Fig. 6. Selected tritium (³H₂O) breakthrough curves plotted as relative concentration (C/C₀) against number of eluted pore volumes (V/V₀) with calculated best fit using either (a) the mobile–immobile model (MIM), or (b–f) the two mobile–one immobile model (2MIM) and the mobile–immobile model (MIM). Note that two different x and y axes are used.