Chitosan　(CS)　is　widely　used　in　the　treatment　of　wastewater　containing　metal　ions.　However,　the　poor　stability　in　acidic　aqueous　solutions　severely　limits　its　application　in　many　practical　scenarios.　In　this　work,　a　CS-based　composite　nanofiber　membrane　was　prepared　by　electrospinning　using　urushiol,　a　natural　biomaterial,　as　the　cross-linking　agent.　The　application　of　the　CS-urushiol　(CS-U)　membrane　in　the　adsorption　and　recovery　of　Cr(VI)　in　wastewater　was　systematically　studied.　The　CS-U　membrane　showed　great　resistance　to　strongly　acidic　and　oxidative　environments,　and　the　adsorption　process　combined　two　mechanisms　of　electrostatic　attraction　and　redox　reaction.　Due　to　the　nanoscale　fibers,　porous　structure,　and　strong　acid　resistance,　the　CS-U　membrane　adsorbed　Cr(VI)　rapidly　and　efficiently　in　both　batch　and　continuous　modes.　Moreover,　the　adsorption　capacity　and　selectivity　of　the　CSU　membrane　for　Cr(VI)　could　be　maximized　simultaneously　by　adjusting　the　solution　pH,　promoting　the　recovery　of　high-purity　Cr2O3　©　2023　the　author(s),