Application of alumina–chitosan modified monolithic activated carbon derived from empty fruit bunches for acid mine drainage treatment

Acid mine drainage (AMD) is a major environmental problem due to its high acidity and metal content. This study aims to develop a sustainable alumina–chitosan-modified monolithic activated carbon derived from empty fruit bunches (EFB) for AMD treatment. The synthesis process involved low-temperature pyrolysis (pre-carbonization) at 110 °C, followed by calcination at 600 °C, alumina and chitosan modification, and molding into a monolithic form. The resulting material was characterized using scanning electron microscopy (SEM), 3D surface topography, X-ray diffraction (XRD), and Barrett–Joyner–Halenda (BJH) analyses. The SEM results revealed a highly porous surface with roughness values ranging from 4,800 μm to 65,600 μm and porosity between 0.62 and 0.77, corresponding to pore percentages of 61.64–76.50 %. XRD analysis confirmed the formation of a γ-Al 2 O 3 phase, with sharp peaks at 2θ = 25.4°, 31.6°, 37.8°, and 45.3°, while BJH analysis indicated a mesoporous structure (10–18 Å) and total pore volume of 0.0078 cm 3 /g. The novelty of this study lies in integrating alumina and chitosan within a monolithic carbon matrix, improving both mechanical stability and adsorption potential. Overall, the EFB-derived composite exhibits strong structural integrity and enhanced surface reactivity, demonstrating high potential as a sustainable and efficient adsorbent for AMD remediation. • EFB-derived alumina–chitosan monolith was successfully synthesized. • Calcination at 600 °C formed γ-Al 2 O 3 with improved crystallinity. • Surface roughness ranged from 4,800–65,600 μm with 0.62–0.77 porosity. • Mesoporous structure (10–18 Å) with pore volume ≈ 0.0078 cm 3 /g. • Composite shows strong potential for AMD wastewater treatment.