One energy efficient solution for the processing of waste activated sludge (WAS) is to haul to a central WWTP and process filtrate through the aerobic process.
The challenge in making this a practical solution is the requirement for a reliable, low-maintenance water quality monitor that could accurately identify periods for supplemental organic loading.
The key question for United Utilities was could a bio-electrode sensor provide an in-situ reading directly from the primary clarifier and identify key periods of low organic loading to a central WWTP and gradually increase organic loading (WAS filtrate)?
For the installation the sensor was positioned in primary clarifier. This was located downstream of tie-in location of WAS filtrate addition.
The sensor generated an initial weekly organic Carbon consumption profile before any supplemental Carbon was added to the facility. Tues, Wed, Thurs mornings and weekend were highlighted as key windows for receiving additional Carbon.