Removal of methylene blue with nanomagnetic coated wild chestnut shells: thermodynamic, kinetic, isotherm, and mechanism studies

Abstract

Adsorption is one of the important methods used to remove dyestuff (methylene blue) from industrial wastewaters with suitable adsorbents. In this study, magnetic wild chestnut shell coated Fe3O4 was used as the adsorbent. The magnetic wild chestnut shell coated Fe3O4 nanoparticles were synthesized using the chemical precipitation method. The surface properties of the adsorbents were characterized by using spectroscopic techniques such as scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller, and Fourier transform infrared spectroscopy. The effect of adsorption parameters such as initial pH (2-9) value, adsorbent dosage (0.1-0.5 g), temperature (298-318 K), contact time (0-240 min), and initial concentration (25-150 mg L-1) were researched. The experimental data indicated that the adsorption isotherms were well described by the Langmuir equilibrium isotherm equation and the calculated adsorption capacities of the magnetic wild chestnut shell coated with Fe3O4 were 140.84 mg g(-1). The adsorption of methylene blue was determined as in compliance with the pseudo-second-order kinetic model. The thermodynamic parameters calculated to estimate the nature of adsorption indicated spontaneous and endothermic adsorption (Delta H degrees = 69.00 kJ mol(-1)). The adsorption/desorption circulation test showed good reusability performance up to the fourth cycle. Furthermore, considering all the results, the advantage of being produced from a cheap source, high adsorption capacity, and rapid procurement feasibility has led to a great promise for the removal of methylene blue from aqueous solutions.