Surface-flow Constructed Wetlands as Phosphorus Sinks From Agricultural Catchments

PhD defence, Thursday 28 June 2018, Lipe Renato Dantas Mendes.

2018.06.28 | Trine Berndt Turtiainen Scheelke

Lipe Renato Dantas Mendes

During his studies, Lipe Renato Dantas Mendes investigated phosphorus retention performance and the underlying processes in surface-flow constructed wetlands receiving agricultural drainage water. To achieve the goals, surface-flow constructed wetlands in Denmark with similar design, but receiving varying phosphorus loads and with different soil/sediments geochemical characteristics, were investigated. In addition, the influence of plant coverage on the stability of sediment-bound phosphorus was assessed. The study allowed a comprehensive understanding of how hydrological and biogeochemical factors control the retention and stability of phosphorus in the soil/sediments. Lipe R. D. Mendes demonstrated that phosphorus loading and the dominant phosphorus forms at the drainage discharge largely regulate the mass of phosphorus retained, while in situ phosphorus release and export may especially affect the percentage of phosphorus retained. Further, the supply of phosphorus sorbents and accumulation in the sediments increase the wetland capacity to retain phosphorus, while oxygen supply was suggested to prevent phosphorus release from the reducible iron-bound fraction across the sediment-water interface. The new research findings suggest a long-term potential of these surface-flow constructed wetlands as phosphorus sinks.

The PhD degree was completed at the Department of Agroecology, Science and Technology, Aarhus University.

This résumé was prepared by the PhD student.

Time: Thursday 28 June 2018 at 13:00
Place: Auditorium, Aarhus University Foulum, Blichers Allé 20, 8830 Tjele
Title of PhD thesis: Surface-flow constructed wetlands retaining phosphorus from agricultural drainage water
Contact information: Lipe Renato Dantas Mendes, e-mail: lipe.mendes@agro.au.dk, tel.: +45 8715 7413 – 2336 5942
Members of the assessment committee:
Dr. Dominik Zak, Department of Chemical Analytics and Biogeochemistry, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB, Germany
Associate Professor Kasper Reitzel, Department of Biology, University of Southern Denmark, Denmark
Professor Mathias Neumann Andersen (chair), Department of Agroecology, Aarhus University
Main supervisor:
Senior Scientist Charlotte Kjærgaard, Department of Agroecology, Aarhus University
Co-supervisor:
Senior Lecturer Karin Tonderski, Department of Physics, Chemistry and Biology, Linköping University, Sweden
Language: The PhD dissertation will be defended in English

The defence is public.
The PhD thesis is available for reading at the Graduate School of Science and Technology/GSST,
Ny Munkegade 120, building 1520, rooms 128-134, 8000 Aarhus C.

PhD defence
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Revised 29.06.2018