Fabrication of a Recyclable Sodium Alginate‐Zeolite/Glutaraldehyde ( <scp>SA</scp> ‐ <scp>HZ</scp> / <scp>GA</scp> ) Composite Adsorption Membrane and Its Efficient Removal of Cu( <scp>II</scp> )

ABSTRACT Cu(II) contamination in industrial wastewater constitutes a major challenge to global environmental management as traditional treatment methods are plagued by high energy consumption, secondary pollution risks, and substantial costs. A technical strategy was developed to prepare glutaraldehyde‐crosslinked sodium alginate‐zeolite (SA‐HZ/GA) composite adsorption membranes via phase inversion. This approach leverages zeolites' structural reinforcement and mass transfer channel formation combined with glutaraldehyde's crosslinking properties to optimize material performance. SA‐HZ/GA features abundant mesopores with sizes ranging from 2 to 16 nm and exhibits fracture strength over 74% higher than pure sodium alginate membranes. At pH 5 and 25°C, its Cu(II) adsorption capacity reaches 46.80 mg/g with over 80% removal efficiency maintained after 5 cycles with 0.1 M HCl as desorbent. The adsorption process fits the Langmuir model ( R 2 = 0.999) and follows pseudo‐second‐order kinetics, indicating monolayer chemical adsorption. Thermodynamic analysis revealed that the adsorption was spontaneous (Δ G = −12.5 kJ/mol) and endothermic (Δ H = 28.4 kJ/mol), with a positive entropy change (Δ S = 0.14 kJ/(mol·K)) suggesting increased randomness at the solid–liquid interface. This work provides an efficient, stable, and cost‐effective engineering solution for heavy metal‐laden wastewater treatment.