A novel and biocompatible Fe3O4 loaded chitosan polyelectrolyte nanoparticles for the removal of Cd2+ ion

Abstract

In this work, Fe₃O₄ loaded chitosan (CS) nanoparticles (NPs) and microparticles (MPs) were synthesized based on ionic gelation technology for the removal of Cd²⁺ ion. The influencing parameters including initial concentration, pH, contact time and recycling was evaluated and optimized. The results showed that particle size of Fe₃O₄ loaded CS NPs and MPs was in the range of 164.05-768.69 nm, and the former showed relatively higher adsorption capacities (97.86 mg/g) on Cd²⁺ ion than the latter after 90 min at pH 5.0 for the solutions with initial Cd²⁺ ion of 100 mg/L, respectively. Brunauer, Emmett and Teller (BET) test illustrated 61.48 m²/g of specific surface area, 0.0274 cm³/g of pore volume and 6.03 nm average pore size. The results of FT-IR, TEM, EDS and XRD indicated that Fe₃O₄ was well incorporated into CS NPs and MPs. Moreover, the adsorption equilibrium data fitted well with Langmuir isotherm model and adsorption process followed the pseudo-second-order model. The adsorption mechanisms could be well explained though coordination and electrostatic attraction. Findings of this work highlighted the potential using Fe₃O₄ loaded CS NPs as an effective and recyclable adsorbent for the removal of heavy metal ions in industrial wastewater treatment.

Keywords: Chitosan; Fe(3)O(4); Heavy metal adsorbent; Mechanisms; Polyelectrolyte nanoparticles.