TABLE 2.
Oocyst recovery efficiencies from seeded 10-liter samples with and without pellet adjustment prior to oocyst capture
| Water sample | pH during oocyst capture | Oocyst seed densitye | Turbidity (NTU)c | Recovery efficiency (%)d |
|---|---|---|---|---|
| Rio Grande 1a | 7.28 | 1,280 | 106.0 | 24.7 |
| 7.00 | 1,280 | 106.0 | 59.2 | |
| Rio Grande 2b | 7.42 | 127,000 | 159.0 | 0.4 |
| 7.00 | 127,000 | 159.0 | 27.9 | |
| Rio Grande 2a | 7.42 | 127,000 | 159.0 | 27.5 |
| 7.00 | 127,000 | 159.0 | 59.8 | |
| Arkansas 1a | 7.28 | 1,063 | 1.7 | 32.8 |
| 7.00 | 1,063 | 1.7 | 55.8 | |
| Cobb Countya | 7.12 | 131 | 9.9 | 19.8 |
| 7.00 | 131 | 9.9 | 51.9 | |
| Charleroia | 7.24 | 105 | 6.8 | 43.0 |
| 7.00 | 105 | 6.8 | 60.3 | |
| Nottinghama | 7.28 | 205 | 21.6 | 6.8 |
| 7.00 | 205 | 21.6 | 15.6 | |
| Hetch Hetchya | 7.51 | 156 | 0.2 | 14.1 |
| 7.00 | 156 | 0.2 | 29.4 |
a
The sample was concentrated by hollow-fiber ultrafiltration.
b
The sample was concentrated by using the Envirochek filter.
c
NTU, nephelometric turbidity units.
d
The mean recovery efficiencies were 47.4% (SD = 11.5%) for adjusted samples (including four samples with pH 7.0 after the addition of the SL buffers [Table 3]) and 21.0% (SD = 13.0%) for nonadjusted samples (excluding the Rio Grande sample concentrated by use of the Envirochek filter).
e
Values are numbers of oocysts per 10 liters.