Functional Conversion From Waste Tire To Drug Removal: Isotherm, Thermodynamıc And Kinetıc Analysıs Of Sunitinib Removal

Abstract

This comprehensive study focused on producing activated carbon from waste tires via pyrolysis and chemical activation and subsequently investigated its potential for removing the cytotoxic cancer drug Sunitinib from aqueous solutions. The physicochemical properties of the synthesized activated carbon, including surface morphology, pore structure, and surface chemistry, were meticulously characterized using SEM, BET, and pHpzc analyses, respectively. The effects of critical operational parameters—adsorbent dose, solution pH, initial concentration, and contact time—on adsorption efficiency were systematically investigated. Optimal conditions were successfully determined as 40 mg/50 mL adsorbent dose, neutral pH, 50 mg/L initial concentration, and 150 min contact time. Kinetic analysis revealed that the adsorption mechanism followed the pseudo-second-order model, with chemisorption being the dominant rate-limiting step. Equilibrium data showed excellent agreement with the Langmuir isotherm model, indicating a calculated maximum adsorption capacity of 65.63 mg/g. Thermodynamic evaluation confirmed that the process was spontaneous (ΔG°