Solvent impregnated resins for the removal of low concentration phenol from water

The focus of this investigation is the development of a solvent impregnated resin for phenol removal from dilute aqueous solutions. Using a solvent impregnated resin (SIR) eliminates the problem of emulsification encountered in liquid–liquid extraction. Impregnated MPP particles and impregnated XAD16 particles are successfully used for phenol extraction. Impregnated MPP particles are preferred, as impregnated XAD16 particles show less mechanical strength and are more expensive. Impregnated MPP particles perform better compared to other synthetic adsorbents and basic ion exchangers. The maximum phenol capacity of impregnated MPP particles with 0.99 mol Cyanex 923 kg-1 SIR is 4.1 mol kg-1 SIR (386 mg g-1 SIR) and of MPP particles containing 1.47 mol Cyanex 923 kg-1 SIR it is 5.08 mol kg-1 SIR (478 mg g-1 SIR). The regenerability of impregnated MPP particles is easy and complete, and the particles are stable during several cycles. The equilibrium constants for the extraction of phenol are determined as Kchem = 37 L mol-1 and Kphys = 18 (mol L-1) (mol L-1)-1. With these values the SIR isotherms can be satisfactorily described. The results indicate that SIR technology is a promising alternative for the conventional phenol removal technologies at low phenol concentration levels.