Raw potato peel as a biosorbent for lead(II) and dye removal: adsorption behavior, kinetics, and thermodynamic analysis
摘要
This study investigated the potential application of raw potato peels (RPP) for the effective removal of Pb2+ and methylene blue (MB) ions from aqueous solutions. The optimal conditions for Pb2+ removal were determined to be an initial concentration of 800 mg/L, an adsorbent dose of 0.2 g, a contact time of 100 min, and a pH of 6.07. The most favorable conditions for the adsorption process of methylene blue (MB) were found to include an initial concentration of 400 mg/L, a 0.2 g adsorbent amount, a contact duration of 100 min, and a solution pH adjusted to 6.09. The optimal operating conditions for RPP were determined using 25-mL solutions. Pb2+ ion removal capacities in RPP were determined to be 78.74, 92.59, and 104.16 mg/g at varying temperatures of 298 K, 308 K, and 318 K, respectively. Under the same conditions, MB uptake was recorded as 67.56, 75.75, and 90.09 mg/g. Further examination into the adsorption kinetics indicated that the experimental data were consistent with the pseudo-second order model for RPP. Thermodynamic analysis demonstrated that the adsorption of Pb2+ and methylene blue (MB) onto the raw potato peel was spontaneous, as indicated by negative Gibbs free energy (ΔGo) values, and endothermic in nature, supported by positive enthalpy change (ΔHo), suggesting increased adsorption capacity at higher temperatures.Overall, the results suggest that raw potato peel (RPP) is a highly effective and environmentally benign adsorbent for the removal of Pb2+ and methylene blue (MB) from aqueous media.