title: On The Relationship between Suspended Solids of Different Size, the Observed Boundary Flux and Rejection Values for Membranes Treating a Civil Wastewater Stream.
abstract: 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.
authors.affiliation: Department of Chemical Materials Environmental Engineering, University of Rome "La Sapienza", Via Eudossiana 18, Rome 00184, Italy. marco.stoller@uniroma1.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Stoller
authors.affiliation: Chemical Engineering Department, University of Granada, Granada 18071, Spain. jmochandop@ugr.es.
authors.forename: Javier Miguel Ochando
authors.initials: JM
authors.lastname: Pulido
authors.affiliation: Department of Chemical Materials Environmental Engineering, University of Rome "La Sapienza", Via Eudossiana 18, Rome 00184, Italy. luca.dipalma@uniroma1.it.
authors.forename: Luca Di
authors.initials: LD
authors.lastname: Palma
references.citation: Environ Technol. 2008 May;29(5):591-601
references.pmid: 18661743
references.citation: Adv Colloid Interface Sci. 2011 May 11;164(1-2):38-44
references.pmid: 21353191
references.citation: ScientificWorldJournal. 2014 Jan 29;2014:656101
references.pmid: 24592177
references.citation: Membranes (Basel). 2013 Jul 11;3(3):126-35
references.pmid: 24956941