Rejection of phenolic derivatives in aqueous solution by an interpolymer anionic composite reverse osmosis membrane

Abstract

AbstractReverse osmosis separation for 23 phenollic derivatives was examined by an anionic charged composite membrane. The solute permeation was carried out in single‐solute aqueous solution (200 mg/L) under applied pressure of 3.92–7.85 MPa at 25°C. The correlation between the solute rejection and polar parameters for phenolic derivatives has been investigated. For p‐alkylphenols, the solute rejection increased with molecular weight and/or molecular branching. In undissociated state, the rejection of phenolic derivatives was closely related with the Taft's number and the Hammett's number of substituents. Also rejections of phenolic derivatives depended upon the pH value of feed soultion and the polar effect of substituted groups. For example, rejections of aminophenols showed the minimum value at a certain pH value and on either side of the minimum point, the rejection of aminophenol increased. From these facts, the main factors in reverse osmosis serparation by an anionic composite membrane were discussed.