TABLE 2.
Degradation estimates for DEHP and PA in sludge and sludge-amended agricultural soila
| Sample | Substrate | Half time for initial phase (days) | Half time for late phase (days) | Initial rate of metabolism (pmol/g [dry wt]/day) |
|---|---|---|---|---|
| Sludge-amended quartz | DEHP | 39 | 51 | 45.4 |
| Sludge slurry | DEHP | 58 | 84 | 26.9 |
| Sludge-amended soil | DEHP | 58 | 147 | 25.6 |
| Sludge-amended soil + strain SDE 2 | DEHP | 9 | 35 | 219.4 |
| Sludge-amended soil | PA | 2 | 15 | 731.8 |
a
Three samples were examined in each experiment. The initial substrate concentration was 4.1 nmol of DEHP per g (dry weight) or 4.1 nmol of PA per g (dry weight). The concentration half times were estimated by using equations 2 and 4.