BIOSORPTION-BASED REMOVAL OF HEAVY METALS USING BANANA AND ORANGE PEEL FROM INDUSTRIAL WASTEWATER

The present study successfully demonstrated the potential of banana peel and orange peel as low-cost, eco-friendly biosorbents for the removal of multiple heavy metals (Pb, Cd, Cr, Cu, and Ni) from real industrial wastewater. The experimental results confirmed that agricultural waste-derived biosorbents possess significant adsorption capacity due to the presence of functional groups such as hydroxyl (–OH), carboxyl (–COOH), and amine (–NH₂), which actively participate in metal ion binding through mechanisms such as ion exchange, complexation, and surface adsorption. Among the studied metals, lead (Pb) and copper (Cu) exhibited the highest removal efficiencies, while cadmium (Cd) and nickel (Ni) showed comparatively lower removal due to competitive adsorption effects in the multi-metal system. The adsorption process was found to be strongly influenced by operational parameters, with optimum performance observed at pH 5–6, contact time of approximately 90 minutes, and biosorbent dosage of around 3 g/L. The adsorption equilibrium data were well described by the Langmuir isotherm model, indicating monolayer adsorption on a homogeneous surface, while kinetic analysis confirmed that the process follows pseudo-second-order kinetics, suggesting chemisorption as the dominant mechanism. The high correlation coefficients (R² ≈ 0.99) further validate the reliability of the developed adsorption system. Additionally, the biosorbents exhibited good regeneration and reuse potential, maintaining satisfactory removal efficiency over multiple cycles, thereby enhancing their economic feasibility. The study also highlights the practical applicability of biosorption using real industrial wastewater, bridging the gap between laboratory-scale studies and real-world implementation. Overall, the findings confirm that fruit peel-based biosorption is an effective, sustainable, and economically viable technology for heavy metal removal. This approach not only addresses wastewater pollution but also promotes waste-to-resource utilization and supports circular economy principles, making it highly suitable for large-scale and decentralized wastewater treatment applications.

1.     Ahmed, S., Rahman, M., & Hossain, K. (2025). Role of biosorbents in wastewater treatment. Journal of Cleaner Production, 312, 127–142. 2.     Ahmad, T., & Danish, M. (2024). Prospects of fruit peel biosorbents for pollutant removal. C, 10(1), 22–35. 3.     Ajmal, M., Rao, R.A.K., Ahmad, R., & Ahmad, J. (2000). Adsorption studies on orange peel for Ni removal. Journal of Hazardous Materials, 79, 117–131. 4.     Annadurai, G., Juang, R.S., & Lee, D.J. (2002). Use of cellulose-based wastes for adsorption. Journal of Hazardous Materials, 92, 263–274. 5.     Arizpe-Díaz, D.O., et al. (2026). Evaluation of cadmium removal using fruit peels. Environments, 12(4), 97. 6.     Babel, S., & Kurniawan, T.A. (2003). Low-cost adsorbents for heavy metals. Journal of Hazardous Materials, 97, 219–243. 7.     Baral, S., & Singh, R. (2021). Agricultural waste-based adsorbents. Journal of Cleaner Production, 312, 127–142. 8.     Bhatnagar, A., & Sillanpää, M. (2017). Utilization of agro-waste for water treatment. Chemical Engineering Journal, 157, 277–296. 9.     Chen, L., Wang, Y., & Zhang, H. (2023). Kinetic modeling of biosorption. Separation and Purification Technology, 354, 127–142. 10.  Chen, X., & Li, W. (2021). Surface characterization of biosorbents. Applied Surface Science, 565, 150–165.