Composite of\nHydrolyzed PAN and β‑Cyclodextrin\nForms a Nanofiber Membrane with an Excellent Removal Effect on Various\nCationic Dyes and Copper Ions

The presence of dyes and heavy metals in wastewater represents\na significant environmental and public health hazard, necessitating\nthe development of efficient materials for their removal. In this\nstudy, we modified hydrolyzed polyacrylonitrile (PAN-H) and combined\nit with β-cyclodextrin (β-CD) by using an electrostatic\nspinning technique to fabricate composite nanofibrous membranes for\nwater treatment applications. The resulting PAN-H/β-CD nanofiber\nmembranes exhibit spindle-shaped fibers and porous structures with\na high density of charged functional groups, which significantly enhance\ntheir selective adsorption capacity compared to pure PAN fibers. Furthermore,\npost-treatment with a sodium bicarbonate solution further improved\nthis capacity, resulting in the membranes demonstrating a remarkable\nadsorption efficiency for cationic dyes. The adsorption process conformed\nto the Langmuir and pseudo-second-order kinetic models, with maximum\nadsorption capacities of 216.94 mg/g for methylene blue (MB), 471.59\nmg/g for malachite green (MG), 299 mg/g for crystal violet (CV), and\n43.95 mg/g for copper ions. The selective adsorption of these positively\ncharged contaminants, particularly cationic dyes and metallic copper,\nindicates that PAN-H/β-CD membranes have significant potential\nfor the treatment of wastewater containing similar pollutants.