Fig. 5. Comparisons between measured (points) and modeled (curves) Cr(VI) reduction trends for columns initially exposed to (A) 1000 mg L^-1 Cr(VI) and (B) 10 000 mg L^-1 Cr(VI). Data from nonsterile soils were fit for first-order Cr(VI) reduction (finer lines, using Eq. [1]) with effective rate constants shown. The sterile soil data (Day 84 only) were fit with Eq. [5] and [6] (heavier lines, with k''' values shown). Extrapolations of these latter fits beyond Day 84 are shown as fine lines.