Sorption/desorption differences among three ferrihydrites prepared by different synthesis methods

► Fh was prepared under three different conditions. ► Three Fhs exhibit different adsorption capacity for Pb(II) ions. ► The degree of reversible adsorption of Pb(II) ions on the three Fhs was evaluated. ► Effect of aging of Fh on its ability to bind Pb(II) ions was studied. ► The adsorption property of Pb(II) on dense and gel samples was compared.