• Title, Summary, Keyword: Bubble Column

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Effect of Nano-Bubble on Removal of Complex Heavy Metals (나노버블이 복합중금속(구리/납) 오염물 제거에 미치는 영향 분석)

  • Lee, Yang-Gyu;Han, Jung-Geun;Choi, Ju-Hyun;Kim, Dong-Chan;You, Seung-Kyong;Hong, Kikwon
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.4
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    • pp.139-146
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    • 2015
  • This paper describes a effect of nano-bubble on removal of complex heavy metals, in order to remove pollutants of soil with copper (Cu) and lead (Pb) based on column test. It was conducted column test considering inflow and fine soil contents condition, and then it was analyzed removal effect of nano-bubble on Cu and Cu/Pb. The test result showed that the removal effect of the nano-bubble was higher than that of distilled water regardless of fine soil contents in case of Cu pollutant, and the removal effect of nano-bubble on heavy metals was found to have a significant impact on Pb than Cu in case of Cu/Pb pollutants. It was also analyzed that engineering properties (like a flow path and permeability) of soil due to void ratio has influenced a significant impact the pollutants removal of nano-bubble. The test results determined that nano-bubble can be applied as a flushing agent for priority target pollutant in complex heavy metals.

Holdup Characteristics of Three Functional Regions in a Slurry Bubble Column (삼상 슬러리 기포탑의 세 기능영역 체류량 특성)

  • Jang, Ji Hwa;Lim, Dae Ho;Kang, Yong;Jun, Ki Won
    • Korean Chemical Engineering Research
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    • v.48 no.3
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    • pp.359-364
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    • 2010
  • Three kinds of functional regions such as continuous slurry(${\varepsilon}_f$), bubble(${\varepsilon}_b$) and wake(${\varepsilon}_w$) regions were identified, and the individual phase holdups of each functional region were determined in a three-phase slurry bubble column of 0.152 m ID. The holdups of bubble and wake were measured by adopting the electrical resistivity probe method. Effects of gas velocity and solid concentration in the slurry phase on the individual holdups of functional regions in the column were discussed. The holdup of continuous slurry phase decreased but that of bubble or wake increased, with an increase in the gas velocity in the column. The increase of solid content in the slurry phase could lead to the increase in the holdup of continuous slurry phase but decrease in the bubble or wake holdup. The portion of wake holdup was in the range of 15~40% of the bubble holdup, which decreased with increasing gas velocity or solid content in the slurry phase. The individual holdups of three functional regions were well correlated with operating variables within this experimental conditions.

Production of Itaconic Acid at Various Bioreactors (다양한 생물반응기에서 이타콘산의 생산)

  • 박승원;김승옥;이진석
    • Microbiology and Biotechnology Letters
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    • v.22 no.3
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    • pp.304-308
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    • 1994
  • A suitable culture method and bioreactor type for itaconic acid production were chosen by comparing the maximal concentration of itaconic acid produced in various systems. In batch culture, the maximal concentration of itaconic acid produced in a bubble column reactor was about 5% greater than that produced in stirred-tank or external-loop airlift reactor. These results were thought to be due to lower shear force and higher mass transfer efficiency in a bubble column reactor in comparison with other reactors. Moreover, the fed-batch mode in a bubble column was found to be a suitable one, producing about 25% higher concentration of itaconic acid compared to batch mode.

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Biodegradation of Toluene using Biofilms in a Bubble Column Bioreactor

  • Choi, Yong-Bok;Lee, Jang-Young;Kim, Hak-Sung
    • Journal of Microbiology and Biotechnology
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    • v.5 no.1
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    • pp.41-47
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    • 1995
  • Biodegradation of toluene in liquid effluent stream was carried out using biofilms of Pseudomonas putida formed on celite particles in the bubble column bioreactor. Silicon rubber tubing was installed at the bottom of the bioreactor and liquid toluene was circulated within the tubing. Toluene diffused out of the tube wall and was transferred into the culture broth where degradation by biofilms occurred. The operating variables affecting the formation of biofihns on celite particles were investigated in the bubble column bioreactor, and it was found that formation of bifilm is favored by high dilution rate and supply rate of carbon source which stimulate the growth of initially attached cells. Continuous biodegradation of toluene using biofilms was stablely conducted in the bioreactor for more than one month without any significant fluctuation, showing a removal efficiency higher than 95% at the toluene transfer rate of 1.2 g/L/h.

