The denitrification process in water bodies, driven by microorganisms associated to the sediment, contribute to the self-purification of nitrates. This experiment will evaluate the use of leachates of aquatic plants as carbon sources for the microorganisms to increase their denitrifying activity. It is expected that the release of labile carbon from helophytes to a system already rich in nitrogen and phosphorous will generate a decrease of nitrates in the water, maximizing the effectiveness of the self-purification processes in residual waters without the need of any addition of external compounds.
To address this question we will produce leachates of two different species of aquatic plant with leaves contrasting in their nutrient qualities (Iris pseudachorus y Phragmites australis). Leachates will be inoculated in mesocosms containing sediments with biofilms from a WWTP-receiving streams. We will estimate denitrification rates based on the accumulation of N2O, an intermediate compound in denitrification.
Leading scientist: Joaquín Cochero, Researcher in the Instituto de Limnologia “Dr. A. Ringuelet” – CONICET – UNLP (Argentina).