STUDY ON THE DESALINATION BEHAVIORS OF PA/PSF THIN FILM COMPOSITE

1. INTRODUCTION Nanofiltration (NF) membranes have been known for having properties between those of ultrafiltration (UF) membranes and reverse osmosis (RO) membranes and thus have found applications in many areas especially in rejecting multivalent ions for water softening and charged organic pollutants for wastewater treatment. Because of their advantages, such as low operating pressure, high permeate flux, high retention to multivalent ions and organic molecules with molecular weight …

STUDY ON THE DESALINATION BEHAVIORS OF PA/PSF THIN FILM COMPOSITE

A polypiperazine amide (PA)/polysulfone (PSF) thin film composite (TFC) was prepared by interfacial polymerization (IP) using a trimesoyl chloride hexane solution as the oil phase and a piperazine aqueous solution as the water phase on a porous polysulfone hollow fiber substrate. Its separating behaviors were investigated systematically to various salts such as NaCl, KCl, Na2SO4, MgCl2, CaCl2 and MgSO4, showing the highest rejection rate to Na2SO4, the second to MgSO4, the third to MgCl2 and CaCl2, and the lowest to KCl, NaCl, being 99%, 98%, 70%, 60%, 15% and 10% respectively. Under an increasing pressure or with time, the rejection rate of the TFC rises to a plateau. To various concentration of the feed, the rejection rate reduced gradually with the higher concentration.