TABLE 2.
Ct values for inactivation of planktonic and drinking water biofilm-associated L. pneumophila using free chlorine and monochloraminea
|
Ct value (mg min liter−1) |
||||||
|---|---|---|---|---|---|---|
| Inactivation Ct | Planktonic LpP1s1 |
Drinking water biofilm-associated LpP1s1 |
||||
| Free chlorine | Monochloramine | Lowest | 2nd lowest | 2nd highest | Highest | |
| 2-log10 | ND | 5.35 | Free chlorine PVC, 8.86 | Free chlorine Cu, 13.18 | Monochloramine PVC, 17.16 | Monochloramine Cu, 34.86 |
| 3-log10 | 0.11 | 6.58 | Free chlorine PVC, 36.11 | Free chlorine Cu, 50.83 | Monochloramine Cu, 55.38 | Monochloramine PVC, 62.80 |
| 4-log10 | 0.30 | 7.81 | Free chlorine PVC, 63.67 | Monochloramine Cu, 75.90 | Free chlorine Cu, 88.48 | Monochloramine PVC, 108.44 |
a
Abbreviations: ND, not determined; Cu, copper; LpP1s1, L. pneumophila strain Philadelphia-1 serogroup 1; PVC, polyvinyl chloride. Ct values (concentration × time) are expressed as mg min liter−1. Data were generated from two independent experiments, except for MA Cu. For planktonic and Cu samples, there were three replicates per experiment (n = 6), except for MA Cu (n = 3). For PVC samples, there were two replicates per experiment (n = 4).