Comment: |
apparent stability constant for I=0, for conversion to other ionic strengths, activity constants of all surface species are assumed equal to one; no electrical double layer correction to the mass laws for charged surface species; fit with U(VI) adsorption data over the entire pH range and the thermodynamic set in table 2-1 of [DKP01]; ternary surface complex involving uranyl cation, carbonate anion, and strong-site surface functional group; because only data available for pH 7.5-9 were for the system with 1µM U(VI), only a weak site ternary complex was considered; raw data of [KD01] cited in [K02b]; original reaction equation in the study: »Si(w)-OH + UO2<2+> + H2CO3 = »Si(w)-O-UO2CO3<1-> + 3 H<1+> with logK = -6.5, formation constant in aqueous solution: H2CO3 = CO3<2-> + 2H<1+> logK = -16.683 [Grenthe et al. 1992] |