Valorization of Banana Peel Waste into Advanced Adsorbent Beads for the Removal of Emerging Pollutants from Wastewater

This study addresses environmental concerns by utilizing banana peel waste to develop innovative adsorbent materials for wastewater treatment, aligning with circular economy principles. Spherical beads were synthesized from sodium alginate mixed with various banana peel-based materials, including pure powder (PBP), activated carbon (AC), and magnetic activated carbon (MAC). These beads were evaluated for their efficiency in removing tetracycline (TC) and hexavalent chromium (Cr(VI)) as model pollutants representing antibiotics and heavy metals, respectively. Characterization of the beads revealed functional groups and thermal stability conducive to effective adsorption. Adsorption trials demonstrated that MAC beads achieved the highest removal efficiencies, up to 92% for TC and 79% for Cr(VI). The adsorption process followed pseudo-second-order kinetics and Langmuir isotherms. Remarkably, the beads retained a significant adsorption capacity across reuse cycles, indicating their regenerative potential. Comparisons with other adsorbents highlight the competitive performance of these banana peel-based materials. The results emphasize the potential of banana peel-derived adsorbents as cost-effective, sustainable solutions for mitigating emerging pollutants in water systems, promoting waste valorization and environmental protection. The research demonstrates a novel approach to sequential adsorption without intermediate regeneration, showing that the beads can effectively remove both tetracycline and chromium (VI) in successive cycles. This finding is particularly significant because it reveals that the presence of previously adsorbed chromium actually enhanced the beads' capacity for tetracycline removal in the second cycle, suggesting a synergistic effect that had not been previously reported in the literature. These innovations contribute meaningfully to both waste valorization and water treatment technologies, offering new insights into the development of multi-functional adsorbents from agricultural waste materials.