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Inhanced Oxygen Supply of Xanthan Fermentations Using either Hydrogen Peroxide or Fluidized Particles in Tower Bioreators (탑형 생물반응기에서 과산화수소 또는 유동화 입자를 이용만 Xanthan 발효의 산소공급 향상)

  • 서일순
    • KSBB Journal
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    • v.17 no.2
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    • pp.142-147
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    • 2002
  • The decomposition of hydrogen peroxide was used for supplementing the oxygen during batch xanthan fermentations in a bubble column bioreactor in order to escape the oxygen transfer limitation that occurred at the high viscosity of culture broths. The xanthan production, however, was inhibited reversibly by dosing hydrogen peroxide. On the other hand, fluidized particles of glass beads with 8 mm diameter led to high gas-liquid oxygen transfer rates in three-phase fluidized beds, which resulted in higher space-time yields of the xanthan production compared to in the bubble column bioreactors.

Effects of Elicitors on Scopolamine Production of Scopolia parviflora Nakai Adventitious Roots in Bubble Column Bioreactor

  • Jung, Hee-Young;Kim, Won-Jung;Kang, Seung-Mi;Park, Dong-Jin;Kang, Young-Min;Choi, Myung-Suk
    • Korean Journal of Medicinal Crop Science
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    • v.12 no.5
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    • pp.378-383
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    • 2004
  • Scopolamine and hyoscyamine are important anticholinergic compounds. To increase the productivity, we have selected various elicitors and developed culture system using a bubble column bioreactor (BCB). As the same manner of elicitation in flask cultures, the elicitors were introduced into BCB cultures and the productivity was investigated. Except the bacterial elicitor of Staphyllococcus aureus, the elicitors inhibited hyoscyamine production. In scopolamine production, the elicitors revealed different responses from the results obtained in flask cultures. The elicitors of KCl and Candida albicans less increased the production than flask cultures. However, methyl jasmonate and S. aureus showed stronger positive effects on tropane alkaloid production. In particular, S. aureus was the most effective elicitor on scopolamine production and the elicitor resulted in the highly increased production, approximately 10 times higher than the control culture.

Effects and Optimization of Gamma-Amino Butyric Acid (GABA) Production Process using Glutamate Decarboxylase (GAD) (Glutamate Decarboxylase (GAD)를 이용한 Gamma-Amino Butyric Acid (GABA) 생산 및 최적화)

  • Kim, Eui Jin;Lee, Jung-Heon
    • KSBB Journal
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    • v.29 no.6
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    • pp.426-431
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    • 2014
  • pH controlled batch reactor and bubble column reactors have been developed in this research. They were used to produce high concentration of GABA and to determine optimal pH for GABA production. Glutamate decarboxylase (GAD) was isolated from recombinant E. coli and used for GABA production from monosodium glutamate (MSG). pH control was inevitable because the pH increased with MSG consumption. GAD showed highest activity at acidic conditions at pH 5.5 but the optimal pH for GABA production was pH 6.0. When 1.5 mole of MSG was used as reactant, the 1.05 mole of GABA was produced after 10 hrs batch reaction. Using bubble column reactors, 80 % of MSG was converted to GABA for 6 hrs reaction and 1.2 mole of GABA was produced.

