Electrospinning PAN/PEI/MWCNT-COOH nanocomposite fiber membrane with excellent oil-in-water separation and heavy metal ion adsorption capacity

Poor water quality caused by heavy metal ions and oil spillages are posing serious threats and risks to the environment and human health. Herein, PAN/PEI/MWCNT-COOH composite nanofiber membranes (CNMs) were successfully prepared by an electrospinning device, which could adsorb heavy metal Pb2+ ions and separate oil-in-water emulsions. The CNMs have superhydrophobicity and underwater superoleophobicity. In the oil-water separation experiment, the CNMs exhibited oil-in-water emulsions with excellent separation performance and high flux, the CNMs still had a high flux (800 L m−2 h−1) after 5 cycle tests. In the adsorption experiment, the maximum adsorption of Pb2+ ions were reached 346 mg/g, and the adsorption followed the pseudo-second-order model and the Langmuir isotherm model. After 5 adsorption-desorption cycles, the Pb2+ ion removal efficiency of the CNMs still reached more than 70 %. Based on the above advantages, this study provides new insights into the adsorption of Pb2+ ions and the efficient separation of oil-in-water emulsions.