The discharge of industrial oily wastewater and oil spill accidents has resulted in significant environmental pollution, creating an urgent need for the treatment of oily wastewater. Nanofiber membranes, known for their high stability, flux, and efficiency, are widely employed in oil–water separation. This study systematically compared the performance of polyacrylonitrile/ graphene oxide (PAN/GO) composite nanofiber membranes prepared through immersion and electrospinning methods for oily wastewater treatment. Experimental findings demonstrated that immersion-prepared membranes achieved high flux (772.9 ± 2.9 L·m−2·h−1, n-hexane/water mixture) and efficiency (98.8%) at a GO concentration of 1.0 g/mL. On the other hand, electrospinning-prepared membranes exhibited superior flux (1500.3 ± 4.4 L·m−2·h−1, n-hexane/water mixture) and efficiency (99.6%) at a higher GO concentration (1.5 g/mL). This membrane displayed excellent stability, maintaining their exceptional performance even after ten cycles of separation. This study compared the advantages and disadvantages of the two methods for preparation of PAN/GO composite nanofiber membrane, offering valuable guidance for practical applications.

Preparation of PANGO composite nanofiber membrane for oil-containing wastewater treatment
    Abstract
    1 Introduction
    2 Experimental
        2.1 Material and chemicals
        2.2 Synthesis of GO power
        2.3 Fabrication of PAN and NPAN membranes
        2.4 Synthesis of PGO and NPGO composite membrane by immersion method
        2.5 Synthesis of PGO and NPGO composite membrane by electrospinning
        2.6 Characterization
        2.7 Oil–water separation and circulation separation experiment
    3 Results and discussion
        3.1 Characterization
        3.2 Influence of preparation process on membrane separation performance
        3.3 Effect of alkali pretreatment method on membrane separation performance
        3.4 Membrane stability
    4 Conclusion
    References

• Tong Lu(Key Laboratory for Green Chemical Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, School of Materials Science and Engineering, Novel Catalytic Materials of Hubei Engineering Research Center, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China)
• Qingxia Zhang(Key Laboratory for Green Chemical Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, School of Materials Science and Engineering, Novel Catalytic Materials of Hubei Engineering Research Center, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China)
• Jingjing Yang(Key Laboratory for Green Chemical Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, School of Materials Science and Engineering, Novel Catalytic Materials of Hubei Engineering Research Center, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China)
• Yue Xin(Key Laboratory for Green Chemical Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, School of Materials Science and Engineering, Novel Catalytic Materials of Hubei Engineering Research Center, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China)
• Zhilei Zhang(Key Laboratory for Green Chemical Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, School of Materials Science and Engineering, Novel Catalytic Materials of Hubei Engineering Research Center, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China)
• Lingye Hu(Faculty of Engineering, The University of Sydney, Sydney, NSW 2008, Australia)
• Jing Hu(Key Laboratory for Green Chemical Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, School of Materials Science and Engineering, Novel Catalytic Materials of Hubei Engineering Research Center, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China)
• Qin Qin(Key Laboratory for Green Chemical Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, School of Materials Science and Engineering, Novel Catalytic Materials of Hubei Engineering Research Center, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China)
• Hao Yang(Key Laboratory for Green Chemical Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, School of Materials Science and Engineering, Novel Catalytic Materials of Hubei Engineering Research Center, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China) Corresponding author