Novel activated biochar-enhanced superhydrophilic nanofibrous membrane for superior oil-in-water emulsion separation

• Published in: Journal of membrane science Vol. 700; p. 122675
• Main Authors: Faraji, Mehdi, Saidi, Majid, Abdouss, Majid
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2024
• Subjects: Activated biochar; Electrospinning; Nanofibrous membrane; Oil/water separation; Superhydrophile; Electrospinning; Oil/water separation; Nanofibrous membrane; Superhydrophile; Activated biochar
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2024.122675

In this research, a high-performance Polyamide 6/Polyvinyl Alcohol/Activated biochar (PA6/PVA/AB) composite nanofibrous membrane was developed for effective separation of oil-in-water emulsions. The membrane was produced by blend electrospinning of Polyamide 6 (PA6), Polyvinyl Alcohol (PVA), and Activated biochar (AB) derived from peanut shell biomass. Glutaraldehyde (GA) cross-linking was applied to enhance stability in aqueous environments to prevent PVA swelling. The resulting nanofibrous membrane exhibited a cost-effective design with a superhydrophilic/underwater superoleophobic surface (WCA of 0° and UWOCA of 164°), a porous structure (93% porosity), and robust mechanical properties (Tensile strength: 7.73 MPa, Young modulus: 45 MPa). Optimization of the membrane composition, with 5%wt. PVA and 2%wt. AB relative to the total polymer weight in the electrospinning solution, yielded a superhydrophilic membrane capable of withstanding 2 bar pressure. Pure water flux measurements in the pressure range of 0.5–2 bar demonstrated a high permeability of 1727.5 LMH/bar and a pure water flux of 3455 LMH. The PA6/PVA/AB composite membrane exhibited exceptional performance in separating non-surfactant (NS) and surfactant-stabilized (SS) toluene-in-water emulsions (separation flux: 2006 LMH, oil rejection: 99.52%). Furthermore, it demonstrated high efficiency in the separation of SS oil-in-water emulsions of different types of oil (separation flux >1800 LMH, oil rejection >98%). The membrane's durability and chemical stability were confirmed through 15 cycles of oil-in-water emulsion separation, showcasing anti-fouling properties and reusability (separation flux >833, Oil rejection >97%). Considering its superior performance in oil-in-water emulsion separation and robust reusability, the developed nanofibrous membrane holds significant promise for practical applications. [Display omitted] •Novel Polyamide 6/Polyvinyl Alcohol/Activated Biochar composite nanofibrous membrane.•Combining Polyamide 6, Polyvinyl Alcohol, and Activated Biochar derived from peanut shell biomass by blend electrospinning.•Cross-linking Polyvinyl Alcohol with glutaraldehyde, to enhance the stability of membrane in aqueous environments.•Superior performance in separation of non-surfactant and surfactant-stabilized oil-in-water emulsions.•Highly promising nanofibrous membrane with antifouling and reusability properties.