title: Effect of C/N shock variation on the performances of a moving bed membrane bioreactor.
abstract: The effect of a sharp variation of C/N ratio in a moving bed membrane bioreactor (MB-MBR) pilot plant treating high strength wastewater has been investigated. The experimental campaign was divided into two periods, each characterized by a different C/N ratio (namely, 2.5 and 15, Period 1 and Period 2, respectively). The MB-MBR system was analyzed in terms of organic carbon removal, nitrification efficiency, biokinetic activity and fouling behavior. The results showed that the nitrification process was severely affected by lower C/N value and by high concentration of ammonia. It was noticed an extensive stress effect on the autotrophic bacteria. Furthermore, it was observed an increase of the resistance related to particle deposition into membrane pores, likely due to a worsening of the cake layer features, with a reduction of the "pre-filter" effect, also related to the increase of the total Extracellular Polymeric Substances production with the C/N ratio.
authors.affiliation: Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali - Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy. Electronic address: daniele.ditrapani@unipa.it.
authors.forename: Daniele
authors.initials: D
authors.lastname: Di Trapani
authors.affiliation: Facoltà di Ingegneria e Architettura - Università di Enna "Kore", Cittadella Universitaria, 94100 Enna, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Di Bella
authors.affiliation: Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali - Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Mannina
authors.affiliation: Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali - Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Torregrossa
authors.affiliation: Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali - Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy.
authors.forename: Gaspare
authors.initials: G
authors.lastname: Viviani
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism; D018441:Biofilms; D057219:Biofouling; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D001704:Biopolymers / Q000378:metabolism; D019149:Bioreactors; D002244:Carbon / Q000032:analysis*; D008567:Membranes, Artificial; D009584:Nitrogen / Q000032:analysis*; D010084:Oxidation-Reduction; D010865:Pilot Projects; D014865:Waste Disposal, Fluid
chemical_list: D001704:Biopolymers; D008567:Membranes, Artificial; D002244:Carbon; D000641:Ammonia; D009584:Nitrogen
keywords: C/N ratio; Moving bed membrane bioreactor; Nitrification; OLR