F3 - Controlling of phosphorus fluxes in urban systems: Analogous processes in limnic sediments and sewage sludges
Doctoral student: Lena Heinrich 
Supervisors: Dr. Michael Hupfer , Prof. Dr. Matthias Barjenbruch 
Introduction / Background
The biogeochemical phosphorus (P) cycle has been altered dramatically and in a short time by human activities (Scholz et al., 2014), e. g. the mining of mineral P and the usage of P fertilizers in agriculture. Therefore, P is today an increasingly scarcer resource and, on the other hand, the main trigger for eutrophication of lakes and rivers.
In order to further minimize P discharge to water bodies and recover P from sewage sludges, it is crucial to understand biogeochemical P processing in WWTPs. In the often heavily managed urban lakes, the understanding of biogeochemical P cycling is fundamental to optimize managing measures. Profundal lake sediments and waste water treatment sludges can be considered resembling systems where hypothetically analogous transformation processes of P binding forms occur. Learning from both systems, lake sediments and sewage sludges, will allow a further insight regarding the impact of natural and technical interfaces on P fluxes in urban systems.
- Analogous transformation processes of P binding forms in profundal lake sediments and in municipal wastewater treatment using Fe-precipitation.
- © Heinrich
The project aims on studying analogous anaerobic processes at natural interfaces (lake sediments) and technical interfaces (WWTPs) which act as sinks in the urban P flow. The envisaged improved mechanistic understanding is to serve as a basis for quantitative modeling of P sinks in natural and technical interfaces. In the long term, the research will help to optimize management strategies in urban aquatic ecosystems by combining water protection with P recovery technologies.
The investigations will include process studies in an urban WWTP using iron precipitation for the removal of P and field studies in heavily managed urban lake systems. Complementary, laboratory experiments under defined conditions will allow the simulation of alternative management scenarios. Special emphasis will be given to the formation of Fe-P minerals. Analytical tools like X-ray absorption spectroscopy and XRD (X-ray diffractometry) for the detection of P forms will be applied.
Scholz, R., H. Roy, A., Hellums, D., Schipper, W., Langeveld, K., & Reller, A. (2014). Sustainable Phosphorus Management: A Transdisciplinary Challenge (pp. 191-212).
- Other UWI projects: H4, F1, S1 : Biogeochemical processes in natural and technical systems
- Common topics: Interfaces in urban freshwater ecosystems