Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE A recyclable sodium alginate-zeolite/glutaraldehyde (SA-HZ/GA) composite adsorption membrane is fabricated via phase inversion. Synergistic crosslinking and zeolite reinforcement result in high mechanical strength, excellent Cu(II) adsorption capacity (46.80 mg/g), and outstanding reusability over 5 cycles, offering a promising and sustainable solution for heavy metal wastewater treatment.

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 (ΔG = −12.5 kJ/mol) and endothermic (ΔH = 28.4 kJ/mol), with a positive entropy change (ΔS = 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.