• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.164-167
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• 2001

현장에서 채취한 토양을 이용하여 Microcosm test를 실시한 결과 온도 및 수분함량이 높을수록 BTEX 분해율이 증가하는 것으로 나타났으며 산소 농도는 21~32% 정도가 적당하였다. 그러나 BTEX 초기농도가 높은 경우에는 생분해율이 감소하는 것으로 나타났다. Bioventing 공법을 현장에 적용한 결과 OUR(Oxygen Utilization Rate)값은 6.3~16.3%O$_2$/day로 조사되었으며 Biodegradation rate 값은 3.4~8.8 mg hydrocarbon/kg soil/day로 조사되어 생물학적 처리 가능성이 있는 것으로 평가되었다.

• Journal of the Korean Wood Science and Technology
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• v.38 no.6
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• pp.568-578
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• 2010

In this study, the possibility of biodegradation of polychlorinated biphenyls (PCBs) by various white rot fungi was evaluated, and outstanding white rot fungi for the degradation of PCBs were selected. Seven white rot fungi were used to degrade Aroclor 1254 and 1260, which are widely considered to be toxic and difficult to degrade. And the degradation rates of Aroclors by selected white rot fungi were performed by GC analysis. Through the resistance test of white rot fungi on different concentrations of PCBs, the inhibition of mycelial growth of Cystidodontia isubellina was much less than that of others, and this fungus grew faster than others, relatively. Based on this result, it was considered that C. isubellina was selected as degrading fungus for Aroclors. As a result of biodegradation rate of Aroclors by Cystidodontia isubellina, the degradation rate of Arolor 1254 was reached to 57.57% in 13 days, which showed very high degradation rate. Also the degradation rate of Aroclor 1260 by C. isubellina had a tendency of increasing along with increasing incubation day. Maximal degradation rate of Aroclor 1260 was 49.43% at 13 days. Based on this results, it indicated that in comparison with a previous study, high degradation rate was obtained by C. isubellina.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6B
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• pp.689-694
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• 2006

The system performance of a bioactive foam reactor (BFR), that consists of a foam column using a surfactant and a biodegradation basin containing suspended bacteria, was investigated for the treatment of gaseous toluene or a mixture of four volatile organic compounds (VOCs, benzene, toluene, p-xylene, and styrene). Overall, the BFR achieved stable VOC removal efficiencies, indicating that it can be used as a potential alternative over conventional packed-bed biofilters. Furthermore, a dynamic loading test showed that relatively constant removal was maintained at the elevated loading due to a high mass transfer rate in the foam column. However, as the inlet concentration of VOCs increased, a portion of the VOCs mass-transferred to the liquid phase was stripped out from the biodegradation basin, resulting in a decrease in the overall removal efficiency. In the BFR, the removal efficiency of the individual VOC was mainly determined depending on the biodegradation rate (styrene > toluene > benzene > p-xylene), rather than the mass transfer rate. Consequently, increases in the microbial activity and the volume of the basin could improve the overall performance of the BFR system. Further investigation on microbial activity and community dynamics is required for the BFR when subjected to high loadings of VOC mixtures.

• Korean Journal of Microbiology
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• v.44 no.1
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• pp.22-28
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• 2008

Cutting oils are emulsionable fluids widely used in metal working processes. Their composition is mineral oil, water, and additives (fatty acids, surfactants, biocides, etc.) generating a toxic waste after a long use. Cutting oils also affect colour, taste and odour of water, making it undesirable for domestic and industrial uses. In these days, conventional treatment methods as evaporation, membrane separation or chemical separation have major disadvantages since they generate a concentrated stream that is more harmful than the original waste. In this study, our purpose is to reduce cutting oils by using biological treatment. Eighty one strains were isolated from cutting waste oil of industrial waste water sludge under aerobic conditions. Among these strains, KS47, which removed 90.4% cutting oil in 48 hr, was obtained by screening test under aerobic conditions(pH 7, $28^{\circ}C$). KS47 was identified as Pseudomonas aeruginosa according to morphological, physiological and biochemical properties, 16S rDNA sequence, and fatty acid analysis. P. aeruginosa KS47 could utilize cutting oil as carbon source. In batch test, we obtained optimal degradation conditions(1.5 g/L cell concentration, pH 7, and temperature $30^{\circ}C$). Under the optimal conditions, 1,060 mg/L cutting oil was removed 83.7% (74.1 mg/L/hr).

