TABLE 1.
Monensin concentrations in the influents and the effluents of the anaerobic digesters
| Period | Days | Low A |
Low Ba |
Fastb |
Slow |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Manurec | Monensin concn (mg · liter−1)d |
Manurec | Monensin concn (mg · liter−1)d |
Manurec | Monensin concn (mg · liter−1)d |
Manurec | Monensin concn (mg · liter−1)d |
||||||
| Influente | Effluent (day) | Influente | Effluent (day) | Influente | Effluent (day) | Influente | Effluent (day) | ||||||
| Startup | 1–114 | M0 | 0 | NAf | M0 | 0 | NA | M0 | 0 | NA | M0 | 0 | NA |
| P1 | 115–202 | M0 | 0 | NDg (201) | M0 | 0 | ND (201) | M0 | 0 | ND (201) | M0 | 0 | ND (201) |
| P2 | 203–216 | M200 | 0.09 | NA | M200 | 0.09 | NA | M0+ | 0.09 | NA | M0 | 0 | NA |
| 217–230 | M300 | 0.12 | NA | M300 | 0.12 | NA | M0+ | 0.12 | NA | M0 | 0 | NA | |
| 231–244 | M400 | 0.15 | ND (231) | M400 | 0.15 | ND (231) | M0+ | 0.15 | ND (231) | M0 | 0 | ND (231) | |
| 245–264 | M500 | 0.19 | NA | M400 | 0.15 | NA | M0+ | 0.19 | NA | M0 | 0 | NA | |
| P3 | 265–280 | M500 | 0.19 | 0.12 (267) | M500 | 0.19 | ND (267) | M0++ | 1 | 0.11 (267) | M0 | 0 | ND (267) |
| 281–306 | M500 | 0.19 | 0.14 (301) | M500 | 0.19 | 0.12 (301) | M0++ | 5 | 2.29 (301) | M0 | 0 | ND (301) | |
| M500 | 0.19 | NA | M500 | 0.19 | NA | M0++ | 5 | 2.73 (306) | M0 | 0 | NA | ||
| P4 | 307–320 | M500 | 0.19 | NA | M500 | 0.19 | NA | Stopped | M0++ | 1 | NA | ||
| 321–338 | M500 | 0.19 | 0.11 (331) | M500 | 0.19 | 0.11 (331) | Stopped | M0++ | 2 | 0.81 (331) | |||
| 339–352 | M500 | 0.19 | NA | M500 | 0.19 | NA | Stopped | M0++ | 3 | NA | |||
| 353–366 | M500 | 0.19 | 0.13 (365) | M500 | 0.19 | 0.13 (355) | Stopped | M0++ | 4 | 1.80 (365) | |||
| 367–383 | M500 | 0.19 | 0.14 (383) | Stopped | Stopped | M0++ | 5 | 2.55 (383) | |||||
a
M500 manure batch was started on day 267 and discontinued on day 355 of the operating period.
b
Discontinued on day 306 of the operating period.
c
M200, M300, M400, and M500 refer to the four batches of manure from monensin feed-dosed cows (corresponding to the 194, 320, 432, and 546 mg · d−1 monensin dosing rates, respectively). M0+ or M0++ indicates that monensin was added directly to control cow (M0) manure.
d
Detection limit was 0.10 mg · liter−1.
e
Values are based on dilution (manure was diluted before feeding).
f
NA, measurement not available.
g
ND, monensin not detected.