A novel starch‐based composite hydrogel enhanced by activated charcoal from the banana peel for water decontamination.

The efficient removal of potential toxic elements (PTEs) from aqueous systems is an important challenge in water purification and industrial effluent treatment. Starch‐based hydrogels have shown promise in this context due to their unique properties, such as high absorption capacity and water retention. This work synthesized a novel hydrogel with and without activated charcoal (AC) from banana peel (5 wt.%) and trisodium citrate as a crosslinking agent and starch to remove PTEs. These hydrogels were characterized by Fourier‐transformed infrared (FTIR), scanning electron microscopy, TGA, XRD, water absorption, and zero‐charge point techniques. Subsequently, the affinity of AC, neat hydrogel, and the composite hydrogel for removing Cr6+, Cd2+, Ni2+, Mn2+, Zn2+, and Cu2+ in aqueous solution was evaluated. FTIR confirmed a crosslinking reaction between the starch molecules and the crosslinking agent (trisodium citrate). Besides, the addition of hydrogel+5%AC altered the crosslinking process. Adding AC to the hydrogel composite increased crystallinity, thermal stability, and porous size. The highest removal efficiency of neat hydrogel and hydrogel+5%AC was for Cr6+, obtaining 83.2% and 98.5%, respectively. As for the AC, the removal of Cu2+ was satisfactory, with 80.4%. Thus, hydrogel+5%AC proves to be a highly viable adsorbent for posttreatment of wastewater due to its ability to efficiently remove PTEs. [ABSTRACT FROM AUTHOR]