Federal office of energy

Application of aerobic granules for wastewater treatment optimization: impact on the energy consumption and biological process improvement 


BlueWatt Engineering Sàrl is exploiting and developing a state of the art physicals models library for the numerical simulation of Waste Water Treatment Plants.

Puratis Sàrl is Swiss R&D company active in domain of environmatal biotechnology. Puratis develops and applies  novel wastewater treatment processes for complex organic compounds removal. 

  1. Integrating aerobic granular biomass with the existing activated sludge systems i.e. forming so-called “hybrid biology” – which aims to increase the biological system activity for nitrogen removal of non-nitrifying WWTPs . The expected reduction in energy consumption is 15%.

  2. The higher carbon compounds removal efficiency of the hybrid biological process will contribute to the additional 5% energy saving in an existing WWTP.

  3. The process development and process control will by supported and optimized by the integration of the development of an adapted mathematical model to be integrated in the existing modeling software package. 



  1. Validation of the effectiveness of the new biological hybrid system, combining activated sludge systems and granular biomass

  2. Measuring over a period of 10 month the efficiency of the biological treatment and the energy consumption.

  3. Operational data collection for process validation and control and integrating the data in the simulation software.

  4. Ecological and economical validation of the technology upgrade


04.06.2015KICK-OF meeting

29.05.2015Project approved



Media release 


D1.1. Obtained process and operational parameters for nitrogen removal from selected municipal wastewater 


D1.2. Developed mathematical model of aerobic granular process based on the obtained laboratory data 


Pilot plant installed in WWTP Orbe and ready to start (the first piloting period carried out in July-October 2015 in WWTP Broc)


D2.1. Obtained process and operational parameters at pilot plant 


D2.2. Comparative study of the activated sludge and hybrid system energy and process efficiency concerning the carbon and nitrogen removal


D3.1. Report on calibrated models based on available pilot plant data 


D3.2. Comparative study for evaluation of the proposed technology compared to main stream treatment  


01.05.2017Project deadline

01.05.2017FINAL REPORT

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