- Sludge recovery, Wastewater
Aquantis: when wastewater generates energy for the Pays Voironnais
Commissioned in 1994, the Aquantis wastewater treatment plant was facing a steady rise in hydraulic and pollutant loads driven by the area’s growth. In 2023, the Pays Voironnais urban community entrusted Stereau with the Aquantis-Voreppe project, tasked with expanding the facility’s treatment capacity and strengthening its depollution performance, particularly for nitrogen, all while embedding the project in an ambitious energy transition approach.
The challenges
- Increase the treatment capacity of the Aquantis wastewater treatment plant to support the demographic and economic growth of the Pays Voironnais
- Meet new environmental requirements by strengthening treatment performance, particularly for nitrogen removal, to sustainably preserve the quality of water discharged into the Isère
- Turn sewage sludge into an energy resource through a complete anaerobic digestion and biomethane production line, injectable into the GRDF network
Our solutions
Stereau designed and carried out the expansion of the Aquantis wastewater treatment plant, combining enhanced treatment performance with energy recovery from sludge. The project is built around the addition of a primary settling stage, the optimization of biological treatment for nitrogen removal, and the modernization of existing equipment.
At the heart of the facility, a complete anaerobic digestion line converts sludge from wastewater treatment into biogas, which is then purified into biomethane and injected into the GRDF network. The system includes a 2,500 m³ digester, a 500 m³ gas holder, and a membrane purification unit, enabling the production of local renewable energy from the area’s own resources.
All the work was carried out while keeping the plant operational, ensuring continuous wastewater treatment throughout the entire project.
Benefits
Increased treatment capacity of the plant to sustainably meet the area’s needs, with capacity raised to 94,800 PE.
Local biomethane production from sewage sludge, contributing to the development of renewable energy and the ecological transition of the Pays Voironnais.
Improved treatment performance, particularly for nitrogen removal, for better preservation of the receiving natural environment.
Recovery of sludge from several wastewater treatment plants in the area, in line with a circular economy approach and the optimization of local resources.
Other achievements
