Submerged membranes system

Another setup used for the hydrogenation of DMI with Ru-BINAP was equipped with dense PDMS elastomer membranes (Jacobs et al. [48]). The catalyst solution was present in a submerged membrane system, prepared as a sealed PDMS capsule . The catalytically active complex was retained by the membrane while substrate and products, dissolved in the bulk phase, could cross the membrane under the influence of the concentration difference without the need for mechanical pressure. 

Over the past decade, there has been an upsurge of interest in the use of gas bubbles to enhance membrane processes. The typical applications include two-phase flow filtration with tubular membranes and submerged membrane systems. A major stimulus for the latter has been the development of MBRs. 

Fig. 7 Submerged membrane systems for wastewater treatment. (View this art in color at www.dekker.com.)...

The membranes selected for cost estimates are the MF PVDF, the UF CA, and the NF PA. The selection was based on the comparabilitj to membrane materials used in this study. The cost for MF is high, but PVDF is chosen as this appears to be the best membrane material despite other materials being installed currently. For polypropylene the cost will be about one third of the estimate and possibly lower for a submerged membrane system (Johnson (1999)). 

Figure 3.51 Submerged membrane system process flow sheet. Source USFilter.

The catalyst deposition on the membrane surface and fouling caused flux decUne during the photocatalytic process. To overcome these problems the depressurized (submerged) membrane system, in which the membrane module was located separately from the photoreactor, was studied. The achieved results showed pharmaceuticals abatement of 100% after ca. 20 min and mineralization of 44.5% after ca. 150 min in the retentate. The UF membrane used in the submerged system did not allow the rejection of GEM and of its oxidation products compared to the NF membranes of the pressurized system. 

Figure 6.5 Immersed/submerged membrane system (Zenon 500 process).

Figure 9.5 Submerged membrane system (inside aeration tank).

Figure 9.6 Submerged membrane system (in an external filtration tank).

Kim, J. S., and Lee, C. H. (2003). Effect of powdered activated carbon on the performance of an aerobic membrane bioieactor Comparison between cross-flow and submerged membrane systems. Water Environ. Res. 75, 300-307. 

Figure 10.1 Schematic showing common features of submerged membrane system.

Huber The Huber MBR is radically different from aU other commercial submerged membrane systems, being based on a mechanically moved membrane. The Huber VRM (vacuum rotating membrane) uses flat-sheet membranes of polyethersulfone... 

The amount of air sparging required to control fouling in submerged membrane systems is an important operating cost. This is because the power required, P i, is a function of the... 

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