Chitosan immobilization and Fe₃O₄ functionalization of olive pomace: An eco-friendly and recyclable Pb²⁺ biosorbent

An effective and sustainable biosorbent (MagOPIC) was prepared from chitosan and olive pomace by the combined action of immobilization and magnetic modification to remediate Pb²⁺-contaminated waters. Pb²⁺ sorption yield at the end of the equilibrium (45 min) period was estimated to be 98.56 ± 0.28% at pH 5.5. Agitation speed, ionic strength, and temperature did not significantly affect the Pb²⁺ biosorption. Biosorption kinetics are successfully fitted by the pseudo-second-order equation while the equilibrium biosorption data are properly modeled using the Freundlich and D-R isotherms. MagOPIC has also exhibited a high biosorption yield in the column tests (≥99%) and showed remarkable stability up to twenty consecutive regeneration cycles. Furthermore, it was successfully used for the treatment of Pb²⁺ containing real wastewater. The findings of this work highlighted the potential use of MagOPIC as a novel, cost-effective and eco-friendly biosorbent for the Pb²⁺ removal from the contaminated aquatic phase.