Fig. 6

Surface complexation models describing Am(III) adsorption to γ-alumina. Experimental conditions from (1) Righetto et al. [36] and (2) Righetto et al. [35] and full experimental conditions are summarized in Additional file 1: Table S7. The contributions of each individual surface species are illustrated in Additional file 1: Figures S13 (CDM_Eu) and S14 (DDL_Eu). The CDM_Eu curve represents a CD-MUSIC model developed by employing europium sorption data, the CDM_Am curve represents a CD-MUSIC model developed by employing americium sorption data, the DDL_Eu curve represents a DDL model developed by employing europium sorption data, and the DDL_Am curve represents a DDL model developed by employing americium sorption data. The curves labeled Kumar et al. _CCM, Rabung et al. _CCM and Morel et al. _DDL are previous models sourced from literature [26,27,28]