title: Towards integrated operation of membrane bioreactors: effects of aeration on biological and filtration performance.
abstract: Two experimental studies evaluated the effect of aerobic and membrane aeration changes on sludge properties, biological nutrient removal and filtration processes in a pilot plant membrane bioreactor. The optimal operating conditions were found at an aerobic dissolved oxygen set-point (DO) of 0.5 mg O2 L(-1) and a membrane specific aeration demand (SADm) of 1 m h(-1), where membrane aeration can be used for nitrification. Under these conditions, a total flow reduction of 42% was achieved (75% energy reduction) without compromising nutrient removal efficiencies, maintaining sludge characteristics and controlled filtration. Below these optimal operating conditions, the nutrient removal efficiency was reduced, increasing 20% for soluble microbial products, 14% for capillarity suction time and reducing a 15% for filterability. Below this DO set-point, fouling increased with a transmembrane pressure 75% higher. SADm below 1 m h(-1) doubled the values of transmembrane pressure, without recovery after achieving the initial conditions.
authors.affiliation: LEQUiA, Institute of the Environment, University of Girona, E17071 Girona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Dalmau
authors.affiliation: LEQUiA, Institute of the Environment, University of Girona, E17071 Girona, Spain.
authors.forename: H
authors.initials: H
authors.lastname: Monclús
authors.affiliation: LEQUiA, Institute of the Environment, University of Girona, E17071 Girona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Gabarrón
authors.affiliation: LEQUiA, Institute of the Environment, University of Girona, E17071 Girona, Spain; ICRA, Catalan Institute for Water Research, Scientific and Technological Park of the University of Girona, H2O Building, EmiliGrahit 101, E17003 Girona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Rodriguez-Roda
authors.affiliation: LEQUiA, Institute of the Environment, University of Girona, E17071 Girona, Spain. Electronic address: joaquim.comas@udg.edu.
authors.forename: J
authors.initials: J
authors.lastname: Comas
mesh_terms: D000388:Air; D019149:Bioreactors; D005374:Filtration / Q000379:methods / Q000592:standards*; D008567:Membranes, Artificial; D058465:Nitrification; D012722:Sewage / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D012722:Sewage
keywords: Aeration; Biological nutrient removal; Energy savings; Fouling; Membrane bioreactors