The students of the Masters Applied Ecohydrology At the beginning of the summer semester, they received four topics from their professors from the departments Construction and Applied Natural Sciences provided to the TH Lübeck: river renaturation, wastewater management, algae and nutrient balance of lakes. After theoretical introductions to the topics, the master’s students determined scientific questions and went on excursions to the southeast of Schleswig-Holstein.
Natural rivers: a comparison around the globe
Under the guidance of Prof. Dr. Edgar Nehlsen compared Deepshikha Srivastava and Nafisa Jaffar strategies for the renaturation of rivers in Germany and Asia. The students discovered that small rivers have so far been underrepresented in observations. The students also showed that natural aquatic design in Europe focuses on ecological restoration with advanced technologies and legal frameworks, while in South Asia the focus is on community participation and practical approaches. This highlights the opportunities for mutual learning and collaboration to improve sustainable water management.
Cecília María Hernández Castro, Mavzuna Azizova and Megan Rossouw took a closer look at how rivers are designed in Germany and China. To do this, the students compared two river restoration projects in Bad Schwartau and Yangtze based on a literature research. They discovered that the renaturation of the Schwartau was focused on landscape modifications and eco-hydrological improvements. The Yangtze project is based on technological approaches such as the reconstruction of river banks using concrete, gravel and sand.
Challenges in wastewater management
Dr.-Ing. Kai Wellbrock supervised the second group of students. Daryl Lloyd Cortez, Manisha Lohana and Sara Ajri presented the latest developments in wastewater treatment to their fellow students. This includes, for example, ozonation. Ozone is used to disinfect water because it effectively breaks down germs in the water. In pilot projects, the concentration of persistent and mobile substances was reduced by up to 50%. However, large-scale ozonation is still very expensive.
Renewable energy from feces
Daniel Uzoh, Esi Seguwa Chukwufunanya Yawson and Suebat Oluwakemi Mustapha presented a decentralized wastewater treatment system in Hamburg. In the Residential area “Jenfelder Au” In Hamburg, a new type of water cycle is being tested on a large scale for the first time. In addition to rainwater and wastewater from the toilet, the so-called black water, gray water from the kitchen, bathroom and washing machine is also collected and treated. The feces are fed via a negative pressure system into a biogas plant that generates green electricity and thermal energy.
Algae research: From water to value creation
Prof. Dr. Norbert Reintjes supervised a group of students who were working on algae. Victor Cesar Carneiro Silva and Mohammed Parvez analyzed the dynamics of cyanobacteria blooms – also called blue-green bacteria – and the factors that lead to toxic blooms. These include higher temperatures and a higher growth rate. The students made it clear that high light availability, high nutrient availability and long flowering duration are critical factors. What helps now? Silva and Parvez explained a method that uses ultrasound to prevent flowering before it occurs.
Luke Tomlinson, Sonam Yangkee Phurba and Yomali S. Dona took a closer look at mycosporin-like amino acids (MAAs). These are polyphenolic and bioactive compounds, of which there are around 30. Algae and cyanobacteria produce MAAs as UV protection. They can be obtained from the “umbilical purple tang,” which is a type of red algae. The students showed how the MAAs can be “harvested”. They compared the methods in terms of efficiency, scalability and cost.
Nutrient balance of lakes: challenges and solutions
David Guaña, Shreya Pataankar and Stina Nagavci examined the destruction of wetlands using the Schaalsee region as an example. In the Schaalsee region there are significant land use compartments formed by moors and fens. 72% of the area was drained, peat was mined for many years, and the water was diverted to the Farchau power plant. This led to a loss of groundwater levels and disruption of natural hydrology due to changes in water balance. How can the areas be rewetted? 1. Closure of drainage ditches and dams, 2. Restoration of rivers. 1500 hectares of moorland have already been restored.
Gabriella Speca, Htun Thiri Naing and Sovandara Bin highlighted the nutrient flows in groundwater lakes and the measures to reduce nutrient inputs. Rewetting projects in the Schaalsee region showed positive effects on reducing algae blooms.
Rafaela Schramm, Prof. Dr. Edgar Nehlsen, Dr. Kai Wellbrock, Prof. Dr. Norbert Reintjes, Prof. Dr. Christoph Külls, Dr. Ozgur Kisi and Prof. Dr. Philipp Wilfert from the Department of Civil Engineering and Applied Natural Sciences organized the conference.