title: Solute transport model for trace organic neutral and charged compounds through nanofiltration and reverse osmosis membranes.
abstract: Rejection of trace organic compounds, including disinfection by-products (DBPs) and pharmaceutical active compounds (PhACs), by high-pressure membranes has become a focus of public interest internationally in both drinking water treatment and wastewater reclamation/reuse. The ability to simulate, or even predict, the rejection of these compounds by high-pressure membranes, encompassing nanofiltration (NF) and reverse osmosis (RO), will improve process economics and expand membrane applications. The objective of this research is to develop a membrane transport model to account for diffusive and convective contributions to solute transport and rejection. After completion of cross-flow tests and diffusion cell tests with target compounds, modeling efforts were performed in accordance with a non-equilibrium thermodynamic transport equation. Comparing the percentages of convection and diffusion contributions to transport, convection is dominant for most compounds, but diffusion is important for more hydrophobic non-polar compounds. Convection is also more dominant for looser membranes (i.e., NF). In addition, higher initial compound concentrations and greater J(0)/k ratios contribute to solute fluxes more dominated by convection. Given the treatment objective of compound rejection, compound transport and rejection trends are inversely related.
authors.affiliation: University of Colorado at Boulder, 1111 Engineering Dr., ECOT 441, Boulder, CO 80309, USA.
authors.forename: Tae-Uk
authors.initials: TU
authors.lastname: Kim
authors.forename: Jörg E
authors.initials: JE
authors.lastname: Drewes
authors.forename: R
authors.initials: R
authors.lastname: Scott Summers
authors.forename: Gary L
authors.initials: GL
authors.lastname: Amy
mesh_terms: D018481:Convection; D004058:Diffusion; D007700:Kinetics; D008567:Membranes, Artificial; D008956:Models, Chemical; D036103:Nanotechnology / Q000379:methods*; D009930:Organic Chemicals / Q000737:chemistry*; D009995:Osmosis; D014462:Ultrafiltration / Q000379:methods*; D018508:Water Purification / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D009930:Organic Chemicals