title: Properties governing the transport of trace organic contaminants through ion-exchange membranes.
abstract: Ion exchange membranes could provide a solution to the selective separation of organic and inorganic components in industrial wastewater. The phenomena governing the transport of organics through the IEM however, are not yet fully understood. Therefore, the transport of trace organic contaminants (TOrCs) as a model for a wide variety of organic compounds was studied under different conditions. It was found that in the absence of salt and external potential, the chemical equilibrium is the main driver for TOrC-transport, resulting in the transport of mainly charged TOrCs. When salt is present, the transport of TOrCs is hampered in favor of the NaCl transport, which shows a preferential interaction with the membranes due to its small size, high mobility and concentration. It is hypothesized that electrostatic interactions and electron donor/acceptor interactions are the main drivers for TOrC transport and that transport is mainly diffusion driven. This was confirmed in the experiments with different current densities, where the external potential seemed to have only a minor influence on the transport of TOrCs. It is only when the salt becomes nearly completely depleted that the TOrCs are transported as charge carriers. This shows that it is very difficult to get preferential transport of organic compounds due to the diffusive nature of their transport.
authors.affiliation: Particle and Interfacial Technology Group, Department of Applied Analytical and Physical Chemistry, Faculty of Bioscience Engineering, Ghent University , Ghent 9000, Belgium.
authors.forename: Marjolein
authors.initials: M
authors.lastname: Vanoppen
authors.forename: Annelise F A M
authors.initials: AF
authors.lastname: Bakelants
authors.forename: Dorien
authors.initials: D
authors.lastname: Gaublomme
authors.forename: Klaas V K M
authors.initials: KV
authors.lastname: Schoutteten
authors.forename: Julie
authors.initials: J
authors.lastname: Vanden Bussche
authors.forename: Lynn
authors.initials: L
authors.lastname: Vanhaecke
authors.forename: Arne R D
authors.initials: AR
authors.lastname: Verliefde
mesh_terms: D004058:Diffusion; D007474:Ion Exchange; D008962:Models, Theoretical; D009930:Organic Chemicals / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D009930:Organic Chemicals; D062065:Wastewater; D014874:Water Pollutants, Chemical