Table 1 Studied AD reactors and their physicochemical characteristics
Reactor type | Main feeding substrate | AD unit | Reactor acronym | Reactor category | pH | Temp. range °C | TIC | NH4–N | TS | VS |
|---|---|---|---|---|---|---|---|---|---|---|
On-farm AD reactors fed mainly with agricultural residues | Maize and grass silages, cow manure and slurry (around 70%), bread | U-1 | B | Fd | 7.9 ± 0.2 | 39–40 | 3.4 ± 0.9 | 3.3 ± 0.9 | 8.6 ± 2.2 | 72.1 ± 4.8 |
Maize silage, cow manure (around 70%), minor food waste | U-2 | C | Fd | 8.0 ± 0.1 | 42–44 | 4.7 ± 0.6 | 3.9 ± 1.1 | 10.2 ± 1.4 | 72.6 ± 2.9 | |
AD reactors treating a mixture of agricultural residues (mainly manure) and bio-waste | Cow manure and slurry, grass, maize and cereal silages, diary waste | U-3 | BKA | Fd-1 | 7.6 ± 0.2 | 33–39 | 2.7 ± 0.4 | 2.1 ± 0.6 | 8.3 ± 0.6 | 72.9 ± 2.9 |
BKB | Fd-2 | 7.7 ± 0.2 | 2.9 ± 0.6 | 2.1 ± 0.6 | 8.0 ± 0.9 | 72.5 ± 2.9 | ||||
BKC | Pd-1 | 7.9 ± 0.2 | 3.3 ± 0.3 | 2.6 ± 0.9 | 7.2 ± 0.3 | 69.5 ± 1.9 | ||||
BKD | Pd-2 | 7.9 ± 0.2 | 3.3 ± 0.4 | 2.6 ± 0.7 | 7.3 ± 0.4 | 69.1 ± 1.8 | ||||
BKE | St | 7.8 ± 0.2 | nh | 3.6 ± 0.3 | 2.9 ± 0.5 | 6.7 ± 0.5 | 67.1 ± 1.9 | |||
Cow manure and slurry, cereal waste, waste from food industries, maize silage, grass | U-4 | F-R1 | Fd-1 | 7.8 ± 0.1 | 39 | 3.9 ± 0.5 | 3.5 ± 0.8 | 10.1 ± 0.8 | 65.9 ± 1.9 | |
F-R2P | Pd | 7.9 ± 0.1 | 5.6 ± 0.5 | 4.5 ± 0.8 | 8.5 ± 0.6 | 61.2 ± 1.2 | ||||
F-R3 | Fd-3 | 7.9 ± 0.1 | 4.8 ± 0.6 | 3.8 ± 0.8 | 8.8 ± 0.5 | 62.5 ± 1.6 | ||||
F-stock | St | 7.9 ± 0.1 | nh | 6.2 ± 0.5 | 5.0 ± 0.9 | 7.6 ± 0.4 | 57.6 ± 2.5 | |||
Manure, cereal waste, grass silage, organic waste from supermarkets and canteens | U-5 | MbioA | Fd-1 | 7.5 ± 0.2 | 37–38 | 3.5 ± 0.7 | 3.6 ± 1.5 | 6.7 ± 0.9 | 66.5 ± 2.5 | |
MbioB | Fd-2 | 7.6 ± 0.2 | 2.3 ± 0.4 | 1.9 ± 1.1 | 10.8 ± 3.7 | 70.6 ± 2.6 | ||||
MbioC | Pd | 7.6 ± 0.1 | 3.3 ± 0.5 | 2.7 ± 1.1 | 8.8 ± 0.9 | 68.1 ± 2.2 | ||||
MbioD | St | 7.6 ± 0.2 | nh | 3.5 ± 0.4 | 2.8 ± 0.6 | 7.7 ± 1.7 | 65.7 ± 2.4 | |||
Manure, green waste, maize silage, waste from food industries | U-6 | NK | Fd | 7.6 ± 0.3 | 36–37 | 3.4 ± 0.6 | 2.4 ± 0.8 | 7.8 ± 0.9 | 66.2 ± 2.2 | |
Municipal and green waste treating AD reactors | Yard green waste (leaves, trees), organic waste from households and canteens | U-7 | MK-beg | Fd | 7.8 ± 0.2 | 39 | 4.9 ± 0.8 | 3.6 ± 1.5 | 21.6 ± 1.6 | 50.8 ± 2.7 |
MK-mid | 7.8 ± 0.2 | 4.6 ± 0.8 | 3.4 ± 1.5 | 22.2 ± 1.3 | 51.7 ± 3.2 | |||||
MK-end | 7.8 ± 0.1 | 4.6 ± 0.9 | 3.5 ± 1.6 | 21.8 ± 1.7 | 50.7 ± 2.8 | |||||
WWTP-specific AD reactors | Thickened sewage sludge from wastewater treatment | U-8 | P | Fd | 7.2 ± 0.1 | 35 | 1.3 ± 0.3 | 0.4 ± 0.5 | 2.5 ± 0.4 | 47.7 ± 3.3 |
U-9 | S | Fd | 7.1 ± 0.1 | 36 | 1.2 ± 0.2 | 0.7 ± 0.5 | 3.8 ± 0.4 | 55.6 ± 1.8 | ||
U-10 | BT | Fd | 7.2 ± 0.1 | 36 | 1.4 ± 0.2 | 1.3 ± 0.9 | 3.0 ± 0.2 | 49.0 ± 1.6 |