Synthesis of Fe3O4/polyaniline nanocomposite and its application for nitrate removal from aqueous solutions

The aim of this work was to investigate the sorption characteristics of Fe3O4 coated on polyaniline (Fe3O4/PAn) for the removal of NO3− ions from aqueous solutions. The sorption of NO3− ions by the batch method was carried out. The optimum conditions of sorption were found to be a Fe3O4/PAn dose of 0.4 g in 100 mL of NO3− solution, a contact time of 10 min, pH and temperature 7 and 40°C, respectively. Temperature had a negative effect on the removal efficiency. Three equations, i.e., Morris–Weber, Lagergren, and pseudo-second-order, were tested to track the kinetics of the removal process. The Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models were subjected to sorption data in order to estimate sorption capacity, intensity, and energy. The thermodynamic parameters ΔH, ΔS, and ΔG were evaluated. They showed that the adsorption of NO3− onto Fe3O4/PAn was feasible, spontaneous, and exothermic under the studied conditions. It can be concluded that Fe3O4/PAn has potential to remove NO3− ions from aqueous solutions at different concentrations. The system Fe3O4/Pan was successfully tested for a high removal efficiency of NO3− from urban wastewater. J. VINYL ADDIT. TECHNOL., 19:147–156, 2013. © 2013 Society of Plastics Engineers