• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.51.2-51.2
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• 2011

A novel electrospun nanofiber membrane was fabricated using combined poly (vinylphosphonic acid) (PVPA) and polyvinyl alcohol (PVA) intended for bone tissue engineering applications. PVPA is a proton-conducting polymer used as primer for bone implants and dental cements to prevent corrosion and brush abrasion. The phosphonate groups of PVPA have the ability to crosslink and attach itself to the hydroxyapatite surface facilitating faster integration of the biomaterial to the bone matrix. PVA was combined with PVPA to provide hydrophilicity, biocompatibility and improve its spinnability. To improve its mechanical strength, PVPA/PVA and neat PVA mixtures were combined to produce a multilayer scaffold. The physical and chemical properties of the of the fabricated matrix was investigated by SEM and TEM morphological analyses, tensile strength test, XRD, FT-IR spectra, swelling behavior and biodegradation rates, porosity and contact angle measurements. Biocompatibility was also examined in vitro by cytotoxicity and cell proliferation studies with MTT assay and cell adhesion behavior by SEM and confocal microscopy.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.329-338
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• 2006

The research aims to provide the basic data for practical applications by correlating the bio-kinetic coefficients with the load of recalcitrant organic matter in box-mill wastewater. The activated sludge process was employed to a Wastewater disposal plant in an industrial setting, increase of consequently leading to the organic load. The parameter values derived by Monod-kinetic analysis were as follows:specific substrate removal rate $K_{max}=0.17day^{-1}$, half saturation constants $K_s=60.37mg/l$, decay coefficient $K_d=0.142day^{-1}$, microbial yield coefficient y = 0.388mg/mg, and max specific growth rate ${\mu}_{max}=0.006day^{-1}$. In view of biodegradability, the $TCOD_{Mn}/TBOD_5$ ratios of inflow and outflow were 1.07 and 1.41, and the $SCOD_{Mn}/SBOD_5$ ratios of inflow and outflow were 1.10 and 1.50, respectively. The higher $TCOD_{Mn}/TBOD_5$ ratio of outflow indicated that metabolites of a microorganism have accumulated in the cells.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.1
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• pp.27-33
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• 1994

With the rapid industrialization, an ever-increasing quantity and kind of new organic compounds pose environmental problems due to their toxicity and physiological effect. However, research on the biodegradation of these compounds under anaerobic condition is very limited inspite of its efficiency and economical advantage. In this research, the pH effect on the ring cleavage of phenol under anaerobic condition was investigated, and the theory of phase separation was applied to the degradation of phenol for investigating the role of acidogenic bacteria. Results, obtained from biochemical methane potential(BMP) assay for 15.5 days of incubation, showed that acidic condition was more desirable for phenol degradation than alkaline condition. By both unacclimated methanogenic granular sludge and two mixed cultures, phenol was completely removed within six weeks of incubation with a gas conversion rate of over 86% of theoretical one. However, phenol was not degraded by unacclimated acidogenic culture, and thus it is considered as a syntrophic substrate. In case of phase separated biochemical methane potential(PSBMP) assay, in which acidogenic and methanogenic culture were seeded separately and consecutively, those that had been subjected to normal acidogens for 3 to 4 weeks showed higher gas production than those seeded with sterile or frozen culture.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.521-529
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• 2007

Nutrient removal from synthetic wastewater was investigated using a MLE (Modified-Ludzack Ettinger) type MBBR (Moving Bed Biofilm Reactor), with different phenol ($C_6H_5OH$) concentrations, in order to determine the inhibition effects of phenol on biological nutrient removal and the biodegradation of phenolic wastewater. The wastewater was prepared by mixing a solution of molasses with known amounts of phenol and nutrients. The experiments were conducted in a lab-scale MLE type MBBR, operated with four different phenol concentrations (0, 67, 100 and 168mg/L) in the synthetic feed. Throughout the experiments, the ratio of the phenolic COD concentration to the total COD was varied from 0 to 1. Throughout batch test, the SNR (Specific Nitrification Rate) and SDNR (Specific Denitrification Rate) were significantly influenced by changes of the phenol concentration. Phenol was inhibitory to the nitrification/denitrification process, and showed greater inhibition with higher initial phenol concentrations. The SNR observed with 0, 67, 100 and 168mg phenol/L were very different like 10.12, 6.95, 1.51 and $0.35mg\;NH_{3^-}N/gMLVSS$ hr, respectively. Similarly, the SDNR observed at 0, 67, 100 and 168mg phenol/L were different like 0.322, 0.143, 0.049and 0.006mgN/gMLVSS day, respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.20-26
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• 2010

Paper composed mainly of organic materials and they can be used as nutrient by microorganisms. Therefore microorganisms are damaging the important documents and works of art irreversibly. Previous research reported that mycelium or spores of the fungi were observed on the wax of the volumes of King Sejong especially were heavily deteriorated by fungi. Fungal strains isolated from the annals of Joseon dynasty were identified as Biscogniauxia atropunctata, Aspergillus versicolor, Penicillium polonicum, Ceriporia lacerata, Irpex lacteus. Especially Aspergillus and Penicillium are able to grow on the substrates having a 7-8% moisture content, which is much lower than the general storage condition (RH55-60%) of the paper cultural properties. Moreover, they are known as fungi cause paper deterioration and discoloration. In this study, we selected Aspergillus versicolor and Penicillium polonicum among five strains, then biological aging has been executed for 30 days. The growth of Aspergillus versicolor and Penicillium polonicum in wax was lower than wax treated paper and Hanji. The growth of them in beeswax treated paper and Hanji both were excellent.

