Master Student/intern Working On Biological - Basel, Schweiz - Eawag

Eawag

Geprüftes Unternehmen

Basel, Schweiz

vor 2 Wochen

Geschrieben von:

Lena Schneider

beBee Recruiter

Beschreibung

Eawag, the Swiss Federal Institute of Aquatic Science and Technology, is an internationally networked aquatic research institute within the ETH Domain (Swiss Federal Institutes of Technology).

Eawag conducts research, education and expert consulting to achieve the dual goals of meeting direct human needs for water and maintaining the function and integrity of aquatic ecosystems.

The Department of Process Engineering has a vacancy for a

Master student/Intern working on biological wastewater treatment

Toward full Total Nitrogen (TN) removal in Aerobic Granular Sludge (AGS) systems operated in continuous-flow mode

Topic

A large fraction of Swiss wastewater treatment plants (WWTP) is reaching their maximum treatment/clarification capacities, resulting in operational problems such as incomplete nitrification.

It is therefore crucial to develop new technologies to upgrade existing WWTP and intensify their treatment capacities.

Aerobic granular sludge (AGS) represents a key advance for wastewater treatment processes (van Loosdrecht and Brdjanovic, 2014), and is presented as the main alternative to conventional activated sludge systems.

AGS systems are usually operated as sequencing batch reactors (SBR), where both microbial and physical selection mechanisms take place, leading to granulation.

But most of the existing WWTP are operated in continuous-flow (CF) mode, while the conversion of CF systems into SBR is very challenging.

A main challenge is therefore

to develop aerobic granules in systems operated in CF mode, where conditions in terms of microbial and hydraulic selection are not favourable.
Also, mass-transfer in AGS systems is limited by diffusion, resulting in the formation of concentration gradients within the granules. During the aerated phase, an oxygen gradient thus develops within the granules, whereby the outer layer is aerobic and the inner core is anoxic or anaerobic (de Kreuk et al., The formation of different redox conditions within the granules allow nitrification and denitrification to occur simultaneously (Winkler et al., But practical experience however indicates that SND is limited during the treatment of municipal WW with AGS systems (Layer et al., In theory, aeration could be fine-tuned to control the flow of organic substrates towards denitrification in order to maximize TN removal.

However, it is not clear how the aeration influences the fate of organic substrates (hydrolysis, fermentation, storage), their utilization by the different microbial communities and the denitrification and total nitrogen (TN) removal.

Another challenge is therefore

to better understand how to control aeration in order to in-crease SND and TN removal, without increasing green-house gas emissions such as

N2O

.

This project is a collaboration between two engineering firms (Hunzicker Betatech AG and ARA Consult) and two WWTP (WWTP of Gossau and Laufäcker).

Preferred starting date is as soon as possible.

Eawag is a modern employer and offers an excellent working environment where staff can contribute their strengths, experience and ways of thinking. We promote gender equality and are committed to staff diversity and inclusion. The compatibility of career and family is of central importance to us.

For further information, please contact Dr Nicolas Derlon.