Modeling of the Adsorption of Organic Compounds on Polymeric Nanofiltration Membranes in Solutions Containing Two Compounds

The adsorption of organic compounds in aqueous solution on polymeric nanofiltration membranes is studied; this process is one of the most important fouling mechanisms influencing the flux and retention behavior of nanofiltration membranes. It is shown that the adsorption of dissolved organic compounds on polymeric nanofiltration membranes is comparable to that on activated carbon. Freundlich and Langmuir isotherms are used to describe the relation between the adsorbed mass on the membrane and the equilibrium concentration of the organic compound in a single‐compound solution. Based on these results, three models for the adsorption of solutions containing several compounds [i.e., the simple competitive adsorption model (SCAM), the model of Jain–Snoeyinck, and the model of Butler–Ockrent] were used to predict the adsorption behavior of an organic compound in an aqueous solution containing two compounds. The results of the three models were compared to experimental observations. It is shown that the SCAM allows a good prediction of the adsorption behavior. Nanofiltration is one of the most promising techniques for producing high‐quality drinking water. However, the performance of the polymeric membranes used in this process can be seriously affected by the presence of organic adsorbats. It is shown that the simple competitive adsorption model (SCAM) predicts the real adsorption behavior quite well (see figure; q90=mass of benzylidene acetone adsorbed on an N30F membrane, C90=equilibrium concentration).