Eco-engineered bio-imprinted polymer for selective aluminum sequestration in wastewater

Aluminum (Al) poisoning in wastewater poses a significant environmental and public health threat, with potential association to neurological diseases such as Alzheimer’s. Conventional remediation methods often rely on synthetic materials with environmental drawbacks. This study presents a sustainable alternative by synthesizing ion-imprinted polymers (IIPs) from chia seed extract, a biobased resource rich in functional groups. Using Al (III) ions as a template and epichlorohydrin as a crosslinker, IIPs with specific sites for capturing aluminum. These IIPs demonstrated performance superior to non-imprinted polymers (NIPs), achieving a maximum adsorption capacity of 188.7 mg/g and a removal efficiency of 96.02%. Optimal conditions were found to be a pH of 5.5, a temperature of 30 °C, and a 30-minute contact time. Statistical analysis through ANOVA confirmed the significance of the findings (p < 0.001). The adsorption process conformed to the Langmuir, Freundlich, Temkin, and Sips isotherm models, as well as the pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich kinetic models, suggesting a monolayer, endothermic, and spontaneous characteristic. The IIPs also proved highly reusable, maintaining their effectiveness over 10 regeneration cycles. These results demonstrate that chia seed-based IIPs provide a biobased, selective, and reusable approach for aluminium removal from wastewater, offering a balance between sustainability and adsorption efficiency.