Abstract
Abstract This research focuses on the elimination of copper and lead ions from water using zirconium phosphate as an adsorbent. Building upon previous work focused on adsorption isotherms and kinetic models, the adsorption behavior was evaluated using models done by (Lang, Freu, Tem, and Dub–Radus). The findings indicated that the Freu model was the most precise in representing copper ion adsorption, suggesting that the adsorption occurs on a heterogeneous surface (R² = 0.984). In contrast, the Langmuir model provided the best description for the adsorption of lead ions, aligning with the concept of monolayer adsorption on a uniform surface (R² = 0.923). Kinetic studies indicated that intra-particle diffusion played a crucial role in the adsorption process. The findings showed that the process was endothermic and spontaneous. The positive ΔS° value implies an increase in disorder at the solid liquid interface. Overall, zirconium phosphate displayed significant potential as an effective adsorbent for the removal of Pb(II) and Cu(II) ions from water, providing useful information for enhancing adsorption-based water treatment systems.