Fabrication optimization of polyethersulfone adsorptive mixed matrix membrane for enhanced dynamic methylene blue removal: Response surface methodology approach

Abstract

AbstractIn the present study, the polyethersulfone (PES)/graphene oxide (GO)/polyethylene glycol 200 (PEG‐200) adsorptive mixed matrix membranes (AMMMs) were fabricated using a non‐solvent induced phase inversion method. According to the design of experiments using response surface methodology (RSM), PES concentration (15, 17.5, and 20%), PEG‐200 concentration as a pore former additive (0.5, 2.5, and 4.5%), and GO nanosheet loading percent (0, 0.5, and 1%) were varied during fabrication. A green solvent, dimethyl sulfoxide, was used as an alternative to conventional solvents, while it exhibited better membrane performance. Methylene blue (MB) removal was optimized in PES AMMM synthesis using RSM. Attenuated total reflectance Fourier transform infrared spectroscope confirmed the presence of GO functional groups in the optimum membrane. Scanning electron microscopy analysis revealed the optimum membrane was thicker than the neat membrane and atomic force microscopy analysis demonstrated higher surface roughness. The membranes hydrophilicity increased, with a decrease in water contact angle from 61.1 ± 0.2° (neat PES) to 54.4 ± 0.9° (optimal membrane). Pure water flux of 524.8 L m−2 h−1 and MB rejection of 97.46% were obtained for the optimum membrane. Furthermore, the optimum PES AMMM demonstrated a greater dynamic adsorption capacity in comparison to the unmodified PES membrane.Highlights The optimization of the polyethersulfone (PES) adsorptive mixed matrix membranes (AMMM) for methylene blue removal was performed utilizing the response surface methodology. The calculation of the dynamic adsorption capacity (DAC) was performed through the breakthrough curves. The integration of graphene oxide into the AMMM resulted in an enhanced DAC of the AMMM. The PES AMMM performance is based on Donnan electrostatic exclusion.