title: Evaluation of membrane fouling for in-line filtration of oil sands process-affected water: the effects of pretreatment conditions.
abstract: Membrane filtration is an effective reclamation option for oil sands process-affected water (OSPW). However, fresh OSPWs contain suspended solids and inorganic constituents in suspended and dissolved forms that can severely foul membranes. Pretreatment of OSPW with coagulation-flocculation (CF) was investigated to determine the effects of different coagulant aids (anionic, cationic, and nonionic polymers) on membrane surface properties and fouling. Our results showed that CF pretreatment effectively enhanced nanofiltration (NF) and reverse osmosis (RO) membrane permeate flux and salt rejection ratio through reducing membrane fouling. It was shown that coagulants and coagulant aids applied to OSPW feedwater can affect membrane physicochemical properties (surface hydrophilicity, zeta potential, and morphology), membrane performance, and the fouling indexes. Membrane rejection of ionic species increased significantly with the inclusion of an anionic coagulant aid and slightly with a cationic coagulant aid. Among three coagulant aids tested, anionic coagulant aids led to the most enhanced membrane performance through increasing membrane surface negativity and decreasing the formation of a fouling layer. Conversely, although cationic coagulant aids were the most effective in reducing OSPW turbidity, the application of cationic coagulant aids promoted the adsorption of foulants on membrane surfaces.
authors.affiliation: Department of Civil and Environmental Engineering,  University of Alberta , Edmonton, Alberta, CanadaT6G 2W2.
authors.forename: Eun-Sik
authors.initials: ES
authors.lastname: Kim
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Mohamed
authors.initials: M
authors.lastname: Gamal El-Din
mesh_terms: D057219:Biofouling; D004777:Environment; D005374:Filtration / Q000379:methods*; D005427:Flocculation; D007477:Ions; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D009821:Oils / Q000737:chemistry*; D010539:Permeability; D012822:Silicon Dioxide / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D012996:Solutions; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
chemical_list: D007477:Ions; D008567:Membranes, Artificial; D009821:Oils; D012996:Solutions; D012965:Sodium Chloride; D012822:Silicon Dioxide