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.2
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• pp.112-117
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• 2016

This research compared the tensile performance of the vegetation mat, which was developed byu using the rapidly growing biodegradable plastic, Poly Lactic Acid(PLA), according to the biodegradation period. The test applied the method defined by Korean Standard KS. In the result of experiment using single-material PLA mesh and PLA plastic, the tensile strength and molecular weight were inverse-proportional to the 5 months of biodegradation period. The thickness of PLA mesh was increased by 11.2~13.4% while the tensile strenth of it was reduced by 32.4~55.4%. The tensile strength and molecular weight of PLA plastic were also reduced over time. However, the tension test of vegetation mat comprised of PLA mesh, non-woven fabric (including seeds), and jute net didn't have specific tendency.

• Journal of Environmental Health Sciences
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• v.42 no.2
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• pp.112-117
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• 2016

Objectives: In this study, we investigated the biodegradation rates of 8 perfluorooctanesulfonate (PFOS) alternatives synthesized at the at Changwon National University in comparison to those of PFOS potassium salt and PFOS sodium salt. Methods: A biodegradability test was performed for 28 days with microorganisms cultured in the good laboratory practice laboratory at the Korea Environment Corporation following the OECD Guidelines for the testing of chemicals, Test No. 301 C Results: While $C_5H_8F_3SO_3K$, $C_8F_{17}SO_3K$ and $C_8F_{17}SO_3Na$ were not degraded after 28 days, the 3 alternatives were biodegraded at the rates of 31.4% for $C_8H_8F_9SO_3K$, 25.6% for $C_{10}H_8F_{13}SO_3K$, 23.6% for $C_{25}F_{17}H_{32}S_3O_{13}Na_3$, 20.9% for $C_{15}F_9H_{21}S_2O_8Na_2$, 15.5% for $C_{23}F_{18}H_{28}S_2O_8Na_2$, 8.5% for $C_{17}F_9H_{25}S_2O_8Na_2$ and 4.8% for $C_6H_8F_5SO_3K$. When the concentration was the same(500 mg/L), $C_{23}F_{18}H_{28}S_2O_8Na_2$ had the lowest tension with 20.94 mN/m, which was followed by $C_{15}F_9H_{21}S_2O_8Na_2$ (23.36 mN/m), $C_{17}F_9H_{25}S_2O_8Na_2$ (27.31 mN/m), $C_{25}F_{17}H_{32}S_3O_{13}Na_3$ (28.17 mN/m), $C_{10}H_8F_{13}SO_3K$ (29.77 mN/m) and $C_8H_8F_9SO_3K$ (33.89 mN/m). Having higher surface tension of 57.64 mN/m and 67.57 mN/m, respectively, than those of the two types of PFOS salts, $C_6H_8F_5SO_3K$ and $C_5H_8F_3SO_3K$ were found valueless as substitute for PFOS. Conclusion: The biodegradation test suggest that 6 compounds could be used as substitutes for PFOS. $C_{23}F_{18}H_{28}S_2O_8Na_2$ and $C_{15}F_9H_{21}S_2O_8Na_2$ were found to be the best substitutes based on biodegradation rate and surface tension, followed by $C_{25}F_{17}H_{32}S_3O_{13}Na_3$, $C_8H_8F_9SO_3K$ and $C_{10}H_8F_{13}SO_3K$. $C_{17}F_9H_{25}S_2O_8Na_2$ was found to have relatively low value as an alternative but it still had a potential to substitute the conventional PFOS.

