Table 2 Distribution of fermentative products for the six conditions
From: Total solids content: a key parameter of metabolic pathways in dry anaerobic digestion
Categories | Unit (molar %) | Wet (W) | Dry (D) | Highly dry (HD) | Similarity | Similarity |
|---|---|---|---|---|---|---|
10% ≤ TS ≤14% | 19% < TS <28% | 28% < TS ≤33% | W-D group | W-D group | ||
Gas products | Total products | 63% ± 2 | 63% ± 5 | 57% ± 5 | Similar (P = 0.34, ns) | Different (P = 1e-2*) |
Hydrogen | Gas products | 51% ± 3 | 31% ± 3 | 18% ± 6 | Different (P = 3e-7***) | Different (P = 2e-4***) |
Carbon dioxide | 49% ± 3 | 69% ± 3 | 82% ± 6 | Different (P = 3e-7***) | Different (P = 2e-4***) | |
Hydrogen associated with VFAs | Total products | 30% ± 3 | 23% ± 5 | 29% ± 2 | Different (P = 3e-2*) | Different (P = 2e-4***) |
Acetic acid | Hydrogen associated with VFAs | 62% ± 12 | 62% ± 10 | 29% ± 5 | Similar (P = 0.12, ns) | Different (P = 5e-7***) |
Butyric acid | 38% ± 10 | 38% ± 12 | 71% ± 5 | Similar (P = 0.12, ns) | Different (P = 5e-7***) | |
Other metabolites | Total products | 7% ± 2 | 14% ± 2 | 13% ± 4 | Different (P = 3e-5***) | Similar (P = 0.26, ns) |
Propionic acid | Concurrent metabolite | 23% ± 4 | 26% ± 3 | 26% ± 13 | Similar (P = 0.54, ns) | Similar (P = 0.39, ns) |
Valeric acid | 7% ± 3 | 12% ± 3 | 14% ± 3 | Different (P = 7e-4*) | Different (P = 2e-2*) | |
Caproic acid | 15% ± 7 | 1% ± 2 | 0% ± 0 | Different (P = 2e-7***) | Similar (P = 0.07, ns) | |
Lactic acid | 0% ± 0 | 0% ± 0 | 12% ± 13 | Similar (P = 0.27, ns) | Different (P = 2e-3*) | |
Ethanol | 55% ± 7 | 60% ± 7 | 52% ± 10 | Similar (P = 0.71, ns) | Similar (P = 0.12, ns) |