Heterogeneous Fenton-like Decolorization of Methyl Violet 2B Using Magnetic Zeolite Supported Guar Gum: Kinetics and Thermodynamics

In this study, an environmentally friendly and novel magnetic catalyst was prepared using guar gum and zeolite, and coded as m-GG-Zeo. It was synthesized by chemical precipitation method and characterized using various techniques including scanning electron microscopy with energy dispersive spectroscopy (SEM–EDS), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and Zeta potential analysis. The efficiency of m-GG-Zeo in decolorizing methyl violet 2B (MV-2B) through Fenton-like oxidation was investigated. Parameters such as pH, hydrogen peroxide concentration, catalyst amount, initial dye concentration, temperature, NaCl and Na₂SO₄ concentration were examined. Furthermore, both kinetic and thermodynamic analyses were conducted. The experimental findings demonstrated that under optimized conditions—including 1 g/L of m-GG-Zeo amount, an initial MV-2B concentration of 20 mg/L, pH 6, 20 °C, 0.0236 M H₂O₂ concentration, and a reaction time of 10-min—MV-2B decolorization efficiency reached 85.1%. Kinetic and thermodynamic assessments indicated that diffusion-controlled process with an endothermic nature and non-spontaneous behavior under the studied conditions.