An Al2O3-supported iron oxide was developed for the
removal of Pb2+ from aqueous solutions in this study. The surface
of the FeAA adsorbent was characterized by XRD and
FTIR and was identified as -FeOOH. Furthermore, the ability
of FeAA to bind Pb2+ was tested using equilibrium, kinetic
and thermodynamic aspects.
The Langmuir and Freundlich adsorption models were used
to express the sorption phenomenon of the sorbate. The equilibrium
data were well described by the Langmuir model. In
addition, the negative Gibbs standard free energy changes confirmed
the spontaneous nature adsorption process. The positive
standard enthalpy and the entropy changes showed the endothermic
nature and irreversibility of Pb2+ adsorption, respectively.
The pseudo-second-order rate model accurately describes the kinetics of adsorption.