Avocado seeds valorization as adsorbents of priority pollutants from water

This study has focused on the synthesis of lanthanum-, cerium- and calcium-functionalized adsorbents to remove heavy metal ions from aqueous solutions. Avocado seeds were used as a feedstock to obtain carbon-based adsorbents via pyrolysis and these adsorbents were further functionalized with lanthanum, cerium and calcium species using different experimental conditions to improve its adsorption properties. These adsorbents were utilized for the adsorption of heavy metals from aqueous solutions. At tested experimental conditions, the raw adsorbent showed an adsorption capacity of 7.04, 10.91, 11.41 and 6.38 mg/g for cadmium, nickel, copper and zinc, respectively. These adsorption capacities increased up to 70 % after adsorbent surface functionalization. These results suggested that the adsorption capacity of avocado-based adsorbents appeared to be dependent of the adsorbate properties.