TABLE 1.
Biofilter performancea
| Train | Period | No. of samples | Δ0-1TOTNH3 (mg N/liter)b | % Removal (mean ± standard deviation)c |
|||
|---|---|---|---|---|---|---|---|
| TCM | BDCM | DBCM | TBM | ||||
| A | I | 6 | 2.7 ± 0.29 | 9.7 ± 6.4 | 12 ± 5.3 | ||
| II | 3 | 3.4 ± 0.26 | 24 ± 2.3 | ||||
| III | 4 | 3.1 ± 0.38 | 16 ± 7.6 | 18 ± 6.5 | 19 ± 6.3 | 16 ± 6.2 | |
| B | I | 7 | 2.1 ± 0.36 | 7.7 ± 5.2 | 13 ± 8.3 | ||
| II | 3 | 3.0 ± 0.23 | 14 ± 2.0 | ||||
| III | 4 | 2.5 ± 0.37 | 13 ± 6.2 | 14 ± 6.0 | 15 ± 5.2 | 13 ± 3.8 | |
| C | I | 6 | 2.6 ± 0.74 | 6.9 ± 6.0 | 12 ± 5.0 | ||
| II | 2 | 2.5 ± 0.62 | 17 ± 2.0 | ||||
| III | 4 | 2.8 ± 0.67 | 14 ± 5.7 | 21 ± 8.1 | 23 ± 6.0 | 18 ± 3.8 | |
| D | I | 7 | 2.0 ± 0.56 | 6.5 ± 6.5 | 13 ± 7.3 | ||
| II | 3 | 1.7 ± 0.22 | 10 ± 3.2 | ||||
| III | 4 | 2.4 ± 1.1 | 16 ± 6.9 | 16 ± 7.6 | 17 ± 8.1 | 15 ± 7.6 | |
a
Trains were nominally fed 4 mg N/liter TOTNH3 (sum of ammonia-nitrogen [NH3-N] and ammonium-nitrogen [NH4+-N]). The three operational periods were based on influent THM concentrations as follows: period I, TCM-DBCM (50 μg/liter TCM and 25 μg/liter DBCM); period II, DBCM (25 μg/liter DBCM); and period III, all THMs (15 μg/liter each of TCM, BDCM, DBCM, and TBM).
b
Δ0-1TOTNH3, TOTNH3 removed through biofilter (mean ± standard deviation).
c
TCM, trichloromethane; BDCM, bromodichloromethane; DBCM, dibromochloromethane; TBM, tribromomethane.