Characteristic Analysis of Plants for the Removal of Nutrients from a Constructed Wetland using Reclaimed Water

One of the main issues with the East Route (ER) of the South-to-North Water Transfer Project (SNWTP) in China is water pollution. The Pingyin wetland, situated near the SNWTP, collects reclaimed water discharging from a sewage treatment plant. Selected aquatic plants were cultivated in the constructed wetland and their biomass, total nitrogen (TN) and total phosphorus (TP) contents and accumulation were studied to assess whether the selected plants were suitable for cultivation in the reclaimed water environment and to determine their nutrient removal rates. Most of the introduced species showed high vitality after 60 days growth, and plant biomass increased greatly from the early to the middle part of the growing season. The TN content for different plant species during the growing season varied from 30-165 mg/g, while the TP contents varied from 5-35 mg/g. The TN and TP contents of the introduced species were significantly higher than those of the local species. The main TN absorption organ was the plant leaves. The nutrient accumulation by the local species was significantly higher than that of the main introduced species since accumulation is determined mainly by the species biomass. The TN and TP removal of plants contributed 9.66% and 49%, respectively, to total nutrient removal in the constructed wetland.