Removal of Alizarin yellow GG from aqueous solutions using magnetic biochar derived from Persea americana: adsorption...

Wastewater treatment has become an important environmental concern due to the increasing accumulation of hazardous contaminants in aquatic environments. In this study, Persea americana (PA) seeds were utilized as a precursor for the production of magnetic biochar (mbPA) through pyrolysis at 450 °C, followed by iron modification. The prepared material was applied for the removal of anionic Alizarin Yellow GG (AYGG) from aqueous solutions. Its physicochemical characteristics were investigated using FT-IR, XRD, SEM-EDS, BET, zeta potential, and particle size analyses. The effects of main experimental parameters, including pH, contact time, adsorbent dosage, initial dye concentration, and temperature, were systematically examined. The adsorption data were found to fit the Langmuir isotherm model, with a maximum adsorption capacity of 5.35 mg g^-1. Kinetic results showed that the process followed a pseudo-second-order model. Thermodynamic analysis indicated that the adsorption process was spontaneous (ΔG = -2.61 to -6.19 kJ mol^-1) and endothermic. Furthermore, the experimental data were modeled using an artificial neural network (ANN), and the 5-7-1 structure yielded the most accurate predictions (R² = 0.9758, MSE = 0.00173). Overall, the results indicate that mbPA can be considered a potential adsorbent for the removal of AYGG from aqueous media.