Holistic aeration management trial shows how operational optimisation can deliver rapid emissions and energy savings.
N₂O is a greenhouse gas around 275 times more potent than CO₂, accounting for up to 80% of wastewater treatment plant emissions. In France, N₂O reduction is led by wastewater authorities, driven by national climate targets and the Urban Wastewater Treatment Directive. Controlling these emissions is becoming increasingly important for French utilities as net zero and nutrient removal requirements emerge.
Cobalt Water’s N2ORisk decision-support platform offers a route to achieve this. The platform combines expert process knowledge with machine-learning models to quantify N₂O emissions in real time. The platform also supports operational optimisation to reduce both emissions and energy use.
Trial Reservoirs Initiative supported a trial to evaluate this technology under real-world conditions at Rennes Métropole’s Beaurade wastewater treatment plant. The project brought together Purecontrol (real-time aeration control), Cobalt Water Global (N2ORisk DSS), and Rennes Métropole (end user).
The objective was to validate the combined decision-support and real-time control approach for measuring, monitoring, and mitigating N₂O emissions.
The trial achieved approximately 20% electricity savings and avoided nearly 25,000 tonnes of CO₂e. By linking operational parameters, including dissolved oxygen levels, to N₂O risk, the system enabled targeted mitigation strategies without infrastructure changes. Following its successful demonstration at Beaurade WWTP, the technology moved to commercial use across four additional sites.
Vantaggi dell'innovazione
- Science-based quantification: Cobalt Water’s N2ORisk DSS platform replaced generic emission factors with precise estimates based on site-specific operational data.
- Real-time optimisation: Purecontrol’s AI platform enables dynamic aeration adjustments that reduce energy use while minimising N₂O formation risk.
- Cost effective mitigation: The system identifies low-cost operational strategies that reduce emissions without requiring infrastructural upgrades.
Servizi specialistici coinvolti
- Expert support: We provide expert support in trial design, execution and final documentation review to ensure high quality outcomes. This supports trial success for the end-user while serving as a good reference for the technology supplier in similar applications.
- Convalida della prova: Riceviamo e valutiamo il rapporto di fine sperimentazione dal fornitore della tecnologia. Il Serbatoi di prova affronta in modo specifico le domande chiave a cui il processo deve rispondere.
- Due diligence: Isle dispone di un solido processo per aiutare le parti interessate ad adottare tecnologie innovative e garantire che siano adatte allo scopo.
- Repayable grant funding: Isle facilita la negoziazione con gli sviluppatori di tecnologie e gli utenti finali per concordare i fattori critici di successo delle prove e gli indicatori chiave di prestazione (KPI). I prestiti vengono quindi erogati agli sviluppatori di tecnologie.
- Zero risk trial: Se una sperimentazione non raggiunge i suoi KPI, l'azienda tecnologica non è obbligata a restituire il prestito. Allo stesso modo, l'utente finale non ha l'obbligo di effettuare un ordine di acquisto; il serbatoio di prova si assume il rischio.
- Investor introductions: Isle utilizza la sua vasta rete mondiale per fornire introduzioni a potenziali investitori.
Risultati
The trial at Beaurade was a success, delivering significant measurable outcomes, including:
- Energy savings: Approximately 20% reduction in electricity use.
- CO₂e reduction: Nearly 25,000 tonnes of CO₂ equivalent avoided during the trial.
- Operational optimisation for N₂O reduction: Real-time N₂O monitoring and automated aeration optimisation linked operating conditions to emissions risk. This allowed operators to implement low-cost adjustments that reduce emissions without new infrastructure.
These results demonstrated that systematic N₂O reduction is achievable through intelligent process optimisation, offering a replicable model for other water utilities facing similar decarbonisation targets.
Contatto chiave:
For enquiries and further information, please contact Dr Jo Burgess, Head of Trial Reservoirs Initiative at [email protected].