The reverse osmosis (RO) separation of aqueous organic solutions

such as alcohols

amines

aldehydes

acids

ketones

and esters etc.

by PAA (polyacrylic acid)/PSF (polysulfone) composite membrane has been studied. It was foundthat the separation results for aliphatic alcohols

amines and aldehydes are satisfactory

the solute rejection (Ra) and thevolume fluxes of solutions (Jv) for 1000 ppm ethanol

ethylamine and ethyl aldehyde are 66.2%

61.0%

84.0% and 0.90×10-6

0.35×10-6

0.40×10-6m3/m2·s

respectively

at 5.0 MPa and ℃.Ra increased with increasing molecular weights of alcohols

amines and aldehydes

and the Ra for n-amyl alcohol

n-butylamine and n-butyl aldehyde reached 94.3%

88.6% and 96.0%

respectively.Satisfactory separation results (Ra>70%) for ketones

esters

phenols and polyols have been obtained with the PAA/PSF composite membrane.The effect of operating pressure on the properties of reverse osmosis has also been investigated.Analysis of experimental data with Spiegler-Kedem's transport model has been carried out and the membrane constants such as reflection coefficient σ

solute and hydraulic permeabilities ω and Lp for several organic solutes have been obtained.