The efficiency of sewage treatment plants is crucial for municipal environmental goals, as they are major energy consumers and CO2 emitters. Sewage sludge contains valuable phosphorus, but it is difficult to access. Microbiological approaches offer potential to solve these problems by using specialized bacterial cultures to simplify phosphorus recovery and increase biogas production. However, these bacteria in sewage sludge cannot currently be reliably controlled. The ZUMISPEK project is developing a new approach with specifically tailored bacterial strains and a reactor technology. This enables the controlled breeding and sludge inoculation of the microorganisms based on monitored system states. This leads to stable, phosphorus-binding and energy-optimized material turnover, increases the phosphorus yield without precipitants and significantly reduces external power requirements and the amount of sewage sludge to be disposed of. The project aims to select different biomasses for biological phosphorus removal and reducing sewage sludge quantities. The bacterial strains are isolated from wastewater and sewage sludge and characterized using NGS. In vitro tests for P removal and sludge reduction are then carried out. The University of Stuttgart is verifying the function of the isolated strains in semi-technical systems under realistic conditions.
Since these bacterial strains occur in wastewater but are not stable, the main process must be continuously inoculated. The inoculation sludge is cultivated in separate bioreactors. This decentralized biomass production avoids complex processing and transport steps as well as emissions. Our software controls the cultivation of the biomass based on sensor data from the bioreactors and the sewage treatment plant and determines the optimal time and dosage for inoculation.