title: Fouling control in a lab-scale MBR system: Comparison of several commercially applied coagulants.
abstract: The Membrane bioreactors (MBRs) integrate the biological degradation of pollutants with membrane filtration-separation during wastewater treatment. Membrane fouling, which is considered as the main process drawback, stems from the interaction between the membrane material and the (organic or inorganic) foulants, leading to membrane's efficiency deterioration. It is widely recognized that the mixed liquor colloidal and Soluble Microbial Products (SMP) are in principal responsible for this undesirable situation. As a result, the appropriate pretreatment of wastewater feed is often considered as necessary procedure and the coagulation/flocculation (C/F) process is regarded as a relevant viable option for wastewater treatment by MBRs in order to improve the effective removal of suspended solids (SS), of colloidal particles, of natural organic matter (NOM), as well as of other soluble materials. The objective of this study is the application of coagulation/flocculation for fouling control of MBR systems by using several commercially available chemical coagulant/flocculant agents. For this purpose, an appropriate lab-scale continuous-flow, fully automatic MBR system has been assembled and various (inorganic) coagulants (i.e. FeCl3∙6H2O, Fe2(SO4)3·5H2O, FeClSO4, PFS0.3, PAC A9-M, PAC-A16, Al2(SO4)3·18H2O, FO4350SSH, NaAlO2) have been examined. Filterability tests and SMP concentration measurements were also conducted in order to investigate the reversible, as well as the irreversible fouling, respectively. Based upon the obtained results and after selecting the most efficient coagulants (FeCl3·6H2O, Fe2(SO4)3·5H2O, FeClSO4, PAC-A9, PAC-A16), an attempt was subsequently performed to correlate the major fouling indices (i.e. TMP, TTF, SMP concentration) in order to improve the overall process operability by this fouling control method.
authors.affiliation: Chemical Technology and Industrial Chemistry Section, School of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
authors.forename: P K
authors.initials: PK
authors.lastname: Gkotsis
authors.affiliation: Chemical Technology and Industrial Chemistry Section, School of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
authors.forename: E L
authors.initials: EL
authors.lastname: Batsari
authors.affiliation: Chemical Technology and Industrial Chemistry Section, School of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
authors.forename: E N
authors.initials: EN
authors.lastname: Peleka
authors.affiliation: Chemical Technology and Industrial Chemistry Section, School of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
authors.forename: A K
authors.initials: AK
authors.lastname: Tolkou
authors.affiliation: Chemical Technology and Industrial Chemistry Section, School of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece. Electronic address: zoubouli@chem.auth.gr.
authors.forename: A I
authors.initials: AI
authors.lastname: Zouboulis
mesh_terms: D019149:Bioreactors; D005374:Filtration; D008567:Membranes, Artificial; D014865:Waste Disposal, Fluid; D062065:Wastewater
chemical_list: D008567:Membranes, Artificial; D062065:Wastewater
keywords: Coagulant – flocculant agents; Filterability tests; Fouling control; Membrane bioreactors; Soluble microbial products