The solution-diffusion and Spiegler-Kedem transport models were fit to experimentally measured 𝑅 %&' and 𝐽 ! to further characterise the investigated system. The widely applied solution-diffusion model assumes diffusion as the sole transmembrane molecular transport mechanism, and is derived from Henry's law and Fick's first law of diffusion. However, the solution-diffusion model may fail to characterise a separation system if the transmembrane passage of solute is affected by convection, which could be due to an intrinsic feature of the membrane or stem from less selective flow through inherently present defects. The Spiegler-Kedem equations, which are derived from irreversible thermodynamics, contain a convective contribution to the solute flux in their description of mass transfer. Assuming constant model parameters and considering concentration polarisation according to Eq. 7, the transport model equations employed in this study are given as: