Influence of Membrane Material on Permeability and Solute Rejection

2 Influence of Membrane Material on Permeability and Solute Rejection 

The influence of metal oxide derived membrane material with regard to permeability and solute rejection was first reported by Vernon Ballou et al. [42,43] in the early 70s concerning mesoporous glass membranes. Filtration of sodium chloride and urea was studied with porous glass membranes in close-end capillary form, to determine the effect of pressure, temperature and concentration variations on lifetime rejection and flux characteristics. In this work experiments were considered as hyperfiltration (reverse osmosis) due to the high pressure applied to the membranes, 40 to 120 atm. In fact, results reproduced in Table 12.3 show that these membranes do not behave as h)qjerfiltra-tion membranes but as membranes with intermediate performances between ultra- and nanofiltration in which surface charge effect of metal oxide material plays an important role in solute rejection. 

Rejection data for NaCl were explained according to a low-capacity ion exchange mechanism. The ion exchange mechanism put forward in this work is not consistent with the porous structure of the membrcines and the high transmembrane pressure used in the filtration experiments. Ion exchange 

Rejection of NaCl (58.5 g mole ) and Urea (56 g mole ) using mesoporous glass membranes over a range of solute concentration, from Ref. [42] 

12 — TRANSPORT AND FOULING PHENOMENA IN LIQUID PHASE SEPARATION 

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