Effects of nutrients (P and N) on tolerance and root morphometry of Typha domingensis pers. in floating wetland systems

MUFARREGE, M.M.; DI LUCA, G.A.; HADAD, H.R.; MAINE, M.A.; CARRERAS, A.A.; CAMPAGNOLI, M.A.; NOCETTI, E.

Viena

Simposio; 9th International Symposium on Wetland Pollutant Dynamics and Control, WETPOL 2021; 2021

University of Natural Resources and Life Sciences (BOKU)

The aims of this work were to evaluate the effect of P and N on the tolerance and root morphometry of Typha domingensis plants and its implication in the removal efficiency in a floating treatment wetland (FTW). Plants, sediment and water were collected from an unpolluted pond near Santa Fe city, Argentina. The plants were pruned for their transport to the greenhouse. Plastic reactors (70 L) contained 4 Kg of sediment and 38 L of pond water were installed outdoors under a semi-transparent plastic roof. FTW consist in a plastic net and had a surface area of 0.10 m2. Buoyancy was provided by a PVC frame. Each raft had a total of 4 plants. The rafts were designed to allow roots (hanging in the water column) and rhizomes remain in the water while aerial parts emerge. After plant acclimatization, 38 L of the synthetic effluent containing 10 mg L-1 N + 2 mg L-1 P added as NH4NO3 and KH2PO4 in the reactors as follow: 3 reactors with FTW (A: with FTW and contaminant addition); 3 reactors without FTW (B: without FTW, with contaminant addition); 3 reactors Biological Controls (BC: with FTW, without contaminant addition) and 3 reactors Chemical Control (CC: without WTF nor contaminant addition). During the experiment, three synthetic effluent dumps were made. The experiment lasted 70 days. Chlorophyll a concentration was determined at the beginning and the end of the experiment. For the study of the internal morphology of roots; segments close to the base of the roots were extracted. The cross-sectional areas of roots, steel and the metaxylematic vessels were measured, and the number of vessels was counted.SRP, TP, N-NH4+ and N-NO3- were efficiently removed from water during the experiment. The removals of SRP and TP were significantly higher in the reactors A than the reactors B. N-NH4+, were not significantly different between reactors A and B, while N-NO3- removal from water was higher in the reactors A than in the reactors B. At the end of the experiment, the chlorophyll concentration, the aerial and submerged (roots and rhizomes) biomass increased significantly in the reactors A. TP concentrations were not different between rhizomes and leaves, while the lowest concentrations were observed in roots. The TKN in tissues was significantly higher in roots and rhizomes than in aerial parts. The concentrations of TP and TKN in the sediment did not show differences between the different reactors throughout the experiment. In the plants exposed to the experimental solution, the internal and external morphology of the root varied. Plasticity morphology is an important mechanism for the plant to acquire nutrients. The concentrations of TP and TKN in the sediment did not show differences between the different reactors throughout the experiment. The results show that the use of FTW is a promising strategy for the sustainable treatment of water bodies.