Abstract
Membranes of cellulose acetate derivatives-cyanoethyl cellulose acetate (CACN), hydroxypropyl cellulose acetate (CAHP) and cellulose acetate (CA) have been prepared. The reverse osmosis separation of aliphatic acids, alcohols and amines have been made. It was found that for n-alkyl organics, the solute rejections (Ra) firstly increased with the increase of carbon numbers of n-alkyl organics and reached a maximum when the organic molecule contained about three carbon atoms, and then decreased or kept stable. The order of solute rejections for organics with different structures was n-< iso--sec-<tert-because of the steric hindrance. The effect of oprating pressure on the properties of reverse osmosis have also been investigated and it was found that the solute rejections and the fluxes of solution increased with the increas of the operating pressure in the experimental extent. An 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
