JEQ -- Tokunaga et al. 32 (5): 1641 Figure IG6

Click on image to view larger version.

Fig. 6. (A) Plots of aqueous Fe(II) concentrations for equilibrium with ferric hydroxide versus p ${epsilon}$ . Lines are for pH 7.5 (characteristic of the experiment), and range bars indicate shifts in Fe(II) concentrations for pH 7 and 8. (B) Effective first-order rate constants for Cr(VI) reduction by Fe²⁺ as functions of the negative logarithm of the electron activity (p ${epsilon}$ ), for equilibrium with ferric hydroxide. Lines are for pH 7.5, and range bars indicate shifts in rate constants for pH 7 and 8. Also shown are ranges of measured k and estimated p ${epsilon}$ from the nonsterile soils.