Fig. 14 Diffuse reflectance infrared Fourier transform (DRIFT) difference spectra of sorbed selenite on am-Fe(OH)₃ at pH 8.0: (a) analytical grade Na₂SeO₃ and (b) am-Fe(OH)₃ reacted with 0.05 M Na₂SeO₃ + 1.0 M NaCl. The reference spectrum for (b) was the am-Fe(OH)₃ equilibrated with 1.0 M NaCl