Table 4.
Start-up of the UASB reactor.
| Fixed Parameter | Units | Value | ||||
|---|---|---|---|---|---|---|
| Temperature | °C | 35 ± 1 | ||||
| HRT | hr. | 24 | ||||
| pH | ‒ | 6.5 | ||||
| Experimental Run | Day | Influent COD concentration (g/L) | Feed flow rate (L/d) | Maximum COD removal efficiency | OLR (g/L d−1) | Average effluent pH |
| (%) | ||||||
| Batch feed | ||||||
| Stage I | 1–11 | 0.4 | 3 | 98.6 | 0.2 | 6.7 |
| Continuous feed | ||||||
| Stage II | 11–34 | 0.8 | 3 | 90.3 | 0.4 | 6.95 |
| Stage III | 34–49 | 1.4 | 3 | 80.4 | 0.7 | 6.87 |
| Stage IV | 49–67 | 2 | 3 | 73.6 | 1.0 | 6.63 |
| Stage V | 67–74 | 3 | 3 | 71.0 | 1.5 | 6.72 |
| Stage VI | 74–86 | 4 | 3 | 70.2 | 2.0 | 6.85 |
| Stage VII | 86–95 | 5 | 3 | 73.0 | 2.5 | 6.77 |
| Stage VIII | 95–100 | 6 | 3 | 70.0 | 3.0 | 6.60 |
| Stage IX | 100–106 | 10 | 3 | 72.5 | 5.0 | 6.7 |
| Stage X | 106–113 | 14 | 3 | 72.1 | 7.0 | 6.8 |
| Stage XI | 113–120 | 20 | 3 | 65.0 | 10.0 | 7.1 |
| Stage XII | 120–127 | 30 | 3 | 42.0 | 15.0 | 7.3 |