Utilization of Chemically Modified Banana Peels as an Eco-Friendly, Cost-Effective and Sustainable Biosorbent for the Efficient Removal of Copper and Manganese from Aqueous Media: A Comparative Analysis

Herein, the adsorption of Cu 2+ and Mn 2+ from individual aqueous solutions was investigated using raw banana peels (BP) and H 2 SO 4 -modified banana peels (mBP–SA) as a low-cost biosorbent prepared from renewable agricultural waste. Through a batch of adsorption experiments, extent to which adsorption efficiency is influenced by pH, exposure time, adsorbent dosage, and adsorbate starting concentration, was consistently examined. The maximum removal percentages of Cu 2+ ions were 92% and 98% for BP and m BP–SA, respectively. While both BP and mBP–SA achieved a maximum Mn 2+ removal efficiency of 90% under the optimized experimental conditions, mBP–SA exhibited a higher adsorption capacity (q max ), indicating improved adsorption performance, particularly at higher initial Mn 2+ concentrations. The highest possible effectiveness of removal for Cu 2+ and Mn 2+ was achieved at a starting concentration of 5 ppm. Furthermore, the kinetics and isotherms of the proposed adsorption process were investigated. Langmuir and Freundlich isotherm equations were utilized for investigating the equilibrium data in order to appraise the adsorption mechanism. The good conformity of the Cu 2+ and Mn 2+ adsorption data with the Langmuir model suggests that the adsorption process predominantly follows monolayer adsorption on relatively homogeneous surface sites. The maximum adsorption capacities (q max ) of mBP–SA were 8.70 and 3.38 mg g −1 for Cu 2+ and Mn 2+ , respectively, compared with 5.29 and 1.86 mg g −1 for BP. Meanwhile, the biosorption process obeys the pseudo 2nd order kinetic model, indicating that both BP and metal ions influence the adsorption process. Meanwhile, the biosorption process obeys pseudo 2nd order kinetic models, indicating that both BP and metal ions influence the adsorption process. This study showed that BP and m BP–SA can serve as efficient and inexpensive adsorbents for the uptake of Cu 2+ and Mn 2+ out of their aqueous combinations. Additionally, three green evaluation methods were used to evaluate the environmental impact of our proposed procedure: the Analytical Eco-Scale Assessment (ESA), Green Analytical Procedure Index (GAPI), and the Analytical GREEnness metric (AGREE).