• Title/Summary/Keyword: hollow-fiber membrane

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Liquid-liquid extraction process for gas separation from water in polymeric membrane: Mathematical modeling and simulation

  • Salimi, Nahid;Moradi, Sadegh;Fakhar, Afsaneh;Razavi, Seyed Mohammad Reza
    • Membrane and Water Treatment
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    • v.7 no.5
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    • pp.463-476
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    • 2016
  • In this study, application of polypropylene hollow fiber membrane contactors for $CO_2$ removal from water in liquid-liquid extraction (LLE) mode was simulated. For this purpose, a steady state 2D mathematical model was developed. In this model axial and radial diffusion was considered to $CO_2$ permeation through the hollow fibers. $CO_2$ laden water is fed at a constant flow rate into the lumen side, permeated through the pores of membrane and at the end of this process, $CO_2$ solution in the lumen side was extracted by means of aqueous diethanolamine (DEA) and chemical reaction. The simulation results were validated with the experimental data and it was found a good agreement between them, which confirmed the reliability of the proposed model. Both simulation and experimental results confirmed the reduction in the percentage of $CO_2$ removal by increment of feed flow rate.

Study of the ageing of hollow fibers in an industrial module for drinking water production

  • Wang, S.;Wyart, Y.;Perot, J.;Nauleau, F.;Moulin, P.
    • Membrane and Water Treatment
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    • v.4 no.1
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    • pp.53-67
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    • 2013
  • In this study, ageing characteristics of an industrial hollow-fiber membrane module were investigated after 50 months of drinking water production. For this purpose, the industrial module was opened to make 18 smaller modules with hollow-fibers taken from different parts of the industrial module. These modules were probed by the use of a magnetic nanoparticle (NP) challenge test based on magnetic susceptibility (K) measurement of permeate. No magnetic susceptibility was detected in permeate when the challenge test was performed on an intact membrane module, indicating the complete retention of nanoparticles by the membrane. The compromised membrane module can be successfully detected by means of magnetic susceptibility measurement in permeate. So, this study clearly demonstrates that ageing of ultrafiltration membranes can be monitored by measuring the magnetic susceptibility of permeate from an ultrafiltration membrane module. These results showed that the hollow fibers in the center zones of the bundle would age faster than those in the outer zones around the bundle. This result is in agreement with numerical simulation (Daurelle et al. 2011).

Clinical Comparison Between Inside Blood Flow Type and Outside Blood Flow Type in the Hollow Fiber Oxygenator (Hollow Fiber Oxygenator에서 Inside Blood Flow Type과 Outside Blood Flow Type의 임상적 비교)

  • 안재호
    • Journal of Chest Surgery
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    • v.25 no.5
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    • pp.451-457
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    • 1992
  • The hollow fiber oxygenator is the most advanced one for the cardiopulmoanry bypass. They have two different types of the hollow fiber systems according to the way how the blood go through the fibers. One is inside blood flow type and the other outside type. In order to find out which is better to prevent blood cell destruction, we selected 40 valve replacing patients and divided them into 2 groups prospectively. In group I [n=20], inside blood flow type[BCM-7a], CO2 excretion is more effective than group II, that is partly because of the relative large surface area of the BCM-7. In group II [n=20], outside blood flow type [MAXIMAa], they have better quality to preserve platelet count. We also studied about several other items such as SaO2, Hemoglobin and RBC, WBC, fibrinogen, LDH, plasma hemoglobin, haptoglobulin and so on. But we cannot find any differences between two groups with any statistical meanings [p<0.05]. We conclude that both of two oxygenators are excellent in the aspects of gas exchange and blood cell preservation.

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Nitrogen Removal using Autotrophic Microorganism in Membrane-Attached Biofilm Reactor (MABR) (Membrane-Attached Biofilm Reactor(MABR)에서의 독립영양 미생물을 이용한 질소 제거)

  • Shin, Jeong-Hoon;Sang, Byoung-In;Chung, Yun-Chul;Choung, Youn-Kyoo
    • Journal of Korean Society on Water Environment
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    • v.21 no.6
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    • pp.624-629
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    • 2005
  • The purpose of this study is to investigate the performance of nitrogen removal using autotrophic microorganism in the Membrane-Attached Biofilm Reactor (MABR). The treatment system consists of an aerobic MABR (R1) for nitrification and an anaerobic MABR (R2) for hydrogenotrophic denitrification. Oxygen and hydrogen were supplied through the lumen of hollow-fiber membranes as electron acceptor and donor, respectively. In phase Ι, simultaneous organic carbon removal and nitrification were carried out successfully in R1. In phase II, to develop the biofilm on the hollow-fiber membrane surface and to acclimate the microbial community to autotrophic condition, R1 and R2 were operated independently. The MABRs, R1 and R2 were connected in series continuously in phase III and operated at HRT of 8 hr or 4 hr with $NH_4{^+}-N$ concentration of influent, from 150 to 200 mgN/L. The total nitrogen removal efficiency reached the maximum value of 99% at the volumetric nitrogen loading rate of $1.20kgN/m^3{\cdot}d$ in the combined MABR system with R1 and R2. The results in this study demonstrated that the combined MABR system could operate effectively for the removal of nitrogen in wastewater not containing organic materials and can be used stably as a high rate nitrogen removal technology.