Use of low-cost processed orange peel for effective removal of cobalt (II) and manganese (II) from aqueous solutions

This study aims to explore the promising application of processed orange peel waste (POP) as a viable solution for effectively eliminating Mn(II) and Co(II) ions from water-based solutions. Co(II) ions were found to work best under the following conditions: 250 mg/L of starting concentration, 0.2 g of adsorbent dosage, 100 min of contact duration, and a solution pH of 6.05. Through meticulous experimentation, the optimal conditions for dealing with Mn(II) ions were identified, encompassing a starting concentration of 200 mg/L, 0.2 g as the adsorbent dose, 100 min of contact time, and maintaining a solution pH of 5.42. To delve deeper into surface characteristics of POP, the adsorption capabilities of Co(II) and Mn(II) ions were assessed at various temperatures (298 K, 308 K, and 318 K), revealing promising results: Co(II) displayed adsorption capacities of 21.432 mg/g, 23.364 mg/g, and 25.906 mg/g, while Mn(II) exhibited capacities of 20.366 mg/g, 22.123 mg/g, and 25.252 mg/g. Further analysis of the adsorption kinetics pointed to the pseudo-second-order model as the most accurate representation of the experimental data for both Co(II) and Mn(II) ions. Thermodynamic investigations have provided compelling evidence, affirming the endothermic and spontaneous essence of the adsorption process concerning these noble metal ions on POP. As a result, POP exhibited an exceptionally efficient and environmentally benevolent substitute material for the extraction of Co(II) and Mn(II) ions from aqueous media. Its innate ability to embrace these ions with efficacy highlights its intrinsic prowess in harmonizing with the environment, making it a true paragon of sustainable engineering. Its remarkable adsorption capacity, coupled with simple accessibility, cost-effectiveness, and its origin as an agricultural waste, positions it as a promising candidate for sustainable applications in water purification and environmental remediation.

Automated summary

This study explores the application of processed orange peel waste (POP) as an effective solution for removing Mn(II) and Co(II) ions from water. The optimal conditions for removing these ions were determined, and the adsorption capacities of POP at different temperatures were evaluated. Thermodynamic investigations confirmed the nature of the adsorption process. Thus, POP is an efficient and environmentally friendly material for water purification and environmental remediation.