Oxygen-rich poly-bisvanillonitrile embedded amorphous zirconium oxide nanoparticles as reusable and porous adsorbent for removal of arsenic species from water

Highlights: • Novel synthesis of ZrO₂ nanoparticles encapsulated in poly-bisvanillonitrile structure. • Highly porous and O-rich hybrid structure provides routes for metalloid interaction. • Excellent capacities and kinetics for As(III) and As(V) removal from solution. • Stable and regenerable adsorbent to remediate pollution sustainably. A new oxygen-rich porous polymer based on bisvanillonitrile was synthesized and characterized. This polymer was employed as support for the anchoring of 14.5 w% amorphous zirconium oxide nanoparticles. The formation of homogeneously dispersed nanoparticles in the poly-bisvanillonitrile (PBVN) host material was confirmed using N₂-sorption, XRPD, XPS and electron microscopy. The combination of zirconium oxide nanoparticles having active adsorption sites with the porous supporting material showed excellent adsorption of arsenic species. The resulting adsorption capacities of the hybrid material extend to 245 mg g⁻¹ for arsenite (As^III) and 115 mg g⁻¹ for arsenate (As^V). Moreover, adsorption kinetics showed a fast removal of both arsenic species with initial adsorption rate h of 0.0646 mg g⁻¹ min⁻¹ for arsenite and 0.0746 mg g⁻¹ min⁻¹ for arsenate. The immobilization was not interfered by the presence of other compounds in solution, indicating the applicability in real working environments. The material could be regenerated in a continuous mode using a 0.1 mol L⁻¹ sodium hydroxide solution at 70 °C to desorb arsenic.