Fig. 7. Proton/anion coadsorption stoichiometries on Al oxide. No NaCl added. Anions are selenate and selenite at 0.001 M initial concentrations. Data extrapolated from Se adsorption and proton adsorption data, and corrected for Cl adsorption data (Eq. [6]) or not (Eq. [3]). Data from the pH-stat method are also shown