A structurally engineered flower shaped magnetic hierarchical sorbent for rapid and selective uptake of Pb2+ ions from water samples†

Abstract

Considering the noxious effects of Pb²⁺ ions on living organisms as well as the environment, we focus our attention to achieve rapid and selective uptake of Pb²⁺ ions from aqueous solutions. In this direction, our current work describes an efficient synthetic protocol for the development of economically viable, three-dimensional (3D) ferrite-based hierarchical structures to eradicate Pb²⁺ ions from wastewater. These magnetic architectures exhibited high BET surface area of 39.5312 m² g⁻¹, good thermal stability up to 400 °C and flower shaped morphology. The synthesized iron oxide-based materials were systematically characterized through XRD, SEM, VSM, TEM, FT-IR, EDS, XPS, and ED-XRF to elucidate their physio-chemical properties. The designed SALDETA@CPTMS@Fe₃O₄ adsorbent displayed excellent performance, faster kinetics, rapid separation, high selectivity, and good recyclability for the sorption of Pb²⁺ ions. Adsorption equilibrium results were justified by the Langmuir model, which indicated the maximum adsorption capacity of 415.5 mg g⁻¹ and conformed to pseudo second order kinetics. Sorption investigations disclosed that the functionalities available on the surface of the developed sorbent and its hierarchical structure played an active role in the uptake of metal ions and readily removed (within 8 min) Pb²⁺ ions from solution. Different variables such as pH, amount of sorbent, contact time, eluting agent, effect of interfering ions, etc. were optimized to achieve the best results. This 3D magnetic adsorbent was successfully employed for the elimination of Pb²⁺ ions in real water samples with good selectivity and efficiency. Furthermore, experimental exploration also indicated that the fabricated material could be advantageous for industrial applications due to its high stability, good regeneration ability (5 runs) and fast sorption-desorption cycle.