Impact of solvents and process conditions on the formation of polyethersulfone membranes and its fouling behavior in lake water filtration

Abstract

BACKGROUND: The existence of natural organic colloids causes membrane fouling, which decreases the flux rate. Hence, membrane modification and lake water pretreatment were carried out to improve membrane performance. In this study, important preparation parameters such as solvents (N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP)), coagulant bath temperature (CBT) (10, 20 and 30 ∘ C) and coagulant (sodium dodecyl sulfate SDS): 0.5, 1.0 and 1.5 g L −1 ) were optimized for the fabrication of high flux polyethersulfone (PES) membrane. Cloisite was used for the pretreatment of lake water. RESULTS:The highest water permeability and pore radius of 393.03 × 10 −9 m s −1 kPa −1 and 4.43 nm, respectively, were observed for the PES/DMAc membrane combination at coagulant bath temperature of 10 ∘ C and non-solvent containing 1.5 g L −1 SDS solution. Morphology analysis also displayed large pore size and macrovoid formation for such combination. Pretreated lake water had highest natural organic matter (NOM) rejection of 93% for PES/DMF membrane made at a coagulant bath temperature of 20 ∘ C and non-solvent containing water. CONCLUSION: High flux PES membrane formation is achieved through the DMAc solvent with SDS as non-solvent solution at lower coagulation bath temperature. Pretreated lake water showed an increase of membrane flux and fouling resistance. Performance of lower MWCO membranesAmong the LMWCO membranes, CBT1 and S4 membrane have the highest average flux of 29.93 and 13.15 L m −2 h −1 for the J Chem Technol Biotechnol 2016; 91: 2568-2581

Potential of DMSO as greener solvent for PES ultra‐ and nanofiltration membrane preparation

“…With average contact angles between 63.0° and 73.7°, all membranes were relatively hydrophilic. This is in the expected range for PES membranes . The hydrophobicity of the membrane surface appeared to increase slightly with increasing PES concentration.…”

“…The affinity between solvent and polymer is defined by the following formula: with P standing for polymer and S standing for solvent. Table gives an overview of the necessary solubility parameters from the literature …”

Harvesting of microalgae Coelastrella sp. FI69 using pore former induced TiO2 incorporated PES mixed matrix membranes

“…The enhancement of flux is due to the increase of surface porosity and hydrophilic property of the membrane surface. The non‐solvent SDS solution possesses amphiphilic groups which promote faster precipitation and improve the surface porosity of the membrane . Furthermore, the combination of hydrophilic polymer and TiO 2 significantly improves the hydrophilic property of the membrane surface.…”

Concentration of whey protein from cheese whey effluent using ultrafiltration by combination of hydrophilic metal oxides and hydrophobic polymer

“…Initially, nano metal oxides and PES polymers were dried in a hot air oven at 60 °C for 12 h. The nano metal oxides and PES compositions and corresponding membrane labels are provided in Table . In the earlier studies, membrane formation conditions were optimized for high flux rate . Based on the earlier studies, solvent and coagulant bath conditions were chosen for the preparationof MMMs.…”