Synthesis, characterization and adsorption performance of biomass-derived adsorbents for heavy metal removal from water

Heavy-metal pollution in water remains a major environmental and health concern because these contaminants are toxic, persistent, and able to accumulate in living organisms. This study examined the preparation, characterization, and adsorption behavior of adsorbents produced from agricultural biomass for the removal of toxic metals from aqueous media. The biomass precursor was converted into activated carbon through phosphoric-acid activation. The resulting material was characterized by FTIR, SEM, and BET surface-area analysis to determine its surface chemistry, morphology, and pore properties. Batch adsorption tests were then performed to assess the removal of Pb(II), Cd(II), and Cr(VI) under different operating conditions, including pH, contact time, initial concentration, adsorbent dosage, and temperature. The adsorbent exhibited strong removal performance, with equilibrium data best represented by the Langmuir model and kinetic behavior aligning more closely with the pseudo-second-order model. Thermodynamic evaluation also indicated that adsorption occurred spontaneously. Overall, the findings suggest that biomass-derived activated carbon offers a low-cost and sustainable option for treating metal-contaminated water.