Agricultural and Biological Research

Investigation of the effectiveness of aquatic plants in filtering contaminated water

Helena Moreira* and Ginette Ross

Population increase and rapid urbanization are two major factors for scarcity of clean water in 21st century societies across the world. Modern sewage water treatment plants and filtration systems require a lot of economic and land resources which many “lesser developed countries” do not have, leading to large amounts of raw sewage water being released into the environment and a lack of clean water for millions. To fulfill such water demand, the use of aquatic plants, also known as macrophytes, have been used in a constructed wetland which allows for the filtration of contaminated water using natural processes involving wetland vegetation, soils, and their associated microbial assemblages. In the present study, Typha (cattail) and Pontederia crassipes (water hyacinth) have been tested in a simulated constructed wetland to study their effect on pollutants removal efficiency (nitrates, ammonium, pH, and dissolved oxygen). Results show that both the Typha and Pontederia crassipes were effective in filtering out the aforementioned contaminants through the process of phytoaccumulation. However, there was no clear correlation between dissolved oxygen levels and time in contact with the macrophyte roots possibly due to environmental factors. A better quantitative understanding of the phytoaccumulation process, such as the limits and plateau points of contaminant uptake is needed to optimize the usage and application of Typha and Pontederia crassipes in practical constructed wetlands.