Reuse-Brew: Demonstration of direct potable reuse for beverage production
The resource water is not everywhere available in sufficient quantity and quality. In addition, in many places, the existing water sources are increasingly under stress due to increasing urbanization, climate change, agricultural and industrial activities. These challenges are forcing many water suppliers and consumers to tap new but also unconventional water resources. One potential source is municipal wastewater, which, usually requires intensive treatment before reuse. On the other hand, municipal wastewater usually occurs close to the actual water demand and, is mostly independent of seasonal fluctuations.
The aim and motivation of this project were 1) to demonstrate the feasibility of wastewater reuse with established technologies but also with new approaches, 2) to educate the public about water scarcity and wastewater reuse, 3) to present the current research and development work as well as available technology solutions. In order to attract more attention but also to demonstrate the actual quality of the purified wastewater, it was utilized to brew our own beer (Reuse Brew). Following conventional treatment processes, 1) a biological denitrification, 2) a sequential biofiltration, 3) a membrane filtration and 4) a more advanced UV oxidation treatment (UV-AOP) were applied. Finally, 4 000 L of treated water that conformed to the German drinking water ordinance could be handed over to the Chair of Brewing and Beverage Technology (TUM), where it was refined to a Bavarian pale lager (800 L).
Figure: Water samples of the different treatment steps as well as the finished beer. From left to right: raw wastewater, wastewater treatment plant effluent, sequential biofiltration, membrane filtration (nanofiltration), advanced oxidation process with UV-radiation and H2O2 (UV-AOP).
The project is a collaboration between Xylem Services GmbH and the Technical University of Munich (TUM). Together with the Xylem Services GmbH, the Chair of Urban Water Systems Engineering at TUM realized the treatment of the wastewater into drinking water. The final brewing of the beer was carried out by the Chair of Brewing and Beverage Technology (TUM).
This video contribution with Prof. Dr.-Ing. E. Drewes delivers more information and an insight into the Reuse-Brew Project.