Enhancement of filtration performance and antifouling properties of polyethersulfone membranes using Fe₃O₄@walnut shell-derived activated carbon nanocomposite for heavy metal ions removal

Effective water treatment methods are required owing to heavy metal ion contamination. The phase inversion approach was employed in this work to prepare antifouling polyethersulfone (PES)/Fe₃O₄@activated walnut shell carbon (AWSC) nanofiltration membranes to reject heavy metal ions. Characterization techniques for Fe₃O₄@AWSC nanoparticle (NP) included FT-IR, DLS-ZP, XRD, SEM, EDS mapping, BET, and VSM analyses. Also, SEM, EDS mapping, XRD, AFM, Zeta potential, and water contact angle investigations were utilized to characterize the synthesized membranes. The modified membranes' hydrophilicity and porosity were observed to have improved. To affirm the presence of mesoporous Fe₃O₄@AWSC in the membrane matrix, EDS mapping, SEM, and AFM studies were used. It was also confirmed how the membrane's characteristics and performance were influenced by the existence of mesoporous Fe₃O₄@AWSC. The mixed matrix membrane made of a 0.5 wt% mesoporous Fe₃O₄@AWSC demonstrated a high pure water flow of 72.19 L/m² h, a flux recovery ratio of 71.66%, and a desired rejection of over 98% against Cu²⁺, Pb²⁺, and Zn²⁺. The 0.5 wt% NP membrane had a noticeably improved surface hydrophilicity, which promoted successful antifouling performance. The results demonstrate that a mixed-matrix antifouling Fe₃O₄@AWSC membrane is highly effective in eliminating heavy metal ions.