Green All-Rounders - Large-scale experiment at the sewage treatment plant

Clean water and algae? For most people, this does not add up. Dr. Diana Reinecke-Levi (IBG-2) sees it differently. At the campus sewage treatment plant, she wants to find out how to filter nitrates, microplastics or traces of pharmaceuticals out of the water with microalgae.

She eats them as green muffins, drinks them as smoothies, collects them privately – and researches them at Jülich: “Algae are incredibly versatile,” says biotechnologist Dr. Diana Reinecke-Levi from IBG-2 excitedly. “From perpetual ice and rainforests to deserts, from salt water and garden ponds to house’s walls: in three and a half billion years of evolutionary history, algae have developed an incredible number of possibilities and solutions for survival!” The 40-year-old is convinced: “Algae can help us meet global challenges such as climate change and global food issues.” For two and a half years, she has been researching at IBG-2 how microalgae can be used even better in the bioeconomy – as a “green” raw material, for example.

Technology for the world: Dr. Diana Reinecke-Levi’s vision is an algae reactor that can be replicated anywhere for water purification.

The 40-metre experiment

Since last September, the algae expert has often been visiting the sewage treatment plant on the edge of the Jülich campus. There, the sewage and wastewater technology team (T-WK) purifies the domestic wastewater from Forschungszentrum Jülich in several stages before it may be discharged into the Rur again. Reinecke-Levi now uses one of the large holding basins at the wastewater treatment plant, with room for 700,000 litres of wastewater, for her science: together with T-WK and ZEA-1, she has added a huge algae reactor to it. “It is an algae-based water filter that makes the already pre-purified water even cleaner and enriches it with oxygen,” the researcher explains. “In simple terms, we built a 40-metre-long steel channel with a slight incline next to the basin and covered it with a net. 120 litres of wastewater are pumped over it per minute. Thanks to the sunlight and the nutrients in the water, wild algae grow on the net to form a thick film – comparable to a pebble in a river.”

The punch line: microalgae use nitrate and phosphate residues in the water to grow. “These are substances from agricultural fertilizer that also strongly pollute the groundwater,” says the researcher. “The algae process these substances to add them to their biomass, which can be scrubbed off and in turn used as fertilizer or as a renewable raw material.” The process is called Algal Turf Scrubber (ATS) and is being researched worldwide. In Jülich, it is already the fifth ATS prototype in three years. “But it’s the first of this magnitude,” Reinecke-Levi emphasizes. At Forschungszentrum Jülich’s wastewater treatment plant, she is now testing in practice how effectively the algae layer can be built up for water purification. “We do not have concrete data yet. However, we can already see that it is technically and biologically feasible!”

Transferring knowledge to the world

The researcher is already planning further, however: in the future, she wants to find out whether an algae reactor can also help to remove microplastics and pharmaceutical residues from the water. “Trace substances from pharmaceuticals such as antibiotics, antidepressants or ‘the pill’, for example, which enter the water cycle through urine and can have a negative impact on people and the environment.” The German wastewater guidelines do not yet specify uniform limits for these. “But in this way, our research can help prepare for future changes in the law.”

Reinecke-Levi is working closely with the infrastructure for her large-scale experiment. “The fact that we were able to provide a basin at all is ultimately a consequence of the corona pandemic,” explains Heinz Tirtey, T-WK team leader and head of the wastewater treatment plant. “Water consumption on campus has fallen sharply since, despite an increase in the number of employees.” This is the first large-scale experiment at Jülich in which the campus wastewater treatment plant is actively involved. Tirtey emphasizes, “We help research where we can!” Mechanical engineer Guido Offermanns from ZEA-1 also found this collaboration exciting: “Despite its enormous size, we had to design the algae reactor as simple as possible and deliberately used only materials that are cheap and available practically everywhere.” Reinecke-Levi’s goal is the transfer of knowledge: “It is intended that this type of algae reactor can be replicated all over the world – in regional agriculture as well as in developing countries.”

From Lusatia to Saudi Arabia

It was also the algae that opened the doors to the world for Diana Reinecke-Levi: having grown up in Saxony-Anhalt, she became interested in human genetics as a schoolgirl after the fall of the Berlin Wall and then trained as a medical-technical laboratory assistant after graduating from school in 1997. From 2000 to 2002, she worked in human genetics projects, for example to sequence the DNA of the Icelandic population or to detect certain hereditary diseases: “However, there was also a lot of suffering involved.” For the then only 20-year-old, this was reason enough to go new ways. She decided to study biotechnology at the Lausitz University of Applied Sciences: “This is where I started to work with algae,” says Reinecke-Levi. The tiny creatures have accompanied the researcher since then, bringing her from Lusatia to South Africa, Israel, the Netherlands, Saudi Arabia and finally back to Germany in the following 16 years. In addition to her algae research, she has also repeatedly worked as a consultant in the private sector. “Thanks to algae, I got to know very different countries, cultures and fields of application for these green all-rounders,” says Reinecke-Levi. She now lives in Jülich with her Israeli husband, researching there for the whole world.

Do it yourself!

Build your own algae reactor

Guido Offermanns and Werner Lesmeister from ZEA-1 have just the right thing for anyone who is good with their hands and fancies an exciting DIY project: instructions for building their own small algae reactor at home! The Jülich mechanical engineers reveal which tools and materials are needed – and which steps are required to assemble everything correctly.

Download PDF

“We deliberately tried to keep the experimental set-up simple and cheap, so that in the end practically anyone anywhere in the world can replicate it. Simple materials, which are also available in every DIY store, and a little craftsmanship are absolutely sufficient. At the same time, we used as many components as possible made from renewable raw materials – meaning wood instead of metal, wherever possible.”

Last Modified: 07.11.2023