<p>Adsorption is one of the most widely methods due to inexpensive and eco-friendly nature. In this context a novel composite was produced through in situ chemical polymerization of aniline on the surfaces of NaPO₃-Fe₂O₃ particles. The analytical techniques such as Fourier transform infrared spectroscopy, X-ray diffraction, BET and Scanning Electron Microscopy were used to analyze the structure of the investigated material. The BET analysis revealed that polyaniline@NaPO₃-Fe₂O₃ exhibited a specific surface area of 16.17 m²/g and contained a pore volume measuring of 0.069 m³/g. FTIR analysis revealed characteristic bands of both polyaniline and NaPO₃-Fe₂O₃, confirming the successful polymerization of polyaniline on the NaPO₃-Fe₂O₃ surface. The experimental results demonstrated a remarkable performance in removing Orange G from aqueous medium, achieving an optimal removal efficiency of 94.39%. This result was obtained after 25&#xa0;min of agitation under precisely controlled conditions: a solution pH maintained at 5.45, adsorbent dose fixed at 0.5&#xa0;g·L⁻¹ and an initial OG concentration of 20&#xa0;ppm. Equilibrium isotherm modeling revealed that the adsorption of OG dye on the polyaniline@NaPO₃-Fe₂O₃ adsorbents was well fitted with Langmuir model, showing a maximum adsorption capacity of 126&#xa0;mg/g. The adsorption kinetics of the system were effectively described by a pseudo-second-order model in comparison to other kinetic models. The process of OG being adsorbed onto polyaniline@NaPO₃-Fe₂O₃ occurs spontaneously through an endothermic reaction. Demonstrating that the prepared composite has a high outstanding adsorption property. The main adsorption mechanisms facilitating the removal of this azo dye by polyaniline@NaPO₃-Fe₂O₃ include π—π interactions, hydrogen bonding, and electrostatic attraction.</p>