An efficient removal of methylene blue and lead(II) from aqueous solutions by green synthesized iron oxide/pillared bentonite nanocomposite

Abstract

We have reported a facile, low-cost, and environmentally friendly procedure to eliminate toxic ions of lead(II) and organic dye of methylene blue (MB) by green synthesized Fe3O4 magnetic nanoparticles (MNPs) on the pillared bentonite (Al–B) utilizing Cordia myxa leaf extract. The synthesized Fe3O4@Al–B nanocomposite was characterized using different techniques. The Field Emission Scanning Electron Microscope showed that the Fe3O4 MNPs were successfully produced by the green route and homogeneously dispersed on the surface of bentonite. The green synthesized magnetic nanocomposite obtained an average surface area of 117.53 m2/g with a saturation magnetization of 27/1 emu/g. The high Brunauer–Emmett–Teller (BET) specific surface area confirmed its potential application in the separation of pollutants such as dyes and toxic metals from the environment. Hence, the removal efficiency of the synthesized Fe3O4@Al–B nanocomposite was examined in the removal of lead(II) and MB from aqueous media. In the optimization step, the effects of the pH, the dosage of the nanocomposite, and initial adsorbate concentration were also studied in the adsorption processes. The fitted experimental data to kinetic isotherms clarified that the adsorption process, for both adsorbates, obeyed the pseudo-second-order kinetic model. The resulted data showed that as-synthesized Fe3O4@Al–B nanocomposite operates as an effective adsorbent in the removal of lead(II) and MB from aqueous media with good recycle-ability several times.