Performance evaluation of nanofiltration membranes for diafiltration of dye/salt mixtures: Experimental observations and model verification

Abstract

The process of desalination of aqueous dye-salt solutions by polymeric nanofi ltration membranes using commercially available modules were studied.

The experimental part was focused on determination of basic characteristics of tested membranes (Esna 1, Desal 5DK, NF 70, NF 90, NF 270 and TR 60), which above all, means determination of the dependence of permeate fl ow intensity or rejection on pressure difference used. The demineralised water and water solution of NaCl are used to characterize all of the tested membranes.

Great interest is also attached to the mathematical modelling of nanofi ltration and description of discontinuous diafi ltration by periodically adding solvent at constant pressure difference.

Keywords:

• Nanofi ltration
• Diafi ltration
• Reactive dyes
• Dye desalination