On The Relationship between Suspended Solids of Different Size, the Observed Boundary Flux and Rejection Values for Membranes Treating a Civil Wastewater Stream Stoler, Marco Ochando Pulido, Javier Miguel Palma, Luca Membrane fouling Membrane selectivity Boundary flux Wastewater treatment Membrane fouling is one of the main issues in membrane processes, leading to a progressive decrease of permeability. High fouling rates strongly reduce the productivity of the membrane plant, and negatively affect the surviving rate of the membrane modules, especially when real wastewater is treated. On the other hand, since selectivity must meet certain target requirements, fouling may lead to unexpected selectivity improvements due to the formation of an additional superficial layer formed of foulants and that act like a selective secondary membrane layer. In this case, a certain amount of fouling may be profitable to the point where selectivity targets were reached and productivity is not significantly affected. In this work, the secondary clarifier of a step sludge recirculation bioreactor treating municipal wastewater was replaced by a membrane unit, aiming at recovering return sludge and producing purified water. Fouling issues of such a system were checked by boundary flux measurements. A simple model for the description of the observed productivity and selectivity values as a function of membrane fouling is proposed. 2017-02-23T11:13:28Z 2017-02-23T11:13:28Z 2014 info:eu-repo/semantics/article Stoller, M.; Pulido, J.M.O.; Palma, L.D. On The Relationship between Suspended Solids of Different Size, the Observed Boundary Flux and Rejection Values for Membranes Treating a Civil Wastewater Stream. Membranes 2014, 4, 414-423. [http://hdl.handle.net/10481/45016] 2077-0375 http://hdl.handle.net/10481/45016 spa info:eu-repo/semantics/openAccess MPDI