The development of sustainable hydrogel-based materials for water treatment has gained increasing attention due to their tunable structure and adsorption capabilities. In this work, methacrylate-alginate hydrogels were synthesized via a green photopolymerization route under UV radiation, to remove toxic metal ions from aqueous media. A 2² full factorial design was employed to investigate the effects of alginate concentration (20–30 g L?¹) and UV exposure time (1–3 h) on swelling behavior and adsorption performance. FTIR analysis confirmed successful functionalization of alginate with glycidyl methacrylate and the formation of crosslinked networks after photopolymerization, as evidenced by characteristic bands corresponding to hydroxyl, carboxylate, and ester groups. SEM images revealed highly porous three-dimensional structures with interconnected pores, with pore sizes ranging from 20 to 110 ?m. Higher alginate concentrations and longer UV exposure times resulted in denser structures with smaller pores, indicating increased crosslinking density. Water uptake varied from 135 to 442%, with higher swelling observed at lower alginate concentrations due to reduced network density. In multicomponent adsorption tests (Cu²?, Cd²?, Ni²?, Zn²?, Mn²?, and Cr??), the hydrogels exhibited strong selectivity toward divalent cations, particularly Cu²?. The best-performing formulation (alginate 30 g L?¹, UV exposure time of 3 h) achieved Cu²? removal up to ~100% at low concentration (0.3 mmol L?¹) and maintained significant efficiency at higher concentrations, following the affinity order: Cu²? > Zn²? > Cd²? > Ni²? > Mn²? >> Cr??. Adsorption performance was strongly influenced by pH, with maximum removal observed at pH 5 due to deprotonation of carboxyl groups and enhanced electrostatic interactions. Kinetic data were best described by the pseudo-second order model, indicating the contribution of chemisorption mechanisms, while equilibrium data fitted well to the Langmuir isotherm, with a maximum Cu²? adsorption capacity of 0.593 mmol g?¹. Overall, the results demonstrate that photopolymerized methacrylated alginate hydrogels are efficient, selective, and sustainable adsorbents for metal ion removal, highlighting their potential for environmental remediation applications.
Comissão Organizadora
Pedro Alves da Silva Autreto
Comissão Científica
Ferramenta completa de submissão, avaliação e publicação de anais para eventos científicos.
