Effect of Inorganic Carbon on Ozone Self-Decomposition

The effect of inorganic carbon on ozone self-decomposition was examined in this study. Experiments were carried out under a wide concentration range of inorganic carbon of 0–30 mgC/L. First, the rate constant in the overall description model with nth order reaction on dissolved ozone was evaluated. A clear difference in the rate constants with and without inorganic carbon was observed even when the concentration of inorganic carbon was as low as 3 mgC/L; the difference with and without inorganic carbon was almost one order of magnitude. Reaction rate constant was lower with an increase of inorganic carbon concentration. The reaction rate constants were in the range from 1.4 × 10−5–1.9 × 10−4 (mg/L)−1sec.−1 under pH of 6.8–8.1 and inorganic carbon concentration of 6–30 mgC/L and converged on the order of 1.0 × 10−4 (mg/L)−1sec.−1. The difference of the second-order reaction rate constant under the practical range of pH and inorganic carbon concentration was one order of magnitude at most. Depression of ozo...