title: Start-up of two moving bed membrane bioreactors treating saline wastewater contaminated by hydrocarbons.
abstract: This work aims to assess the acclimation of microorganisms to a gradual increase of salinity and hydrocarbons, during the start-up of two moving bed membrane bioreactors (MB-MBRs) fed with saline oily wastewater. In both systems an ultrafiltration membrane was used and two types of carriers were employed: polyurethane sponge cubes (MB-MBRI) and polyethylene cylindrical carriers (MB-MBRII). A decreasing dilution factor of slops has been adopted in order to allow biomass acclimation. The simultaneous effect of salinity and hydrocarbons played an inhibitory role in biomass growth and this resulted in a decrease of the biological removal efficiencies. A reduction of bound extracellular polymeric substances and a simultaneous release of soluble microbial products (SMPs) were observed, particularly in the MB-MBRII system, probably due to the occurrence of a greater suspended biomass stress as response to the recalcitrance of substrate. On the one hand, a clear attachment of biomass occurred only in MB-MBRI and this affected the fouling deposition on the membrane surface. The processes of detachment and entrapment of biomass, from and into the carriers, significantly influenced the superficial cake deposition and its reversibility. On the other hand, in MB-MBRII, the higher production of SMPs implied a predominance of the pore blocking.
authors.affiliation: Facoltà di Ingegneria e Architettura, Università degli studi di Enna ''Kore'', Cittadella Universitaria, 94100 Enna, Italy E-mail: riccardo.campo@unikore.it.
authors.forename: R
authors.initials: R
authors.lastname: Campo
authors.affiliation: Facoltà di Ingegneria e Architettura, Università degli studi di Enna ''Kore'', Cittadella Universitaria, 94100 Enna, Italy E-mail: riccardo.campo@unikore.it.
authors.forename: N
authors.initials: N
authors.lastname: Di Prima
authors.affiliation: Facoltà di Ingegneria e Architettura, Università degli studi di Enna ''Kore'', Cittadella Universitaria, 94100 Enna, Italy E-mail: riccardo.campo@unikore.it.
authors.forename: G
authors.initials: G
authors.lastname: Freni
authors.affiliation: Facoltà di Ingegneria e Architettura, Università degli studi di Enna ''Kore'', Cittadella Universitaria, 94100 Enna, Italy E-mail: riccardo.campo@unikore.it.
authors.forename: M G
authors.initials: MG
authors.lastname: Giustra
authors.affiliation: Facoltà di Ingegneria e Architettura, Università degli studi di Enna ''Kore'', Cittadella Universitaria, 94100 Enna, Italy E-mail: riccardo.campo@unikore.it.
authors.forename: G
authors.initials: G
authors.lastname: Di Bella
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D006838:Hydrocarbons / Q000378:metabolism*; D008567:Membranes, Artificial; D054712:Salinity; D012965:Sodium Chloride / Q000378:metabolism; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D006838:Hydrocarbons; D008567:Membranes, Artificial; D012965:Sodium Chloride; D062065:Wastewater; D014874:Water Pollutants, Chemical