Appendix B: CT values for inactivation of viruses
Table B-1: CT values for inactivation of viruses by free chlorine (mg·min/L), based on HAV (U.S. EPA, 2006a)
| Temperature (°C) |
Log inactivation |
| 2 |
3 |
4 |
| pH 6-9 |
pH 10 |
pH 6-9 |
pH 10 |
pH 6-9 |
pH 10 |
| 0.5 |
6 |
45 |
9 |
66 |
12 |
90 |
| 5 |
4 |
30 |
6 |
44 |
8 |
60 |
| 10 |
3 |
22 |
4 |
33 |
6 |
45 |
| 15 |
2 |
15 |
3 |
22 |
4 |
30 |
| 20 |
1 |
11 |
2 |
16 |
3 |
22 |
| 25 |
1 |
7 |
1 |
11 |
2 |
15 |
Table B-2: CT values for inactivation of viruses by chloramine (mg·min/L), based on HAV (AWWA, 1991; U.S. EPA, 2006a)
| Temperature (°C) |
Log inactivation |
| 2 |
3 |
4 |
| ≤1 |
1243 |
2063 |
2883 |
| 5 |
857 |
1423 |
1988 |
| 10 |
643 |
1067 |
1491 |
| 15 |
428 |
712 |
994 |
| 20 |
321 |
534 |
746 |
| 25 |
214 |
356 |
497 |
Table B-3: CT values for inactivation of viruses by chlorine dioxide (mg·min/L), based on HAV (pH 6-9) (AWWA, 1991; U.S. EPA, 2006a)
| Temperature (°C) |
Log inactivation |
| 2 |
3 |
4/th> |
| ≤1 |
8.4 |
25.6 |
50.1 |
| 5 |
5.6 |
17.1 |
33.4 |
| 10 |
4.2 |
12.8 |
25.1 |
| 15 |
2.8 |
8.6 |
16.7 |
| 20 |
2.1 |
6.4 |
12.5 |
| 25 |
1.4 |
4.3 |
8.4 |
Table B-4: CT values for inactivation of viruses by ozone (mg·min/L), based on poliovirus 1 (AWWA, 1991; U.S. EPA, 2006a)
| Temperature (°C) |
Log inactivation |
| 2 |
3 |
4 |
| ≤1 |
0.9 |
1.4 |
1.8 |
| 5 |
0.6 |
0.9 |
1.2 |
| 10 |
0.5 |
0.8 |
1 |
| 15 |
0.3 |
0.5 |
0.6 |
| 20 |
0.25 |
0.4 |
0.5 |
| 25 |
0.15 |
0.25 |
0.3 |
