The oxidized NB treated with ZnCl2 was labeled (NBZOX), the oxidized
NB mixed with H3PO4 (NBPOX) and the oxidized NB activated
with KOH (NBKOX), while the adsorption of HA onto oxidized NB treated
with ZnCl2 and CO2 was named (NBZCOX). The CO2 was used as the
gasifying agent for the improvement of the porosity of the activated
carbon produced [14]