Master thesis

Topic Many wastewater treatment plants (WWTPs) in Switzerland are reaching their maximum treatment and clarification capacities, leading to occasional nitrification failures. With upcoming legislative changes and population growth, Swiss WWTPs will soon be required to treat higher nitrogen loads. Consequently, it is essential to develop advanced, intensified technologies to upgrade existing WWTPs with minimal modifications to their current treatment processes. Densified Activated Sludge (DAS) is defined as a mixture of flocs and small, dense granules (diameter < 500 microns). DAS offers significant advantages over conventional activated sludge, especially in intensifying nitrogen removal. In Switzerland, several full-scale WWTPs operate with DAS systems. While some plants have successfully achieved sludge densification, many have encountered challenges in converting flocs into small granules. The reasons behind successful or unsuccessful densification, however, remain unclear.The proposed master’s thesis/internship will focus on a comparative study of multiple full-scale DAS plants in Switzerland. The goal is to gain deeper insights into the factors affecting sludge densification, such as influent composition, growth and mass transport conditions in unaerated zones, as well as specific operational conditions and plant configurations. This project is a collaboration between Eawag and the Zurich WWTP. 
We are looking for a master student with interests in advanced technologies for biological wastewater treatment and in programming / data treatment The candidate should be able to communicate in English and (preferably) also in German. Preferred starting date: as soon as possible. 

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