Synthesis of Magnetic Iron Oxide Heat-Activated Termite Mound Composite for Adsorption of Basic Blue 41 Dye from Textile Wastewater: Characterization and Box–Behnken Optimization

The discharge of textile effluents containing dyes poses severe environmental risks. This study aimed to develop a magnetic iron oxide–HTM (magnetite–heat-activated termite mound) composite via the coprecipitation method for the adsorption of Basic Blue 41 (BB41) dye from textile wastewater under batch conditions. The magnetic iron oxide–HTM composite was characterized using BET (surface area), XRD (crystalline structure), FTIR (functional groups), and SEM (microstructure) analyses, confirming the successful synthesis of magnetic iron oxide–HTM. Comprising 80% HTM by mass, the composite demonstrates economic viability. Using batch experiments and a Box–Behnken design, the adsorption performance of magnetic iron oxide–HTM for BB41 dye removal from aqueous solutions was evaluated. Optimization of the sorption process revealed that a dosage of 2.6 g/L, a contact time of 47.5 min, a temperature of 60 °C, and an initial dye concentration of 100 mg/L resulted in a BB41 dye removal efficiency of 98%. Additionally, magnetic–HTM effectively removed BB41 dye from real wastewater samples, achieving a removal efficiency exceeding 80%, highlighting the improved sorption properties of the modified termite mound. The spent magnetic–HTM was easily separated from the treated solution using an external magnet and successfully recovered. Its reusability demonstrated a dye removal efficiency of 78% after four cycles, without compromising its magnetic properties. Overall, the magnetically separable magnetic iron oxide–HTM composite shows significant potential for the treatment of textile wastewater.