Efficient removal of arsenic(III) from aqueous media using magnetic polyaniline-doped strontium–titanium nanocomposite

Abstract

In this study, a novel nanocomposite adsorbent based on magnetic polyaniline and strontium–titanium (MP-SrTiO₃) nanoparticles was synthesized via a simple and low-cost polymerization method for efficiently removing of arsenic(III) ions from aqueous samples. The chemical structure, surface properties, and morphology of the prepared adsorbent were studied using Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The main effective parameters on the removal efficiency, such as pH, adsorbent dosage, salt, and contact time, were studied and optimized. The validity of the proposed method was checked by adsorption isotherm and kinetics models. Consequently, the adsorption kinetics corresponded to the first order (R² > 0.99), and the experimental equilibrium fitted the Langmuir model with a maximum monolayer adsorption capacity of 67.11 mg/g (R² > 0.99) for arsenic(III) ions. Corresponding to thermodynamic Vant's Hof model (ΔG° (kJ/mol), ΔH° (kJ/mol), and ΔS° (kJ/mol K) − 8.19, − 60.61, and − 0.17, respectively), the mechanism and adsorption nature were investigated with that suggested exothermic and physisorption mechanism.