Study on Wastewater Treatment in the Textile Industry by Adsorption of Reactive Red 141 Dye Using a Phosphogypsum/Vanadium Composite Developed from Phosphate Industry Waste

A novel method has been explored based on the recovery of two industrial wastes V2O5 and phosphogypsum from the fertilizer production industry, which also provide a significant challenge due to their toxicity and environmental impact. To solve the problem of these two harmful wastes, these residues have been transformed into valuable resources, by the elaboration of Nanoparticles vanadate-hydroxyapatite (NPs-HAP/VAP) adsorbent, contributing a sustainable solution without requiring expensive or highly skilled work. This comprehensive investigation explores the adsorption of the reactive red 141 dye (RR 141) on Ca10(VO4) x(PO4)6−x(OH)2, with (xi = 0, 1.5, 3, 4.5, and 6). Using a Centered Composite Design (CCD), several parameters influencing the adsorption process were examined. The optimal adsorption capacity is 50 mg. g-1 under optimal conditions 57.5 mg of the adsorbent dose, 152.5 mgL-1 for the RR 141, pH 8, 92.5 minutes of contact time, and incorporation ratio of 4.5 with an R2 of 0.99. These results reinforce the effectiveness of our chosen CCD model. Kinetic analysis demonstrated a pseudo-order reaction model with an R2˃0.92, while the Sips isotherm describes the adsorption process. Thermodynamic studies revealed spontaneous adsorption, suggesting a physical character enhanced by a positive entropy variation.