United Utilities (U.K.) optimization of activated sludge process (ASP) - Case Study
United Utilities uses the SENTRY monitoring platform to optimize loading capacity and energy efficiency of the Activated Sludge Process. 'SENTRY is quick and easy to install and boasts an intuitive dashboard to display it's graphical representation of real-time data. This has provided us with a whole new level of insight into our site performance, which our graduate team are utilising to study efficiencies in our activated sludge process.'
sensors were installed at key influent and aerobic basin locations with real-time data going to a web-based dashboard with three key findings:
The treatment facility is able to handle the additional organic load received from other treatment facilities. The sludge centrate increased microbial activity (as measured by MET) in the wastewater prior to ASP but has had modest impact on MET in the ASP effluent. Organic loading continues to be increased gradually while SENTRY Microbial Electron Transfer (MET) alerts provide operations real-time monitoring of performance.
Large precipitation greatly reduces influent microbial performance. This is due to infiltration and inflow into the collection system reducing organic strength. The ASP effluent is largely unimpacted by the events recorded to date, suggesting the system has ample retention time and good hydraulic characteristics.
MET readings are shown to correlate to dissolved oxygen, providing a reliable, robust measure of aeration efficiency. A pattern between dissolved oxygen and MET is demonstrated, with increasing MET corresponding to falling dissolved oxygen concentrations and decreases in MET resulting in rapid increases in dissolved oxygen. This is interpreted as higher MET representing periods of higher biological action that rapidly consumes dissolved oxygen.