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. (C) 2008 American Institute of Chemical Engineers Environ Prog.