Table 7.
N and P reduction and cost efficiency for woodchip bioreactors
| Name of reactor | Serupgård | Egsmarken | Dundelum | Gyldenholm |
|---|---|---|---|---|
| Reactor size (m2) | 271 | 526 | 652 | 1431 |
| TN reduction (kg N/year) | 123 | 162 | 318 | 612 |
| Standard effect (kg N/yr/0.2 CW ha) | 908 | 617 | 975 | 855 |
| TN removal % | 27 | 38 | 48 | 17 |
| TP reduction 1st year (kg P/yr) | -9 | -20 | -70 | -30 |
| TP reduction 2nd year (kg P/yr) | 3 | 1 | 9 | 3 |
| Cost efficiency (DKK/kg N) | 368 | 423 | 273 | 359 |
| Cost efficiency (DKK/kg N) without pump | 368 | 423 | 273 | 300 |
| Cost efficiency (DKK/kg P) | 17.415 | 52.727 | 8.266 | 73.321 |
The P effect is typically negative for the first year since P from the biomaterial is released into the nearby stream, so the year 2 effect was used instead. TN removal and efficiency are based on Table 3. TN effect is based on the average effect listed in Table 3 multiplied by the volume of Serupgård (434 + 473.5 g N m−3 yr−1)/2* 271 m3 * 1000 = 123 kg N yr−1. Note: DKK 100 = $14.41 (exchange rate on 25.4.2022)