Comprehensive modeling of mat density effect on duckweed (Lemna minor) growth under controlled eutrophication

The effect of mat density on duckweed (Lemna minor) growth was studied under controlled conditions: 12.5 h a day light exposure and 342 Mol m(-2) s(-1) light intensity at 20 degrees C. The plant growth was carried out in Hoagland medium for 7 days without harvesting. The results revealed a maximal biomass growth rate of 88 g-dry m(-2) (1470 g-wet m(-2)) at an optimal initial mat density of 45 g-dry m(-2) (750 g-wet m(-2)), with removal rates for nitrogen (N) and phosphor-us (P) of 483mg-N m(-2) d(-1) and 128mg-Pm(-2)d(-1), respectively. A mathematical model that takes into account the mat density was developed in order to simulate the growth of Lemna minor under controlled eutrophication. Based on experiments carried out, the model exhibits a reliability of 89%. The model remains to be validated at the full-scale level. (c) 2006 Elsevier Ltd. All rights reserved.