• Korean Journal of Environmental Agriculture
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• v.21 no.4
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• pp.261-268
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• 2002

Biodegradation of monochlorophenols by wood rot fungi such as Daldina concentrica, Trametes versicolor and Pleurotus ostreatus was evaluated by determining their resistance or toxic test and biodegradability. The metabolites of monochlorophenols were also analyzed. Among the three fungi, T. versicolor was the most resistant to 200 ppm of 2-, 3- and 4-chlorophenols, and did not show any inhibitory mycellium growth. But D. concentrica had a little inhibition effect at more than 100 ppm of 3- or 4-chlorophenol. Control cultures of P. ostreatus took even 14 days far the completion of mycellium growth, but the hyphal growth was improved when 2- or 3-chlorophenol were added to the culture. In biodegradation analysis, P. ostreatus showed the highest degradation of 2- or 3-chlorophenol, while T. versicolor was the most effective in 4-chlorophenol. D. concentrica and P. ostreatus slowly degraded 4-chlorophenol. However, T. versicolor had similar degradation capability in the three monochlorophenols, suggesting that the biode- gradation nude is dependent on the fungi as well as the type of monochlorophenol. Several metabolites such as 1,3,5-trihydroxyl benzene, 1-ethyl-1-hydroxyl pentane, 2-propenoicacid, methylmalonic acid and 2-methyl-4-keto-pentan-2-ol were found as products of primary oxidation of 2-, 3- and 4-chlorophenols by intact fungal cultures. fatty acids including tetradecanoic, heptadecanoic and octadecanoic acids were also detected The order of increase of mycellium weight during incubation were P. ostreatus > T. versicolor > D. concentrica. The pH in the culture was not constantly changed depending on incubation days, but the mycellium weight was slightly increased, indicating that the biodegradation of monochlorophenol might have low relationship with the mycellium growth Laccase activities of T. versicolor and P. ostreatus were continuously increased depending on the incubation days, suggesting that the ligninolytic enzyme activity play an important role in the biodegradation of monochlorophenol.

• Journal of Soil and Groundwater Environment
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• v.21 no.2
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• pp.22-28
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• 2016

In order to evaluate landfill stabilization based on organic carbon, stoichiometric analysis and a biological methane potential (BMP) test based on modeling were performed at the 2^nd Sudokwon Landfill Site. Mass balance analysis through a BMP test proved to be more adaptable for evaluation, and it showed that 28.9% of landfill organic carbon was expected to remain by 2046, 30 years after landfill closure. The organic carbon ratio of total landfill waste for 2046 is forecasted as 2.9% in demolition waste and 5.1% in household waste, and, if one were to consider plastic as an organic waste, the ratios would increase to 15.9% and 28.3%, respectively. Therefore, it seems that organic matter biodegradation facilitating measures such as bioreactor landfill technology and preemptive recovery of combustible waste are necessary to shorten post closure management periods and to meet the landfill stabilization guidelines more safely.

• Korean Journal of Environmental Biology
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• v.17 no.2
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• pp.147-152
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• 1999

The efficiency of the OECD MITI(I) test which is designated as a standard method for measuring the biodegradability of chemicals by the Korean Ministry of Environment was evaluated and compared with those of two other OECD ready biodegradability tests： the manometric respirometry test and the closed bottle test. All the tests were applicable to a wide variety of organic chemicals and there were no significant differences in biodegradation rates of eight test chemicals and a reference chemical with three methods. However, the MITI(I) test had unnecessary expense and complexity in preparation of a mixed inoculum. Decrease in bacterial diversity during pre-conditioning of the inoculum for 1 month was observed and therefore the mixed inoculum did not ensure the presence of a variety of species in the test. Based on the simplicity, cost-effectiveness and reproducibility of the test procedure, it is considered that the manometric respirometry test is the most adequate method which can replace the MITI(I) test method.

• Journal of the Korean Society of Tobacco Science
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• v.36 no.1
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• pp.1-11
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• 2014

Cigarette filters containing Brassica Rapa L. seeds of the dark brown and round shaped were evaluated to determine the effect of seed addition on filter degradability. The seeds with germination capability under the tar/nicotine condition in the preliminary test, were put into the active carbon part of the filter(12mm) during filter rod making by the kit. The $4{\pm}2$ pieces of the seeds were put into the opened fiber bundle of the filter tow. In order to test the germination rate of the seeds, seed filters were placed either in a petri dish or test-pot in a conditioned area ($25^{\circ}C$, 70 % RH). The seed filters were placed outdoors exposed to natural conditions with the periodic water supply. The seeds in the smoked filters showed 90 % germination rate after a month under the open air condition. No significant differences in the sensory evaluation and analysis were obtained when the control sample was compared to the same cigarettes with the seeds.