Fig. 3. Trends in dissolved Fe(II) during abiotic reduction (pH 6.0) of ferrihydrite after adding aqueous Al(III) at rates equivalent to Al(III) additions with 0, 0.002, 0.008, or 0.08 g boehmite kg^–1 suspension. Aqueous Al(III) rates were 0–2667 mmol kg^–1 ferrihydrite (0–1.33 mmol kg^–1 suspension).