Table 3 Seasonal changes in growth rates of duckweed, nutrients removals and chlorophyll concentration in synthetic wastewater
Months | Days from start | Growth density, g dw/m2 | Growth rate, g dw/m2-day | NH4-N initial, mg/l | NH4-N final, mg/l | NH4-N uptake rate, mg/l-day | PO4-P initial, mg/l | PO4-P final, mg/L | PO4-P uptake rate, mg/l-day | N/P uptake | Chl A + B, μg/ml |
|---|---|---|---|---|---|---|---|---|---|---|---|
January | 10 | NA | NA | 250.0 | 166.1 ± 18 | 8.4 ± 4 | 30.0 | 20.7 ± 6 | 0.93 ± 0.14 | 9 | 45.7 ± 12 |
15 | NA | NA | 46.2 ± 8 | 13.5 ± 6 | 8.9 ± 4 | 1.4 ± 0.9 | 9.6 | 19.3 ± 8 | |||
20 | 42.5 ± 10 | 2.1 ± 0.9 | 0.0 | 12.5 ± 7 | 3.9 ± 2 | 1.3 ± 0.7 | 9.5 | 12.3 ± 6 | |||
April | 10 | NA | NA | 250.0 | 176.7 ± 29 | 7.3 ± 3 | 30.0 | 20.6 ± 8 | 0.9 ± 0.4 | 7.8 | 15.8 ± 5 |
15 | NA | NA | 77.1 ± 11 | 11.5 ± 3 | 12.6 ± 6 | 1.20 ± 0.9 | 9.9 | 7.5 ± 3 | |||
20 | 71.1 ± 16 | 3.5 ± 0.9 | 37.1 ± 7 | 10.6 ± 4 | 10.6 ± 3.0 | 0.9 ± 0.4 | 10.9 | 2.5 ± 1.2 | |||
June | 10 | NA | NA | 250.0 | 221.1 ± 30 | 2.8 ± 2 | 30.0 | 26.9 ± 11 | 0.31 ± 0.2 | 9.3 | 5.8 ± 2 |
15 | NA | NA | 128.1 ± 28 | 8.1 ± 4 | 17.1 ± 8 | 0.86 ± 0.2 | 9.4 | 4.9 ± 2 | |||
20 | 45.8 ± 9 | 2.3 ± 0.7 | 98.1 ± 11 | 7.5 ± 3 | 13.1 ± 6 | 0.845 ± 0.2 | 8.9 | 2.9 ± 1 |