Table 3 Initial pH of the culture medium with different VFA concentrations and without pH adjustment
VFA types | Acetic acid | Propionic acid | Butyric acid | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
VFA Conc. (g/L) | 2.5 | 5 | 10 | 20 | 2.5 | 5 | 10 | 20 | 2.5 | 5 | 10 | 20 |
pH value | 3.80 | 3.64 | 3.42 | 2.51 | 3.92 | 3.77 | 3.58 | 2.63 | 3.96 | 3.81 | 3.69 | 2.68 |