Highly effective Pb(II) adsorption using physical–chemical double crosslinked polyvinyl alcohol-coated nano-calcium carbonate aerogel beads

Several issues plague polymer and calcium carbonate (CaCO 3 ) composites, including the tendency of CaCO 3 particles to aggregate and detach easily, as well as a limited number of adsorption sites. To address the aforementioned issues, a novel large-particle hollow shell-structured PVA-encapsulated nano-CaCO 3 aerogel (PCC) was prepared. The characterization results indicate that the PCC (∼3 mm) possess a three-dimensional network structure with a stereoscopic arrangement of big and small pores. The adsorption of Pb(II) adheres to pseudo-first-order adsorption kinetics and the adsorption equilibrium follows the Langmuir model with a maximum adsorption capacity of 482.85 mg/g at 313 K for Pb(II). The PCC exhibits good selectivity and stability of adsorption towards Pb(II), retaining 92.6 % of its initial adsorption capacity after seven cycles. The large-particle morphology of this material demonstrates significant potential for effectively removing Pb(II) in wastewater treatment applications.