A new phenolic hydroxyl modified polystyrene adsorbent for the removal of phenolic compounds from their aqueous solutions

A new phenolic hydroxyl modified polystyrene adsorbent (AM-1) was synthesized for the removal of phenolic compounds from their aqueous solutions. This new adsorbent can be used directly without the wetting pretreatment. A comparison of the sorption properties of the AM-1 and the commercial Amberlite XAD-4 toward four phenolic compounds, phenol, p-cresol, p-chlorophenol, and p-nitrophenol, was made. The capacities of equilibrium adsorption of AM-1 for all four phenolic compounds were around two times higher than that of Amberlite XAD-4, which may be contributed to the presence of phenol hydroxyl group on the surface and the unique pore structure of AM-1. Freundlich isotherm equations and the values of isosteric adsorption enthalpies for the four phenolic compounds indicated a physical adsorption mechanism on both adsorbents. Column studies showed that both the breakthrough adsorption capacity and the total adsorption capacity of phenol on AM-1 were higher than on Amberlite XAD-4 while less acetone was needed for desorbing phenol from AM-1 than from Amberlite XAD-4.