• Journal of Microbiology
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• v.39 no.3
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• pp.206-212
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• 2001

Catechol and 4-chlorobenzoate (4CBA) which are produced from the biodegradation of a variety of aromatic and chloroaromatics have been recognized as toxic to living organisms. In this study, the toxic effects of catechol and 4-chlorobenzoate on gram-positive and -negative bacteria were examined in terms of survival, morphology, change in fatty acids and membrane protein composition. The survival rate of the organisms during treatment for 6 h was decreased, as the concentration of each aromatic was increased. Escherichia coli and Pseudomonas cells treated with catechol and 4CBA at concentrations causing a significant decrease in their viability, showed destructive openings in their cell envelopes. Bacills subtilis treated with the aromatics were reduced in cell size and Staphylococcus aureus cells displayed irregular rod shapes with wrinkled surfaces. The bacterial cells treated with 20 mM catechol showed increases in unsaturated fatty acids, but several saturated fatty acids were decreased. In the E. coli cells treated with 20 mM catechol, inner membrane proteins of 150 kDa and 105 kDa were decreased. But several kinds of the inner and outer membrane proteins were increased. In B. subtilis treated with 20 mM catechol, several kinds of proteins were increased or decreased in membrane proteins.

• Journal of Microbiology
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• v.35 no.2
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• pp.141-148
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• 1997

Alcaligenes xylosoxydans strain SMN3 capable of utilizing biphenyl grew not only on phenol, and benzoate, but also on salicylate. Catabolisms of biphenyl and salicylate appear to be interrelated since benzoate is a common metabolic intermediate of these compounds. Enzyme levels in the excatechol 2. 3-dioxygenas which is meta-cleavage enzyme of catechol, but did not induce catechol 1, 2-dioxygenase. All the oxidative enzymes of biphenyl and 2, 3,-dihydroxybiphenyl (23DHBP) were induced when the cells were grown on biphenyl and salicylate, respectively. Biphenyl and salicylate could be a good inducer in the oxidation of biphenyl and 2, 3-dihydroxybiphenyl. The two enzymes for the degradation of biphenyl and salicylate were induced after growth on either biphenyl or salicylate, suggesting the presence of a common regulatory element. However, benzoate could not induce the enzymes responsible for the oxidation of these compounds. Biphenyl and salicylate were good inducers for indigo formation due to the activity of biphenyl dioxygenase. These results suggested that indole oxidation is a property of bacterial dioxygenase that form cis-dihydrodiols from aromatic hydrocarbon including biphenyl.

• 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.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.462-469
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• 2007

Isolation and application of oil-degradation microbes from the oil-contaminated soil and the determination of optimal operation conditions about the peat moss, the addition for the oil-biodegradation. After all experiments, we have acquired three important conclusions: First, we found out the 4 microbes, Pseudomonas fluorescens, Pseudomonas aeruinosa, Kurtia sp., Bacillus ceres, with excellent capability for the oil-degradation; Second, the optimal operating conditions of the peat moss for TPH treatment were pH $7{\sim}8$, temperature $25{\sim}30^{\circ}C$, water content 20%, mixing 2 times/ day, addition volume 2%; Third, in case of the application to the oil-contaminated soil with 4 mixed microbes, the removal efficiency of TPH was increased from 54% to 83% in oil-contaminated soil and from 65% to 85% in oil-contaminated soil with the peat moss.

• Journal of Environmental Science International
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• v.25 no.6
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• pp.757-766
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• 2016

MTBE and other gasoline additives contained in gasoline are known to be a refractory substance resistant to biodegradation. As a method of removing these substances, a research of method using native microbes of polluted soil was progressed and among these, bio-degradation possibility under aerobic condition was evaluated. All of the experiments were progressed based on batch experiment of lab scale and analyzed by GC-FID using HS-SPME technique. The result of bio-degradation experiment based on MTBE and other additives(ETBE, TAME) was observed below 1 mg/L, which initial concentration were 100 mg/L for each method. And through production of by-product and CO2, partial mineralization was confirmed. Degradation velocity of each additive was promptly represented in the order of TBA>ETBE>MTBE>TAME. Through this study, bio-degradation possibility of native microbes of oil polluted soil, MTBE and other gasoline additives was confirmed and it was considered that the result could be used for basic experiment data in removing oil pollutants of soil.