Table 4 Seasonal changes in growth rates of azolla, nutrient 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 | 40.0 | 16 ± 6 | 2.4 ± 0.8 | 20.0 | 13.2 ± 4 | 0.68 ± 0.4 | 3.5 | 33.7 ± 10 |
15 | NA | NA | 6.1 ± 3 | 2.3 ± 0.7 | 4.1 ± 2 | 1.06 ± 0.5 | 2.1 | 12.3 ± 8 | |||
20 | 58.2 ± 8 | 2.9 ± 0.9 | 0.0 | 2.0 ± 0.9 | 0.0 | 1.0 ± 0.6 | 2 | 2.3 ± 0.5 | |||
April | 10 | NA | NA | 40.0 | 18.7 ± 8 | 2.1 ± 1.0 | 20.0 | 13.6 ± 4 | 0.64 ± 0.3 | 3.3 | 12.8 ± 4.8 |
15 | NA | NA | 4.5 ± 2 | 2.4 ± 0.7 | 8.5 ± 1 | 0.76 ± 0.3 | 3.1 | 0.5 ± 0.2 | |||
20 | 88.5 ± 18 | 4.4 ± 0.7 | 2.5 ± 1.1 | 1.9 ± 0.9 | 0.0 | 1.0 ± 0.6 | 1.9 | 0.0 | |||
June | 10 | NA | NA | 40.0 | 23.1 ± 6 | 1.7 ± 1.0 | 20.0 | 16.9 ± 5 | 0.31 ± 0.1 | 5.5 | 8.8 ± 1.8 |
15 | NA | NA | 10.1 ± 4 | 2.0 ± 1.1 | 10.1 ± 5 | 0.7 ± 0.2 | 3 | 3.9 ± 1.2 | |||
20 | 67.2 ± 6 | 3.3 ± 0.9 | 8.1 ± 3 | 1.5 ± 0.8 | 6.1 ± 3 | 0.7 ± 0.3 | 2.3 | 2.7 ± 1.2 |