Valoriise®: Reimagining the Wastewater Treatment Plant of Tomorrow

In response to the challenges of decarbonization, energy transition, resource preservation, and the strengthened regulatory framework introduced by UWWTD 2.0, Stereau has developed Valoriise®, a new-generation wastewater treatment plant concept. Its name, an anagram of Lavoisier, embodies its core philosophy: “Nothing is lost, everything is transformed.”

Today, wastewater treatment plants consume significant amounts of energy to remove the carbon, nitrogen, and phosphorus present in wastewater. Valoriise aims to reverse this approach: instead of simply removing these elements, the project seeks to capture, transform, and recover them as valuable resources.

Three Pillars for Reimagining the Wastewater Treatment Plant Valoriise® is built around three complementary principles that redefine material and energy flows across the entire wastewater treatment plant.

Maximize Carbon Capture

First principle: recover organic carbon before it is oxidized in biological treatment tanks. Enhanced upstream capture of organic matter allows a larger share to be directed to anaerobic digestion and, consequently, biogas production, while reducing aeration requirements. Depending on the configurations studied, this approach can deliver up to a 70% reduction in energy consumption associated with aeration. Carbon is no longer viewed solely as a pollutant to be removed; it becomes an energy resource that can be recovered and valorized.

Recovering Nitrogen and Phosphorus

Second principle: regard nitrogen and phosphorus not only as substances to be removed, but as valuable resources to be recovered. Their extraction reduces the energy and chemical inputs required for treatment while creating new opportunities for resource recovery, particularly in agriculture. Valoriise therefore promotes the development of local resource loops, in line with the principles of the circular economy.

Maximizing Renewable Gas Production Through Biological Methanation

Third principle: maximize the energy potential of captured carbon. Anaerobic digestion already converts part of this organic matter into biogas. Valoriise goes a step further by integrating biological methanation, developed in partnership with Enosis. This process uses renewable hydrogen to convert the CO₂ contained in biogas into additional methane. Instead of being separated and released during biogas upgrading, the CO₂ itself becomes a valuable resource. By combining enhanced carbon capture, anaerobic digestion, and biological methanation, Valoriise® can, depending on the configurations considered, achieve up to a 150% increase in biogas production.

The strength of Valoriise® lies in the interdependence of these three pillars. Capturing more carbon reduces energy demand while increasing the amount of material available for biogas production. Recovering nitrogen and phosphorus reduces the resources required for their removal and enables their recovery. Finally, biological methanation converts more carbon into renewable gas.

From Wastewater Treatment Plant to Resource Recovery Hub

Beyond its primary role of treating wastewater and protecting natural environments, a wastewater treatment plant can become a true local resource recovery hub. Depending on local needs and site-specific conditions, it can help produce and recover reclaimed water, biomethane, heat, electricity, and nutrients. Biological methanation also creates a link between water infrastructure and energy systems: renewable electricity can be converted into renewable gas through hydrogen production, providing an energy carrier that is easier to store and valorize.

An Approach Developed and Tested at Demonstration Scale Valoriise® builds on several ongoing R&D programs and demonstration projects that validate the different technological building blocks: carbon capture and sludge management in Saumur, a biological methanation pilot with Enosis in Liffré, research conducted with INRAE on the La Feyssine platform in Lyon, and trials focused on nitrogen and phosphorus recovery in the Netherlands. These pilot projects are gradually enabling the transition from technology validation to their integration within a comprehensive wastewater treatment plant architecture.

Preparing Wastewater Treatment for Tomorrow With the Urban Wastewater Treatment Directive (UWWTD) currently being transposed across EU Member States, the strengthening of decarbonization targets, rising energy costs, and the need to better preserve natural resources, local authorities must now rethink their wastewater management models. With Valoriise®, Stereau proposes a new approach: to turn the wastewater treatment plant from a facility dedicated solely to treatment into a key player in the circular economy and the energy transition of local communities. Treating water remains its primary mission. Valoriise also gives it the ability to preserve, produce, and recover the valuable resources it contains.