는 측정 항목 및 지표 산정과 그에 따른 활용 방법을 제시하였다. LID 기술의 계획 및 설계 단계에서 활용할 수 있는 최적화를 위해서 LCIA(Life Cycle Impact Assessment) 방법상의 framework로 활용하는 것을 본 연구에서는 제안하였다.