Table 2
Concentrations (mg L−1) of environment parameters (mean ± standard error) in INLET and the modified constructed wetlands (HCW, MHCW-1 and MHCW-2)
| Filters |  -N |  -N | TKN |  -P | TP | COD | BOD5 | TSS |
|---|---|---|---|---|---|---|---|---|
| INLET | 22.5 ± 1.2 | 41.1 ± 1.2 | 48.9 ± 3.3 | 2.4 ± 0.1 | 5.1 ± 0.4 | 185.4 ± 13.7 | 149.7 ± 14.6 | 26.8 ± 2.5 |
| HCW-1 | 8.2 ± 3.1** | 26.8 ± 1.2**** | 36.5 ± 2.5*** | 1.7 ± 0.2**** | 4.1 ± 0.3** | 42.2 ± 4.9**** | 95.6 ± 12.2**** | 6.4 ± 1.6**** |
| MHCW-1 | 8.6 ± 3.7** | 27.5 ± 1.0**** | 32.5 ± 3.4*** | 1.5 ± 0.1**** | 3.7 ± 0.3** | 41.9 ± 3.7**** | 68.7 ± 14.7**** | 6.5 ± 1.9**** |
| MHCW-2 | 8.1 ± 3.4** | 23.8 ± 1.3**** | 28.9 ± 2.8*** | 1.4 ± 0.1**** | 3.4 ± 0.3** | 39.1 ± 4.1**** | 43.1 ± 9.4**** | 5.3 ± 1.6**** |
| Vietnam's standarda | 10 | 50 | – | 10 | – | 150 | 50 | 100 |
| Filters | -N | -N | TKN | -P | TP | COD | BOD5 | TSS |
|---|---|---|---|---|---|---|---|---|
| INLET | 22.5 ± 1.2 | 41.1 ± 1.2 | 48.9 ± 3.3 | 2.4 ± 0.1 | 5.1 ± 0.4 | 185.4 ± 13.7 | 149.7 ± 14.6 | 26.8 ± 2.5 |
| HCW-1 | 8.2 ± 3.1** | 26.8 ± 1.2**** | 36.5 ± 2.5*** | 1.7 ± 0.2**** | 4.1 ± 0.3** | 42.2 ± 4.9**** | 95.6 ± 12.2**** | 6.4 ± 1.6**** |
| MHCW-1 | 8.6 ± 3.7** | 27.5 ± 1.0**** | 32.5 ± 3.4*** | 1.5 ± 0.1**** | 3.7 ± 0.3** | 41.9 ± 3.7**** | 68.7 ± 14.7**** | 6.5 ± 1.9**** |
| MHCW-2 | 8.1 ± 3.4** | 23.8 ± 1.3**** | 28.9 ± 2.8*** | 1.4 ± 0.1**** | 3.4 ± 0.3** | 39.1 ± 4.1**** | 43.1 ± 9.4**** | 5.3 ± 1.6**** |
| Vietnam's standarda | 10 | 50 | – | 10 | – | 150 | 50 | 100 |
Note: Asterisks indicate statistically significant differences between INLET and HCW and MHCWs (** for p < 0.01; *** for p < 0.001; **** for p < 0.0001).
aVietnam's technical regulation on domestic wastewater discharge quality (QCVN 40:2011/BTNMT). –: undefined.