Removal of 4-chloro-2-methylphenol from aqueous solutions by nanofiltration and reverse osmosis

© 2014 Balaban Desalination Publications. All rights reserved.Chloromethylphenols are typical phenolic pollutants frequently found in wastewater treatment plants and industrial landfill leachates, while pressure-driven membrane processes have been demonstrated to be a practical and competitive alternative for their removal. The performance of two membranes (an NF99 nanofiltration membrane and an RO99 reverse osmosis membrane) for removing 4-chloro-2-methylphenol (4C2MP) from synthetic solutions at different pressures, feed concentrations and feed pH values is compared in this paper using permeate flux and rejection as representative parameters. Higher permeate fluxes were obtained with the NF99 membrane but higher rates of 4C2MP rejection were obtained with the RO99 membrane. There was a substantial increase in 4C2MP rejection as the pH was increased from 8 to 11 in the case of the NF99 membrane. The results are explained by the different chemical structures of the active layers of both membranes.