Separation of low volatile organic compounds, phenol and aniline derivatives, from aqueous solution using silicone rubber membrane

This paper explores the separation and recovery of 4-substituted phenol and aniline derivatives from aqueous solutions by a permeation and chemical desorption (PCD) method using a silicone rubber membrane. Phenols or anilines in aqueous solution were successfully recovered to aqueous NaOH or HCl solutions, respectively, using a flat silicone membrane apparatus. The penetration rate of 4-substituted phenols or anilines was related to the alkyl chain length. The overall mass transfer coefficient (KOL) for the phenols and anilines closely correlated with their 1-octanol/water partition coefficient (POW), and the correlations could be expressed by the separate formulas with almost equal slopes. A comparison between the method and the PV method was also experimentally performed using a tube-type apparatus, and the removal ratio of the phenols by the method is much greater than that by the pervaporation (PV) method.