adsorption isotherm data from [HPQ74], ionic strength 1, 0.5, 0.001 M NaCl, site protolysis reference [GS84] (average values from literature of various aluminium oxides); FITEQL/MICROQL; original equation: »Al-OH + H3PO4 = »Al-PO4<2-> + H2O + 2H<1+> with log K = -3.75, formation constant in aqueous solution: PO4<3-> + 3H<1+> = H3PO4 logK = 21.702 [GFFGN03]