With Wessex Water they identified a combined municipal and industrial wastewater stream was resulting in significant variations in organic load arriving to the WWTP.
The challenge in aeration optimization is the requirement for a reliable, low-maintenance water quality monitor that could accurately profile the biological demand of the in-coming wastewater.
Wessex chose to work with SENTRY as a tool to provide early warning on wastewater conditions. The key questions they asked:
Could a bio-electrode sensor provide an in-situ reading prior to the aeration basins to:
1.Predict (feed-forward) the biological demand of the wastewater stream?
2.Profile the weekly loading patterns and identify key imbalance triggers?
The installation provided key insights to operators on the impact of industrial discharge and the role inflow and infiltration has in impacting biological activity. Some key insights included:
●Weekly trends demonstrated average lowest loadings around 12-3pm.
●Seasonal effect of loading seen with Aug and Sept on average >50% sensor activity than Oct and Nov.
●Correlations observed with manual BOD-5 and inline COD readings
Annual energy use on site is in the region of £500,000. These costs are primarily comprised of aeration energy required for the three treatment streams and UV disinfection.
In leveraging the SENTRY data is is estimated a target of a 10 - 20% energy savings provides a potential for savings in the region of £50,000 - £100,000 per annum with improved aeration efficiency.