Reverse osmosis separations of aldehydes, ketones, and ethers in aqueous solutions using porous cellulose acetate membranes

Reverse osmosis data for a number of aldehyde, ketone, and ether solutes whose polar parameters Σσ* lie in the ranges of −0.2 to 0.6, −0.4 to 0.6, and −0.49 to 0.6, respectively, have been analyzed. The results show that solute transport parameters can be expressed as a function of steric parameters ΣEs only for ethers, polar parameter Σσ* only for aldehydes, and both ΣEs and Σσ* for ketones. The numerical values of the functional proportionality constants ρ* and δ* associated with Σσ* and ΣEs respectively, for the above class of solutes have been determined for operating pressures up to 500 psig, and a method of predicting solute separation from data on any reference solute only in each class has been established. The data on solute transport parameters for ethers, aldehydes, and ketones have been correlated with the corresponding data for sodium chloride through appropriate link constants. Analysis of data on mixed solute systems involving aldehydes and ketones show that the solutes behave independently in reverse osmosis.