Table 1.
Characteristics of analyzed WWTPs.
| WWTP ID | WWTP1 | WWTP2 | WWTP3 | WWTP4 | WWTP5 | WWTP6 | WWTP7 | WWTP8 | WWTP9 |
|---|---|---|---|---|---|---|---|---|---|
| WWTPs complex | LOS | LOS | LOS | LOS | LOS | LOS | KOS | KOS | KOS |
| Technology | SF | N-DN | UCT | UCT | UCT | UCT | CAS | UCT | UCT |
| WWTP capacity (103 m3/day) | 1000 | 500 | 80 | 80 | 80 | 500 | 1000 | 600 | 600 |
| Bioreactors hydraulic regime | Plug-flow | Plug-flow | Carrousel | Plug-flow | Carrousel | Carrousel | Plug-flow | Plug-flow | Plug-flow |
| Hydraulic retention time (h) | 12 | 12 | 9 | 9 | 9 | 12 | 8 | 10 | 10 |
| BOD –inflow (mg/L) | 180–190 | 180–190 | 180–190 | 180–190 | 180–190 | 170–190 | 90–130 | 80–120 | 90–130 |
| BOD –outflow (mg/L) | 3–4 | 2–3 | < 3 | < 3 | < 3 | 1–2 | 5–6 | 1–3 | 1–3 |
| COD –inflow (mg/L) | 500–550 | 500–550 | 500–550 | 500–550 | 500–550 | 450–500 | 310–350 | 300–340 | 310–350 |
| COD –outflow (mg/L)` | 30–40 | 30–40 | nd | nd | nd | 30–40 | 30–40 | 30–40 | 30–40 |
| N-NH4- inflow (mg/L) | 40–50 | 40–55 | 40–50 | 40–50 | 40–50 | 35–45 | 40–50 | 35–45 | 40–50 |
| N-NH4- outflow (mg/L) | 5–6 | 0.4–0,5 | < 0,4 | < 0,4 | < 0,4 | 0,3–0,4 | 12–16 | 0,3–0,5 | 0,3–0,5 |
| N-NO3 – outflow (mg/L) | 10–11 | 10–11 | < 9 | < 9 | < 9 | 7–8 | 5–9 | 8–9 | 8–9 |
| P-PO4 – inflow (mg/L) | 4–5 | 4–5 | 4–5 | 4–5 | 4–5 | 4–5 | 2–4 | 2–4 | 2–4 |
| P-PO4 – outflow (mg/L) | 2,5–3,5 | 3–4 | < 1 | < 1 | < 1 | 0,2–0,3 | 0,3–0,6 | 0,2–0,4 | 0,2–0,4 |