E-VENT – Less Energy Consumption and CO2 Emissions of WWTPs

Evaluation of process options for the reduction of energy consumption and greenhouse gas emissions of Berlin sewage treatment plants

Berlin’s sewage treatment plants rank among the largest energy consumers within the municipal facilities. Corresponding energy efficiency measures have been implemented already, and the biogas resulting from the treatment process is used for electricity and heat production. Nevertheless, the average annual power consumption of Berlin’s six WWTPs exceeds 90,000 MWh which leads to a significant contribution to the associated greenhouse gas emissions (40,000 t CO2.eq/a).

The E-VENT project examines new process options contributing to an energy-related optimisation of Berlin’s WWTPs. One of the project’s major objectives is to analyse the eligible process options in view of their feasibility taking into account the specific operation conditions of the treatment plants in Berlin. The according tests are performed in close cooperation between Kompetenzzentrum Wasser and Berlin’s water utility Berliner Wasserbetriebe.

Alternative methods for nitrogen and carbon removal, as well as methods for increasing the biogas yield in sewage sludge treatment, are being tested. For the majority of the process options to be examined data from previous KWB projects are available which are to be transferred to the process conditions of large scale WWTPs.

In addition, experimental studies on laboratory and pilot scale are carried out. With regard to the granular sludge technology, it will be analysed whether and to what extent the generation of granulated biomass from Berlin wastewater water is possible at all. Furthermore, test series relating to the treatment of sewage sludge by thermo-chemical hydrolysis processes as well as thermal pressure hydrolysis are to be carried out in order to get a more reliable estimate of the process efficiency and risks associated to different compositions of sewage sludge.

The project is financed by the Berlin Programme for Sustainable Development (BENE) with funds from the European Regional Development Fund and the State of Berlin (funding code 1158-B5-0). In addition, Berliner Wasserbetriebe contribute to the project expenses.


© Header-Foto: Joachim Donath