• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.370-373
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• 2000

In this work, an extractive membrane bioreactor containing coulture broth of Burkholderia cepacia G4 PR1 constitutively expressing the TCE-degrading enzyme, tolune-ortho-monooxygenase(TOM), was used for the degradation of TCE. The membrane bioreactor operates by seperating the TCE-containing waste gas from the aerated biomedium, by which the air-stripping of TCE without degradation was overcome that could occur in conventional aerobic biological treatments of TCE-contaminated waste gases. This was achieved by a silicone rubber membrane which was coiled around a perspex draft tube. TCE from the gas phase diffuses across the silicone rubber membrane into microbial culture broth that was continuously fed from a separate aerobic CSTR. Therefore, TCE degradation occured without the TCE being directly exposed to the aerating gas stream. Of the TCE supplied to the membrane bioreactor, 72.6% was biodegraded during the operation of this system. To construct a mathematical model for this system, parameters describing microbial growth kinetics on TCE were determined using a CSTR bioreactor. Else parameters used for numerical simulation were determined from either indepedent experiments or values reported in the literature. The model was compared with the experimental data, and there was a good agreement between the predicted and the measured TCE concentrations in the system. To achieve a higher treatment efficiency, various operating conditions were simulated as well.

• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.37-46
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• 2004

The analysis of enzymes associated with metabolism of phenolics by Stenotrophomonas maltophilia LK-24 was conducted. To identify metabolites of phenol and phenol compound, we investigated enzymes of S. maltophilia LK-24 associated with degradation of phenolics. We found that phenol hydrolase, catechol-2.3-dioxygenase, 2-hydroxymuconic semialdehyde dehydrogenase, 2-hydroxymuconic semialdehyde hydroxylase and acetaldehyde dehydrogenase were activated. The results showed that phenolics were gone through the meta-pathway ring cleavage. The results will contribute greatly to understand metabolic pathways of phenol and it is possible to make some assessment of the feasibility of using S. maltophilia LK-24 for the treatments of phenolic-contaminated waste streams.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.11a
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• pp.266-270
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• 2008

The construction wastes have been enormously increased after 90's, but construction wastes have depended on reclamation, therefore the environmental disruption and contamination are getting in the hot issue of society and in controversy with residents. With the consequence that indicates a substitute about an application of construction waste units is the most important thing for studying construction wates of quantity when the construction units are demolished. Nowadays, the area under the housing environment amelioration policies is getting rapidly old, then it is beyond anticipating reconstruction. Likewise, it is common when the process of construction wastes make progress to investigate uneconomically in point of facts, therefore to derive economical effects using construction wastes units should be urgent as soon as possible. In conclusion, the purpose of this study offers the variety of construction wastes and process of treatments, comparison of which the construction is demolished and economical effects of application of construction units.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.3
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• pp.187-193
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• 2004

In this study, Anaerobic sewage sludge in a batch reactor operation at $35^\circ{C}$ was used as the seed to investigate the effect of pretreatments of waste activated sludge and to evaluate its hydrogen production potential by anaerobic fermentation. Various pretreatments including physical, chemical and biological means were conducted to utilize for substrate. As a result, SCODcr of alkali and mechanical treatment was 15 and 12 times enhanced, compared with a supernatant of activated sludge. And SCODcr was 2 time increase after re-treatment with biological hydrolysis. Those were shown that sequential hybridized treatment of sludge by chemical & biological methods to conform hydrogen production potential in bath experiments. When buffer solution was added to the activated sludge, hydrogen production potential increased as compare with no addition. Combination of alkali and mechanical treatment was higher in hydrogen production potential than other treatments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.6
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• pp.588-591
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• 2004

There is an increasing interest in the use of electrochemical methods for the animal waste treatment The technologies using the electrochemical method provide ideal tools for approaching industrial and animal wastes problems. Unlike other chemical treatments, the electrochemical systems do not make the volume of the secondary waste increase. The electrochemical methods can be operated with electrochemical apparatus and inorganic agent allow selective separation and recovery and even quieter than others. This study concerns design factors, electrode construction and wastewater treatment process of the electrochemical apparatus. The experiment of color, COD and BOD removal is much effective in using electrochemical method with ultrasonication and ozonation.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.627-634
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• 2016

