Abstract
![CDATA[Nanofiltration has been successfully applied to the recovery of spent anion exchange brines but not yet for spent cation exchange brines. Polymeric nanofiltration membranes have ionisable carboxyl and amine functional groups and tend to carry a negative surface charge at neutral pH, which actively rejects multivalent anions (such as colourants, phosphates and citrates). However, the amphoteric nature of polymeric nanofiltration membranes should permit the manipulation of surface charge by pH, to control the rejection characteristics of the membrane. Experiments on calcium rejection as a function of pH, brine concentration, calcium concentration and anion composition using commercially available nanofiltration membranes have shown that calcium rejection was highest at acidic pH, but was adversely affected by high brine concentration and elevated calcium concentrations due to charge shielding of the membrane. Diafiltration of the feed was explored to minimise these effects and maximise monovalent cation recovery. Developments of new membranes accentuating the amphoteric nature of polymeric nanofiltration membranes should permit the manipulation of surface charge by pH, to control the rejection characteristics of the membrane and enable development of further applications.]]
| Original language | English |
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| Title of host publication | IMSTEC '03 : 5th International Membrane Science and Technology Conference, November 10-14, 2003, the University of New South Wales, Sydney, Australia |
| Publisher | UNESCO Centre for Membrane Science and Technology, University of New South Wales |
| Number of pages | 1 |
| ISBN (Print) | 0733420893 |
| Publication status | Published - 2003 |
| Event | International Membrane Science and Technology Conference - Duration: 1 Jan 2003 → … |
Conference
| Conference | International Membrane Science and Technology Conference |
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| Period | 1/01/03 → … |