Time (h) Volatile fatty acids (mg/l)   Acetic acid Butyric acid Propionic acid 0 4800 ± 320 490 ± 45 480 ± 52 12 4254 ± 246 284 ± 27 265 ± 24 24 3212 ± 165 178 ± 28 134 ± 18 36 2234 ± 124 102 ± 26 94 ± 14 48 1456 ± 114 51 ± 14 32 ± 12

Table 1: Composition of volatile fatty acids estimated by HPLC during different time intervals at OLR2.