Evaluation of the efficiency of magnetized clinoptilolite zeolite with Fe₃O₄ nanoparticles on the removal of basic violet 16 (BV16) dye from aqueous solutions

Abstract

Treatment of colored wastewater is one of the important challenges of environmental engineers. Adsorption is one of the most efficient methods in dye removal. The aim of this study was to prepare a magnetic adsorbent with Fe3O4 nanoparticles as an inexpensive adsorbent to remove basic violet 16 (BV16) dye from aqueous media. In this experimental study, the effect of parameters such as initial solution pH, adsorbent dose, initial dye concentration, and contact time on the adsorption rate was investigated. The residual dye concentration was read at 545 nm by using a spectrophotometer. Physical, surface, and magnetic properties of the adsorbent were analyzed using Brunauer–Emmett–Teller (BET), Vibrating-Sample Magnetometer (VSM), X-ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning electron microscope (SEM) techniques. Adsorption data were described by Langmuir and Freundlich isotherms and reaction kinetics. The results showed that with increasing the contact time and increasing the adsorbent dose, the amount of dye removal by the adsorbent increased and with decreasing the initial concentration of dye, the amount of removal increased. The results also showed that with increasing pH, the removal efficiency of the process increased linearly. According to resuls, the highest BV16 dye adsorption efficiency was 99%, which was obtained at determined values of studied parameters including pH of 7, adsorbent dose: of 0.5 g/L, initial BV16 dye concentration of 25 mg/l, mixing speed of 250 rpm, and contact time of 45 min. Moreover, according to results, removal of BV16 dye using adsorption onto clinoptilolite zeolite magnetized with Fe3O4 nanoparticles obey a second-order kinetic model and Freundlich model (R2>0.99). According to SEM images, the adsorbent surface used is non-uniform and has many pores and also the morphology of the adsorbent surface is preserved after loading of Fe3O4 nanoparticles. According to VSM images, the magnetic saturation in composite is 18.11 emu/g. Results hihlighted the adsorption of BV16 dye onto clinoptilolite zeolite magnetized with Fe3O4 nanoparticles was a useful technique and could provide high efficiency in removal of studied dye from aqueous solutionsl; thus, it mabe be effective and useful in removal other similar pollutants.