Phenol removal process development from synthetic wastewater solutions using a polymer inclusion membrane

This paper presents the results concerning the first use of a polymer inclusion membrane (PIM) for the removal and transport of phenol from an aqueous solution and polluted water. The PIM contains Cyanex 923 as the carrier, cellulose triacetate (CTA) as the base polymer, and o-nitrophenyl pentyl ether (ONPPE) as a plasticizer. The effects of variables on the transport percentage of phenol have been studied. These variables include the concentration of the carrier and the plasticizer in the membrane, pH of the aqueous phase, and the concentration of NaOH in the stripping phase. This study shows that PIM composition has a great influence in phenol recovery, while the pH of the feed phase is a determining factor for the transport of phenol. In optimal conditions (PIM: 1 cm3 ONPPE/g CTA, 0.5 M of Cyanex 923; feed phase: pH 2; stripping phase: NaOH 0.25 M), it is possible to transport 85% of phenol present in both the water lab feed phase and polluted water. Chemical oxygen demand (COD) shows that only 4.3% of organic compounds other than phenol are transported to the stripping phase, which indicates that the process is highly discriminative for phenol, even in extremely contaminated water.