Effects of Column Diameter on the Holdups of Bubble, Wake and Continuous Liquid Phase in Bubble Columns with Viscous Liquid Medium (점성액체 기포탑에서 탑의 직경이 기포, wake 및 연속액상 체류량에 미치는 영향)

  • Lim, Dae Ho;Jang, Ji Hwa;Kang, Yong;Jun, Ki Won
    • Korean Chemical Engineering Research
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    • v.49 no.5
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    • pp.582-587
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    • 2011
  • Holdup characteristics of bubble, wake and continuous liquid phases were investigated in bubble columns with viscous liquid media. Effects of column diameter(0.051, 0.076, 0.102 and 0.152 m ID), gas velocity($U_G$=0.02~0.16 m/s) and liquid viscosity(${\mu}_L$=0.001~0.050 $Pa{\cdot}s$) of continuous liquid media on the holdups of bubble, wake and continuous liquid phases were discussed. The three phase such as bubble, wake and continuous liquid phases were classified successfully by adapting the dual electrical resistivity probe method. Compressed filtered air and water or aqueous solutions of CMC(Carboxy Methyl Cellulose) were used as a gas and a liquid phase, respectively. To detect the wake as well as bubble phases in the bubble column continuously, a data acquisition system(DT 2805 Lab Card) with personal computer was used. The analog signals obtained from the probe circuit were processed to produce the digital data, from which the wake phase was detected behind the multi-bubbles as well as single bubbles rising in the bubble columns. The holdup of bubble and wake phases decreased but that of continuous liquid media increased, with an increase in the column diameter or liquid viscosity. However, the holdup of bubble and wake phases increased but that of continuous media decreased with an increase in the gas velocity. The holdup ratio of wake to wake to bubble phase decreased with an increase in the column diameter or gas velocity, however, increased with an increase in the viscosity of con-tinuous liquid media. The holdups of bubble, wake and continuous liquid media could be correlated in terms of operating variables within this experimental conditions as: ${\varepsilon}_B=0.043D^{-0.18}U_G^{0.56}{\mu}_L^{-0.13}$, ${\varepsilon}_W=0.003D^{-0.85}U_G^{0.46}{\mu}_L^{-0.10}$, ${\varepsilon}_C=1.179D^{0.09}U_G^{-0.13}{\mu}_L^{0.04}$.

Utilization of CFD Simulation Model for a Bubble Column Photobioreactor (버블 칼럼 광생물반응기의 내부 유동분석을 위한 전산유체역학 시뮬레이션 모델의 이용)

  • Yoo, J.I.;Lee, I.B.;Hwang, H.S.;Hong, S.W.;Seo, I.H.;Bitog, J.P.;Kwon, K.S.;Kim, Y.H.
    • Journal of The Korean Society of Agricultural Engineers
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    • v.51 no.5
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    • pp.1-8
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    • 2009
  • Photobioreactor (PBR) that houses and cultivates microalgae providing a suitable environment for its growth, such as light, nutrients, CO2, heat, etc. is now getting more popular in the last decade. Among the many types of PBRs, the bubble column type is very attractive because of its simple construction and easy operation. However, despite the availability of these PBRs, only a few of them can be practically used for mass production. Many limitations still holdback their use especially during their scale-up. To enlarge the culture volume and productivity while supplying optimum environmental conditions, various PBR structures and process control are needed to be investigated. In this study, computational fluid dynamics (CFD) was economically used to design a bubble-column type PBR taking the place of field experiments. CFD is a promising technique which can simulate the growth and production of microalgae in the PBR. To study bubble column PBR with CFD, the most important factor is the possibility of realizing bubble. In this study, multi-phase models which are generally used to realize bubbles were compared by theoretical approaches and comparing in a 2D simulation. As a result, the VOF (volume of fluid) model was found to be the most effective model to realize the bubbles shape as well as the flow inside PBR which may be induced by bubble injection. Considering the accuracy and economical efficiency, 0.005 second time step size was chosen for 2.5 mm mesh size. These results will be used as criteria for scale-up in the PBR simulation.