Abstract
The reaction between arsenite and iodate at 25 °C and pH 2.25 in a stirred tank reactor exhibits bistability over a range of flow rates and input arsenite and iodate concentrations. Observed steady-state and I2 concentrations and points of transition between bistable and unistable behavior are in excellent agreement with values calculated from a simple model consisting of three overall component processes: (A) I03" + 3H3As03 = + 3H3As04; (B) I03~ + 5 + 6H+ = 3I2 + 3H20; (C) I2 + H3As03 + H20 = 2 + H3As04 + 2H+. Implications for the recently discovered arsenite-iodate-chlorite-oscillating reaction are discussed.