Removal of Heavy Metals from Wastewater Using Albizia Lebbeck Seed-Based Activated Carbon

Abstract

Water, a vital resource for sustaining life, is increasingly threatened by pollution caused by industrialization, population growth, and modernization. This study evaluates the potential of Albizia lebbeck seed-based activated carbon for the removal of Chromium VI [Cr(VI)] ions from aqueous solutions. The Albizia lebbeck seed was chemically modified using 1 M phosphoric acid into activated carbon and examined based on contact time, adsorbent dosage, temperature, concentration, and pH of the wastewater. The efficiency of the preparation was evaluated using batch adsorption isotherm, Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET), and Energy Dispersive X-ray Spectroscopy (EDS). Batch adsorption results revealed that the removal of Cr (VI) ions from its aqueous solution on the studied adsorbents was influenced by the investigated parameters in varying degrees. The adsorption process was found to be endothermic and best described by the Freundlich as determined from isotherm modelling. The FTIR analysis also established the presence of more surface functional groups and sharper peaks in the activated adsorbent than the original form. The SEM microgram revealed the morphology of the prepared activated adsorbent and The activated adsorbent exhibited higher BET surface area (336.436 m²/g), pore volume (0.305 cc/g), and pore size (6.602 nm), enhancing its mesoporous nature compared to the unmodified adsorbent (236.617 m²/g), (0.215 cc/g) and (6.214 nm) which likely improved its performance. The results confirm that activated Albizia lebbeck seeds are effective adsorbents for removing chromium (VI) ions from aqueous solutions, particularly when treated with inorganic acid. This highlights their potential for removing heavy metal contaminants from industrial wastewater.

KEYWORDS

Adsorbent, Heavy metals, Activated carbon, Wastewater, Chromium.