Fig. 10 Diffuse reflectance infrared Fourier transform (DRIFT) difference spectra of sorbed selenate on am-Fe(OH)₃ reacted at pH 5.0 with 0.01 M Na₂SeO₄ + 1.0 M NaCl. Spectra were collected for both wet (40% water by weight) and air-dried Fe oxide suspensions using a Bio-Rad FTS-175C immediately after mixing with KBr at a solid to KBr ratio of 5 to 95 mg