TABLE 1.
Performance summary for the wastewater treatment plant during the 3 months of sampling
| Process or parameter | Value for sample taken in:
|
||
|---|---|---|---|
| January 1995 | February 1995 | April 1995 | |
| Activated sludge process | |||
| Influent STOCb load (lb/day) | 121,927 | 128,465 | 149,909 |
| Influent methanol concn (mg/liter) | 101 | 124 | 108 |
| Influent acetic acid concn (mg/liter) | 484 | 422 | 516 |
| Flow split into 3 aeration basins (1/2/3) | 40/40/20 | 40/40/20 | 40/40/20 |
| Sludge age (days) | 12.1 | 15.4 | 11.8 |
| Solids inventory (tons) | 734 | 815 | 752 |
| Basin temp (°F) | 87.7 | 85.8 | 95.3 |
| Sludge volume index (g/ml) | 199 | 202 | 140 |
| Total filament rating (0–6)a | 3.2 | 3.3 | 4.0 |
| Hyphomicrobium rating (0–6)a | 2.4 | 2.0 | 4.6 |
| Clarification polymer concn (ppm) | 16.1 | 19.3 | 10.5 |
| Effluent total suspended solids (mg/liter) | 6.2 | 6.8 | 11.1 |
| Effluent STOC concn (mg/liter) | 24 | 24 | 27 |
| Aeration basin dissolved oxygen concn (mg/liter) | 1.5 | 1.8 | 1.7 |
| Sludge dewatering process | |||
| Waste activated-sludge concn (mg/liter) | 19,708 | 18,545 | 26,915 |
| Spin solids (% total solids) | 8.6 | 8.6 | 12.9 |
| Belt filter press cake solids (% total solids) | 10.5 | 10.3 | 13.3 |
| Cake production (dton/day) | 60.2 | 53.1 | 62.6 |
a
Microscopic rating scale based on that of Jenkins et al. (19): 0, none; 1, few; 2, some; 3, common; 4, very common; 5, abundant; and 6, excessive.
b
STOC, soluble total organic carbon.