Biosorption of chromium and nickel from aqueous solution using pine cones, eucalyptus bark, and moringa pods: a comparative study

摘要

Low-cost local plants (eucalyptus bark, moringa pods, pine cones) have been successfully used to remove heavymetals from simulated wastewater. Two types of heavy metals were chosen to study the removal capacity, nickel(Ni) and chrome (Cr), with a concentration of 400, 600, 900 ppm. The results show that moringa pods have thebest removal capacity for heavy metals with percentages of 90–99% for both metals, Ni and Cr, for the eucalyptusbark the removal capacity percentages reach 50–98%, while for the pine cones revealed a lower removingcapacity with percentages of 40–99%, indicating that this is the lowest removal capacity. The data has beenbest fitted to the Langmuir adsorption model for all plants, while the Freundlich adsorption model could notfit the obtained results at the experimental conditions. The kinetic study has revealed that the first-order kineticmodel successfully describes the kinetics of Ni adsorption, while the second-order describes the kinetics of Cradsorption. The removal of heavy metals (Ni, Cr) was obtained when moringa was used; its highest removal efficiencywas reached within 20 minutes. On the other hand, other plants (eucalyptus bark, pine cone) removalefficiency was attained in more than two hours. The removal is remarkable even at a high concentration ofheavy metals, especially with the moringa plant.