Table 1.
CDP performance summary
| Parameter | Mean (range) CDP performance summarya |
|||||
|---|---|---|---|---|---|---|
| Room temp, no pH adjustment (reference) |
5°C, no pH adjustment |
Room temp, pH 9 |
||||
| Before treatment | 30 min after treatment | Before treatment | 30 min after treatment | Before treatment | 30 min after treatment | |
| E. coli (MPN/100 ml)b | 7.3 × 105 (5.9 × 105 to 1.0 × 106) | 1.0 × 100 (<1 × 100 to 2.0 × 100) [78] | 7.3 × 105 (5.9 × 105 to 1.0 × 106) | 3.3 × 100 (<1 × 100 to 1.3 × 101) [11] | 4.6 × 105 (2.7 × 105 to 7.0 × 105) | 1.2 × 100 (<1 × 100 to 3 × 101) [56] |
| Total coliforms (MPN/100 ml)b | 2.1 × 106 (1.4 × 106 to 2.8 × 106) | 4.0 × 100 (<1 × 100 to 4.3 × 101) [11] | 2.1 × 106 (1.7 × 106 to 2.8 × 106) | 1.5 × 102 (3.7 × 100 to 5.5 × 102) [0] | 1.8 × 106 (1.5 × 106 to 2.8 × 106) | 2.6 × 101 (1 × 100 to 1.7 × 102) [0] |
| Turbidity (NTU) | 97 (91 to 113) | 1.7 (1.5 to 1.9) [100] | 97 (92 to 104) | 9.2 (6.0 to 14) [0] | 101 (93 to 111) | 2.5 (1.8 to 3.7) [100] |
| Free Cl2 (mg/liter) | ND | 0.09 (0.08 to 0.11) [0] | ND | 0.07 (0.07 to 0.08) [0] | ND | 0.09 (0.07 to 0.11) [0] |
| pH | 7.2 (7.2 to 7.2) | 6.4 (6.3 to 6.5) [100] | 7.2 (7.2 to 7.2) | 6.4 (6.3 to 6.5) [100] | 9.0 (8.9 to 9.2) | 6.8 (6.7 to 6.9) [100] |
| Temp (°C) | 21.0 (20.6 to 21.3) | 21.4 (20.9 to 21.7) | 6.0 (5.3 to 6.4) | 6.6 (6.2 to 6.8) | 20.8 (20.7 to 20.9) | 21.1 (21.1 to 21.2) |
a
Unless otherwise indicated, results are shown as mean (range) [% of samples within recommended guidelines (2) or below detection limit (for total coliforms)]. ND, not determined.
b
Geometric means used for microbial indicator data.