Production of activated carbon from eucalyptus bark for removal of heavy metals from wastewater

Heavy metal pollution has emerged as a significant environmental concern. This study investigated the removal and recovery of copper and cobalt heavy metals from aqueous solutions using activated carbon derived from eucalyptus bark. The influence of various parameters, including pH, agitation speed, initial metal concentration, contact time, and adsorbent dosage, on the adsorption of copper and cobalt ions onto the activated carbon was examined. Batch experiments were conducted to evaluate the adsorption process. The characteristics of the prepared adsorbent were analyzed using scanning electron microscopy. The optimal experimental conditions were determined to be pH 6, agitation speed of 250 rpm, initial metal ion concentration of 10 mg/L, contact time of 60 minutes, and adsorbent dosage of 3 g/L at 25 °C. Among the isotherm models tested, the Freundlich isotherm model exhibited the best fit for the equilibrium adsorption of both copper and cobalt ions, with correlation coefficients (R²) of 0.965 and 0.9798, respectively. Kinetic studies revealed that the adsorption process followed the pseudo-second-order kinetic model. The results demonstrated that the activated carbon produced from eucalyptus bark is an effective adsorbent for the removal of copper and cobalt ions from aqueous solutions.