Energy-efficient wastewater treatment plant

Challenge

The city of Villach is developing into an ever larger industrial location due to the establishment of new companies as well as the expansion of existing companies. Among other things, this has had a significant impact on the local wastewater treatment plant, which had to be expanded in order to meet the special requirements of the nitrogen-rich wastewater from the semiconductor industry. This means that additional purification stages or technologies have been installed that are specifically designed to effectively remove the nitrogen from the wastewater. This is necessary in order to safeguard Villach as an industrial location in the long term.

As part of a bidding consortium, Wagner Consult was commissioned to implement newly developed technologies in the field of wastewater technology with a concept tailored to the Villach wastewater treatment plant.

Solution

Based on laboratory tests together with the local university, Wagner Consult has developed a concept with which industrial wastewater and municipal wastewater can be cleaned together without the need to add carbon from outside.

The efficient Triple A process (Alternating Activated Adsorption) was used, which removes a large amount of carbon and nitrogen at an early stage of wastewater treatment and relieves the main biology.

These processes enabled Wagner Consult to significantly increase the energy efficiency of the plant: fresh, energy-rich sewage sludge reaches the digester as quickly as possible, where sewage gas is produced. The increased gas production is used to generate electricity and heat, which covers the plant's entire energy requirements and enables the wastewater treatment plant to operate energy self-sufficiently.

The main biology of the wastewater treatment plant has been improved with the patented inDENSE technology, which compacts and stabilizes the sludge. The stabilization of the sludge properties reduces the load in the secondary clarification and increases the treatment capacity of the plant by 30% without the need to build additional tanks.

For additional relief of the main biology, the filtrate from the sludge dewatering is treated with Anammox bacteria using the DEMON process.

The new technologies were implemented in the existing plant while maintaining full operation.