Fig. 5 Concentrations of aqueous As(T), As(V), and As(Ill) vs. time as Pt electrode E_H decreased in a stirred goethite suspension with a high As:Fe molar ratio (0.04). Suspension was inoculated with a CN-0 population on day 3 and N₂(g) replaced O₂(g) on Day 4 to promote reduction. Sulfide levels ranged from 5 x 10^-6 to 8 x 10^-5 M