Comparison of adsorption capacities of Ni (II) ions from aqueous solutions with raw potato peel and processed potato peel using waste potato peels. Isotherm, kinetic and thermodynamic studies

This thesis aims to investigate the promising application of waste potato peels (PP) and processed potato peels (MPP) as a suitable solution for effectively removing Ni(II) ions from aqueous solutions. For PP, the best working conditions for removing Ni(II) ions from aqueous solutions were determined as an initial concentration of 500 mg/L, an adsorbent dosage of 0.3 g, a contact time of 100 min, and a solution pH of 6.21. For MPP, the best working conditions were determined as an initial concentration of 500 mg/L, an adsorbent dosage of 0.15 g, a contact time of 100 min, and a solution pH of 6.21. In order to better understand the removal capacities of adsorbents, studies were conducted at different temperatures. Adsorption capacities of Ni(II) ions were determined as 25.125, 29.325, and 33.112 mg/g for PP at different temperatures (298 K, 308 K, and 318 K), respectively. Adsorption capacities for MPP under the same conditions were found to be 68.965, 78.125, and 85.470, respectively. Further analysis of adsorption kinetics showed that experimental data for both PP and MPP adsorbents fit the pseudo-second-order model. Thermodynamic studies revealed that the adsorption process related to Ni(II) metal ions on the used adsorbents was endothermic and spontaneous. As a result, PP and MPP were determined to be highly efficient and environmentally friendly adsorbents for the removal of Ni(II) ions from aqueous media. Their very good adsorption capacity in effectively removing metal ions, combined with their simple accessibility, cost-effectiveness, and origin as agricultural waste, positions them as promising adsorbents for sustainable applications in water treatment and environmental remediation.