Root and Shoot Biomass Growth of Constructed Floating Wetlands Plants in Saline Environments.

Constructed Floating Wetlands (CFWs) are increasingly being used globally in freshwater environments such as urban lakes and ponds to remove pollutants from urban stormwater runoff. However, to date there has been limited research into the use and performance of these systems in saline environments. This study compared the root and shoot biomass growth and nutrient uptake of five different plant species, , , , and , in three different saltwater treatments over a 12-week period. The aim of the study was to identify which of the plant species may be most suitable for use in CFWs in saline environments. Plant nutrient uptake testing revealed that had the greatest percentage increase (1473⁻2477%) of Nitrogen mass in the shoots in all treatments. also had impressive Nitrogen mass increase in saltwater showing an increase of 966% (0.208 ± 0.134 g). This suggests that the use of and plants in CFWs installed in saline water bodies, with regular harvesting of the shoot mass, may significantly reduce Nitrogen concentrations in the water. had the greatest percentage increase (112% or 0.018 ± 0.020 g) of Phosphorous mass in the shoots in the saltwater treatment. had the greatest percentage increase (315% or 0.026 ± 0.012 g) of Phosphorous mass in the roots in the saltwater treatment. This suggests that the use of and plants in CFWs installed in saline water bodies may significantly reduce Phosphorous concentrations in the water if there was a way to harvest both the shoots above and the roots below the CFWs. The study is continuing, and it is anticipated that more information will be available on CFW plants installed in saline environments in the near future.