Enhancing heavy metals filtration: Synergistic effects of banana peel-derived activated carbon and layered double hydroxides in ultrafiltration membranes

This study presents a novel approach for enhancing the performance of ultrafiltration (UF) membranes in removing heavy metals from wastewater by incorporating banana peel-derived activated carbon (BPAC) and ternary layered double hydroxides (LDH) into a polyethersulfone (PES) matrix. BPAC was synthesized via pyrolysis and fused into the polymeric matrix using the phase inversion technique. The developed PES-BPAC membranes exhibited higher permeability and maximum rejection compared to control membranes, attributed to the highly porous nature of BPAC. Further functionalization of the PES-BPAC membrane with Mg-Al-Fe-LDH at concentrations ranging from 4 to 16 % resulted in superior performance, with the 12 %LDH-BPAC membrane exhibiting the highest water flux of 354.6 LMH and 91.7 % rejection of Ni²⁺ ions. The superior composite membrane was tested in cross-flow and dead-end filtration and electrically regenerated to ensure long-term applicability. Comparative analysis with existing membranes and regeneration ability confirmed the commercial potential of the developed membranes for effective heavy metal removal from wastewater streams. This study highlights the synergistic effects of BPAC and LDH in enhancing UF membrane performance, providing an innovative and sustainable approach to wastewater treatment and biomass waste management.