Keywords: agricultural runoff, plants, nitrogen treatment, evapotranspiration, self–design, vegetated treatment systems, nutrient removal, constructed wetlands, inorganic nutrients, plant communities, wastewater treatment
Impact of plant assemblages on nutrient removal in constructed wetlands
Four different mesocosm scale constructed wetlands - monoculture (Carexstipata), self–designed (passive) community, mixed planted monoculture–passive community and a non–vegetated control - were compared to assess the effects of plant community composition on the removal of inorganic nutrients from agricultural runoff (synthetic tile water). The mixed and self–designed systems consistently produced effluent NO3–N concentrations significantly below 10 mg/L, and had higher rates of evapotranspiration. Results indicate the type and composition of the plant community can impact the performance of constructed wetlands. Therefore, self–design of the plant community through the existing seed bank may increase the effectiveness of wetlands in treating agricultural runoff.