Water resource recovery facilities (WRRFs) are facing increasing pressure to meet strict nutrient limits while also reducing energy use, carbon emissions, and supplemental chemicals—all within a constrained footprint. To help WRRFs tackle these challenges, our Water Office of Research, Innovation and Technology (ORIT) team is advancing new approaches on how to intensify treatment processes and deliver smarter, more sustainable solutions for utilities everywhere.
For example, we are testing new ways to remove nutrients from wastewater under real operating conditions using a 400‑gallon (1,514-litre) pilot treatment system—designed for a nominal flow of 0.6 gallons (2.3 litres) per minute—at the Boulder WRRF in Colorado. The system is modular and allows our researchers to compare different treatment approaches. This includes studying advanced aeration methods—such as running tanks at low dissolved oxygen (DO) or adjusting aeration based on ammonia levels—that use less energy and can support sustainable nutrient‑removal processes like simultaneous nitrification-denitrification (SND) and partial denitrification anammox (PdNA).
To boost treatment performance and make the system more resilient, our team is also evaluating the integration of a mobile media biofilm technology with the low-oxygen aeration strategies. Grown on small moving carriers, even in low‑oxygen, low‑mixing environments, these biofilms add treatment capacity without overloading clarifiers and help maintain important bacteria during cold weather or sudden high‑strength flows. When combined with low‑oxygen operation, they are expected to further strengthen SND and PdNA processes.
The pilot system is equipped with a full suite of online sensors that continuously measure ammonia, nitrate, DO, oxidation-reduction potential (ORP), and pH to support real‑time monitoring and testing of control strategies. These data streams also enable research into how machine learning and AI can improve digital monitoring and advance predictive control for future treatment optimization.
An important first step in developing and de-risking full-scale applications, pilot studies are a practical way to test, refine, and scale solutions to create customized, sustainable roadmaps.
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