Table 2.
Average values of the concentrations of total alkalinity (TA), total volatile acids (TVA) of the influents and effluents; ratios IA/PA and TVA/TA of the effluents; and OLR applied during the operation of the UASB reactors (R1 and R2) for vinasse treatment.
| Attributes | R1 |
R2 |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| OLR (g totalCOD (L d)−1) | 0.2–2.5 | 2.5–5.0 | 5.0–7.5 | 7.5 | 0.2–2.5 | 2.5–5.0 | 5.0–7.5 | 7.5–11.5 | 11.5 |
| Operation days | (0–115) | (116–147) | (148–186) | (187–229) | (0–115) | (116–147) | (148–172) | (173–193) | (193–229) |
| pH | |||||||||
| Influent | 6.94 | 6.51 | 6.80 | 6.80 | 6.94 | 6.51 | 6.80 | 6.80 | 6.48 |
| vc | 2.7 | 0.3 | 4.4 | 2.8 | 2.7 | 0.3 | 4.4 | 2.9 | 8.8 |
| Effluent | 7.41 | 7.88 | 7.89 | 7.82 | 7.52 | 7.88 | 7.93 | 7.98 | 7.71 |
| vc | 4.5 | 2.8 | 1.8 | 7.8 | 4.5 | 2.4 | 1.4 | 1.0 | 3.3 |
| TA (mg L−1 CaCO3) | |||||||||
| Influent | 216 | 781 | 2349 | 4828 | 216 | 781 | 873 | 2284 | 4386 |
| vc | 38 | 31 | 46 | 17 | 38 | 31 | 25 | 40 | 28 |
| Effluent | 532 | 2529 | 4280 | 6100 | 558 | 2517 | 3394 | 4090 | 6288 |
| vc | 64 | 20 | 20 | 29 | 57 | 34 | 24 | 18 | 20 |
| TVA (mg L−1 CH3COOH) | |||||||||
| Influent | 158 | 943 | 1599 | 3050 | 158 | 943 | 1262 | 2596 | 4663 |
| vc | 77 | 44 | 37 | 6 | 78 | 44 | 30 | 11 | 10 |
| Effluent | 60 | 388 | 623 | 1728 | 61 | 328 | 499 | 454 | 2722 |
| vc | 48 | 67 | 23 | 23 | 43 | 56 | 15 | 16 | 48 |
| IA/PA | |||||||||
| Effluent | 0.32 | 0.18 | 0.24 | 0.35 | 0.32 | 0.16 | 0.36 | 0.23 | 0.86 |
| vc | 76 | 28 | 16 | 26 | 69 | 31 | 30 | 33 | 70 |
| TVA/TA | |||||||||
| Effluent | 0.13 | 0.15 | 0.14 | 0.31 | 0.12 | 0.13 | 0.15 | 0.11 | 0.50 |
| vc | 34 | 47 | 13 | 45 | 36 | 39 | 15 | 8 | 58 |
OLR, organic loading rate; IA, intermediary alkalinity; PA, partial alkalinity; vc, variation coefficient (%).