Table 4 Concentrations of organic acids in the digestates from the primary digester
Time (d) | Acetate (mg/L) | Propionate (mg/L) | Butyrate (mg/L) | Lactate (mg/L) | VFAS (ΣAcProBut) (mg/L) |
|---|---|---|---|---|---|
81 | 19.8 | <1 | <1 | 13.0 | 19.8 |
88 | 130 | 27.0 | <1 | <1 | 157 |
95 | 2023 | 85.2 | 38.0 | <1 | 2,146 |
102 | 8827 | 655 | 602 | <1 | 10,084 |
109 | 2586 | 119 | 44.3 | 27.8 | 2749 |
116 | 2832 | 61.0 | 24.2 | 30.5 | 2917 |
123 | 295 | 18.7 | <1 | 30.0 | 314 |
130 | 119 | 26.4 | <1 | 60.0 | 145 |
137 | 149 | 32.4 | <1 | 53.8 | 181 |
144 | 88 | 17.2 | <1 | 52.3 | 105 |
151 | 77 | 20.9 | <1 | 30.6 | 98.0 |
158 | 199 | 23.0 | <1 | 69.1 | 222 |