H. Khazaal, S. Optimization and Adsorption Modeling of Lead Ions (II) on Carbonaceous Materials: Comparative Evaluation of Raw and Citric Acid-Modified Commercial Activated Carbon and Tea Waste Derived Biochar. IJCPE 2026, 27 (1), 127-142. https://doi.org/10.31699/IJCPE.2026.1.11.