Rejection of trace organic pollutants with high pressure membranes (NF/RO)

This article presents a modeling approach for the rejection of trace organic pollutants in high‐pressure membranes. The rejection values of uncharged organic solutes with a wide range of solute size and hydrophobicity are determined. Sigmoidal rejection curves are constructed and modeled for solutes of different hydrophobicity. The model is based on a log‐normal pore size distribution model. A model is also presented to model the rejection of charged organic solutes, based on the rejection of uncharged solutes and the concept of a “charge concentration polarization.” Moreover, scale‐up issues arising when translating results from bench‐scale units to full‐scale plants are addressed, by assessing the viability of a full‐scale rejection model. The full‐scale model is based on a convection‐diffusion model for the transport of organic solutes through the high‐pressure membranes and the use of mass balances in the system.