Comparison of three plants in a surface flow constructed wetland treating eutrophic water in a Mediterranean climate

Autores UPV


The goal of this study is to examine the suitability of three plants, Typha spp., Phragmites spp. and Iris pseudacorus, in a free-water surface constructed wetland created to treat eutrophic water from Lake Albufera (Valencia, Spain), a wetland of international importance. The growth, coverage and nutrient content of the three plants were studied, and chemical analyses were performed according to standard methods. The maximum standing crops measured for each plant were 1.9, 18.2 and 3.3 kg m-2, respectively, and their average nutrient concentrations were 2.1, 1.2 and 1.7 g P kg-1 and 12.1, 11.7 and 10.1 g N kg-1, respectively. A multiple harvest of Iris pseudacorus revealed that the removal of nutrients could be increased up to 50% for N and 100% for P compared with a single harvest. Biomass decomposition assays showed high values for five-day biochemical oxygen demand (115¿207 mg O2 g-1, depending on the plant and its age) and a substantial release of phosphorus, up to 100% of that contained in the biomass, highlighting the need to remove the litter fall.