摘要:We studied the nutrition removal, taxa and density of phytoplankton, concentration of chlorophyll-a (chl-a) of the monoculture constructed wetlands (CWs) planted with submerged macrophytes Hydrilla verticillata, Elodea nuttallii, Myriophyllum spicatum and Vallisneria natans to probe the nutrient and alga removal effects of the CWs. The CWs had significant differences (P < 0.01) in removing different nutrients, with E. nuttallii wetland having the highest removal rate of total phosphorus (TP), H. verticillata wetland having the highest removal rate of ammonia nitrogen (NH4-N) and M. spicatum wetland having the highest removal rate of chemical oxygen demand (CODCr). Removal rates of all the nutrients except CODCr changed obviously with seasons. The concentrations of chl-a and the density of phytoplankton in the CWs also varied with seasons, with the values being significantly lower in winter than in summer (P < 0.01). E. nuttallii wetland had a significantly lower chl-a concentration than the other wetlands (P < 0.01). Macrophyte biomass was significantly different among these wetlands (P < 0.01). E. nuttallii wetland had higher inhibition ability on algae than the other three wetlands in summer (P < 0.05), and E. nuttallii and M. spicatum wetlands than H. verticillata and V. natans wetlands in winter (P < 0.05).
关键词:Constructed WetlandsSubmerged PlantBiomassNutrient RemovalAlga Density