Cross-Flow Filtration In the cross-flow filtration arrangement, feed flows in the
parallel direction to the membrane surface. Most of the retained particles or the
solutes are swept away with the flowing feed side liquid. Recirculation of the
retentate to enhance the concentration can be achieved in this arrangement. This
flow pattern involves less or negligible accumulation of solid particles on the
membrane and is favored.
2.2 Concentration-Driven Membrane Separation Processes
Concentration-driven membrane separation processes are the membrane separation
processes where concentration is the driving force [1]. The concentration and
pressure-driven membrane separation processes are similar in function with only
difference that in concentration-driven membrane separation processes the
permeant’s chemical activity remains the same on the feed side and decreases
drastically on the permeate side. However, in case of pressure-driven membrane
separation processes, the chemical activity of the permeant increases on the feed side
on application of increased pressure. Gas separation, pervaporation, and dialysis are
some of the common examples of concentration-driven membrane separation processes [1, 2]. Figure 3 represents a concentration-driven membrane separation
process.
Fig. 3 Schematic representation of concentration-driven membrane separation process
(Pervaporation) [1] (Reproduced with permission from Taylor and Francis)
Membrane Technology in Bioprocess Engineering
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