Analysis of the Flux Performance of Different RO/NF Membranes in the Treatment of Agroindustrial Wastewater by Means of the Boundary Flux Theory Ochando Pulido, Javier Miguel Martínez Férez, Antonio Stoller, Marco Boundary flux Reverse osmosis Nanofiltration Olive mill wastewater Membrane pretreatments Wastewater reclamation Dynamic membrane system behaviour must be adequately addressed to avoid process unfeasibility. The lack of proper analysis will mean relying on erroneous permeate flux values in the system design, which will lead to quick and/or steady high fouling rates. In this paper, the authors present additional data supporting the boundary flux theory as a helpful tool for membrane engineers to carefully avoid process failures. By fitting the dynamic permeate flux data to the boundary flux model, it was possible to calculate the fouling index for the three selected membranes (one nanofiltration (NF) and two reverse osmosis (RO) ones). The dynamic flux given by the low-pressure RO membrane did not follow sub-boundary operating conditions, since a sharp flux loss was measured throughout the whole operating cycle, pinpointing that supra-boundary flux conditions were governing the system. This was supported by the calculated value of the fouling parameter, which resulted to be in the order of ten times higher for this membrane. However, the values of !0 for the SC-RO and DK-NF ones, supported by the very low value of the sub-boundary fouling parameter α (0.002 and 0.007 L.h-1.m-2.bar-2, respectively), ensure nearly boundary operating conditions for these membranes. 2019-05-03T15:21:14Z 2019-05-03T15:21:14Z 2018-12-26 info:eu-repo/semantics/article Ochando-Pulido, J.M.; Martínez-Férez, A.; Stoller, M.. Analysis of the Flux Performance of Different RO/NF Membranes in the Treatment of Agroindustrial Wastewater by Means of the Boundary Flux Theory.Membranes 2019, 9, 2; [doi:10.3390/membranes9010002] 2077-0375 http://hdl.handle.net/10481/55593 10.3390/membranes9010002 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España MDPI