Table 8.
Comparison of CT values in mg-min/L for various oxidants to achieve 2-log (99%) inactivation of the given organism at 5 °C, as noted by Hoff, USEPA, 1986. ND = not determined. [177].
| Organism | Ozone | Free Chlorine | Chloramine | Chlorine Dioxide |
|---|---|---|---|---|
| pH 6–7 | pH 6–7 | pH 8–9 | pH 6–7 | |
| E. coli bacteria | 0.02 | 0.034–0.05 | 95–180 | 0.4–0.75 |
| Polio 1 virus | 0.1–0.2 | 1.1–2.5 | 770–3740 | 0.2–6.7 |
| Rotavirus | 0.006–0.06 | 0.01–0.05 | 3806–6476 | 0.2–2.1 |
| Giardia lamblia cysts | 0.5–0.6 | 47–150 | ND | ND |
| Giardia muris cysts | 1.8–2.0 | 30–630 | ND | 7.2–18.5 |