Fig. 1. Oxyanion adsorption on goethite as a function of pH. (A) Arsenite adsorption for two initial solution concentrations (0.05 and 0.10 mM). (B) Silicic acid adsorption as a function of pH for three initial solution concentrations (0.10, 0.50, and 1.00 mM). Symbols represent experimental data, lines represent predicted Si and As(III) adsorption for the optimized Charge Distribution Multisite Surface Complexation (CD MUSIC) model fit to experimental data (Log K values listed in Table 1). Suspension density 1 g L^–1, background electrolyte 0.01 M NaNO₃.