The objectives of this study were to select optimal soil amendments through analysis of heavy metal availability in soil and uptake to Aster koraiensis Nakai for forest rehabilitation of heavy metal contaminated soil of abandoned metal mine. A. koraiensis was cultivated for 6 months at contaminated soil with several soil treatments (bottom ash 1 and 2%, fly ash 1 and 2%, waste lime+oyster 1 and 2%, Acid mine drainage sludge (AMDS) 10 and 20%, compost 3.4%, non-contaminated natural forest soil, and control). The analysis results of heavy metal concentrations in the soil by Mehlich-3 mehthod, growth and heavy metal concentrations of A. koraiensis showed that waste oyster+lime 1% and compost were more effective than the other amendments for phytostabilization. However, it is needed comprehensive review of factors such as on-site condition, slope covering to reduce soil erosion and vegetation introduction from surround forest for revegetation to apply forest rehabilitation.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.3
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• pp.173-179
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• 2010

In a HLW repository, the buffer is exposed to an elevated temperature due to a radioactive decay and geochemical conditions for a long time and such a hydrothermal condition may cause a significant loss of its barrier function. This study carried out hydrothermal tests with a domestic smectite clay to investigate the changes in the expandibility, layer charge, and cation exchange capacity of the smectite. When the temperature and potassium concentration in solution was increased for the hydrothermal treatments, the expandibility decreased, the layer charge negatively increased, and the CEC also decreased.

• Microbiology and Biotechnology Letters
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• v.3 no.3
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• pp.135-140
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• 1975

For the purpose of producing single cell protein out of an agricultural waste, chestnut-bur was hydrolyzed with 4％ H$_2$SO$_4$, solution for 30 min under the steam pressure of 1.5kg/$\textrm{cm}^2$, and 21％ saccharification of the original carbon source was obtained. When Candida tropicalis was grown in the hydrolyzate the cell yield remained only 21％ of the original sugar suggesting a necessity of further treatments.

• Journal of Korea Society of Waste Management
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• v.34 no.5
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• pp.474-481
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• 2017

This study was conducted to investigate the effects of inoculum and carbon sources on anaerobic digestion characteristics. The treatments were combinations of inoculum (digestate of cattle manure and rumen fluid) with carbon sources (starch, cellulose, and xylan). Anaerobic digestion was performed in triplicate at $37^{\circ}C$ for 18 days at 100 rpm. Sampling was performed at 0, 1, 2, 3, 4, 5, 7, 9, 12, 15, and 18 days to measure pH, ammonia-N, volatile solids reduction, the cumulative methane content, and the cumulative methane production. There was a significant difference in methane content depending on the carbon source and there was a significant difference in pH, ammonia-N, methane production, and methane content depending on the inoculum (P < 0.05). The results of methane production were higher in the digestate of cattle manure treatment than in the rumen fluid treatment (P < 0.05). In this study, different digestive patterns depending on the type of carbon source could be used as basic research data to set the hydraulic residence time of anaerobic digestion facilities. In addition, the use of ruminal fluid as an inoculum may help accelerate the hydrolysis and acid production steps.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.4
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• pp.427-438
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• 2023

Thermodynamic sorption modeling can enhance confidence in assessing and demonstrating the radionuclide sorption phenomena onto various mineral adsorbents. In this work, Ca-montmorillonite was successfully purified from Bentonil-WRK bentonite by performing the sequential physical and chemical treatments, and its geochemical properties were characterized using X-ray diffraction, Brunauer-Emmett-Teller analysis, cesium-saturation method, and controlled continuous acid-base titration. Further, batch experiments were conducted to evaluate the adsorption properties of Cs(I) and Sr(II) onto the homoionic Ca-montmorillonite under ambient conditions, and the diffuse double layer model-based inverse analysis of sorption data was performed to establish the relevant surface reaction models and obtain corresponding thermodynamic constants. Two types of surface reactions were identified as responsible for the sorption of Cs(I) and Sr(II) onto Ca-montmorillonite: cation exchange at interlayer site and complexation with edge silanol functionality. The thermodynamic sorption modeling provides acceptable representations of the experimental data, and the species distributions calculated using the resulting reaction constants accounts for the predominance of cation exchange mechanism of Cs(I) and Sr(II) under the ambient aqueous conditions. The surface complexation of cationic fission products with silanol group slightly facilitates their sorption at pH > 8.