Membrane oxygenation

Fundamental issues In spite of the advantages discussed in overview, gas transfer membranes have intrinsic problems that can be detrimental depending on application. Lumen condensation Lumen condensation occurs when the sweep gas supplied to the hollow fiber lumen immersed in liquid/water transfers to shell. This phenomenon commonly occurs in membrane oxygenation as shown in Fig. […]

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Water vapor condensation modeling for membrane oxygenation process

Assumptions Water vapor condensation phenomenon is fundamentally limiting the application of membranes for oxygenation as explainedhere. Modeling water vapor transfer through hollow fiber membrane can be considerably complicated. But, it can be performed fairly simply by assuming the following two. No gas transfer across the membrane except water vapor. No humidity gradient in the radial […]

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Effect of shear stress on biology

In immersed membrane process, high air flow rate increases flux by increasing shear rate on membrane surface that increases back transport of particles from the membrane surface as discussed here. However, excessive aeration can cause floc breakage that releases small particles confined in the floc. According to the critical flux theory, small particles are prone […]

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Why increasing flux is much more challenging than reducing membrane fouling?

Sustainable flux has hardly increased in last decades ¬†¬†¬†Membrane technology has been rapidly improved in recent decades. But, the improvements are mainly about lower fouling, lower energy consumption, easier installation and operation, more reliable membranes and modules, etc. rather than higher flux.¬† In RO membranes for surface water treatment, the typical design pressure of 15 […]

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Miscellaneous topics

¬†‚ÄĘ Sludge rheology ¬†‚ÄĘ Biosolids reduction by extending SRT ¬†‚ÄĘ Is forward osmosis (FO) a viable option? ¬†‚ÄĘ Why design flux stays almost same over the last few decades? ¬†‚ÄĘ Membrane oxygenation ¬†¬†¬†¬†¬†¬†¬†¬† – Fundamental issues ¬†¬†¬†¬†¬†¬†¬†¬† – Water vapor transfer modeling¬† ¬†‚ÄĘ How misinformation is born and extends its life ¬†

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