13 Million Euro Order Received for Key Components of New Sludge Plant at Main Vienna Wastewater Treatment Facility

Vienna’s main wastewater treatment plant is to undergo comprehensive modernisation and expansion in tandem with an energy technology paradigmatic change, as the facility is to be converted from the city’s largest, municipal energy consumer into an eco-power plant. To date, operations at the facility consumed roughly one per cent of the city’s total electricity requirement, but now the E_OS energy-optimised, sludge treatment project is to make the plant energy-independent by means of the latest technology. Consequently, as an international specialist for energy-efficient wastewater and sludge treatment plants, WABAG (Austria) has been commissioned with the supply of key components for sludge digestion and the hot water boiler plant. The foundation stone for the E_OS project was laid on April 13th 2015.    

VA TECH WABAG GmbH in Vienna possesses comprehensive international experience in the handling of the sewage sludge emanating as a residue from biological wastewater treatment. Depending on the size of the treatment plant, enormous volumes of sludge can result, which have to be dealt with and disposed of appropriately. The most advantageous solution from an ecological and economic standpoint is anaerobic stabilisation in combination with the simultaneous use of the biogas generated during the controlled digestion of the sewage sludge in bioreactors. This gas is combustible and once turned into electricity can guarantee the independent supply of the wastewater treatment plant with power and part of its heating requirements.  

Six digester towers with a total capacity of 75,000 m3 are to be added to Vienna’s main wastewater treatment plant, which with a capacity of  400,000  m3/d is one of the very largest of its type. These imposing structures will have a height of 30m and WABAG is to supply the technical equipment for the digesters including the related peripherals and the biogas line. In addition, the Viennese specialists have also been awarded the hot water boiler plant lot. Within the scope of this contract, WABAG will be responsible for the detailed engineering, supply, installation and commissioning. The works are to be carried out while the plant remains in operation and will take a total of five years.

Since 2000, WABAG has designed and built forty anaerobic sludge treatment plants in countries as diverse as China, Turkey, Algeria and Iran. If the volume of all bioreactors is added to this figure, a total of around 500,000 m3 results. The majority of these facilities are equipped with energy recovery systems and in combination generate more than 25 MW of electricity, which for example would be sufficient to supply the town of Innsbruck in Austria with its population of 120,000.  

Wolfgang Miksa, the Managing Director of VA TECH WABAG GmbH in Vienna : “For us, this contract is very special as we have been able to continue our highly successful cooperation with the ebswien company. Naturally enough, we are also delighted to have captured an order on our doorstep and be able to contribute to the city in which we live and work.” 

The last joint project related to the extension  of the Vienna wastewater plant in 2005. WABAG employed the Hybrid™ process developed in conjunction with Prof.  Dr. Matsché for the design and supplied the prominent 15 second clarifiers.