In this study, three wetland plant species (phragmites australis, typha and rush) were planted in separate cells to evaluate the proportion of total nitrogen (TN) and total phosphorus (TP) removal attributed to storage in plants. Four cells were considered for each plant to be tested in a completely randomised design having four replications. Results show that the uptakes of nutrients by rush, common reed and typha from the pilot system were 49.39% TKN; 17.98% P, 44.62% TKN; 13.22% P and 27.62% TKN; 9.46% P, respectively. The nutrient uptakes efficiency corresponding to common reed and typha were higher in above-ground compared to that of below-grounds; however, for rush, the nutrient uptake efficiency was higher in below-ground rather than in above-ground tissues. The results can be applied in plant species selection in the design of constructed wetlands in Isfahan as well as in optimising the performance of these systems.
Keywords: constructed wetland, wetland plants, nutrient removal, nitrogen, phosphorus