Table 1.
Treatment capacities and types of treatment processes employed in the WWTPs studieda
| Plant | Population served in 2010 | Avg flow (m3/day) | HRT (h) | SRT (days) | Treatment process |
|---|---|---|---|---|---|
| Activated sludge | |||||
| AS1 | 60,000 | 65,000 | 20 | 7 | Conventional activated sludge without primary settling |
| AS2 | 50,000 | 45,000 | 13 | 4–5 | Conventional activated sludge with primary settling |
| Physicochemical | |||||
| PC1 | 59, 000 | 44,000 | 2.69 | NA | Coagulation, with aluminum sulfate (alum) with organic polymer addition |
| PC2 | 280,000 | 240,000 | 1.87 | NA | Coagulation, with aluminum sulfate (alum) with organic polymer addition |
a
HRT, hydraulic retention time; SRT, solids retention time; NA, not applicable.