Acetic Acid to MicroC® 2000: Virginia WWTP Boosts Savings & EBPR Performance

A Virginia municipal 5 MGD wastewater treatment facility discharging to the Potomac River Basin was recently upgraded to achieve enhanced nutrient removal objectives of 4 mg/L of total nitrogen (TN) and 0.3 mg/L of total phosphorus (TP). The major components of the upgrade included two new five-stage biological reactor trains, two new secondary clarifiers, new primary clarifiers, and new tertiary denitrification filters. The upgrade also involved conversion of existing ditches to plug flow reactors, new solids-processing equipment, and adding chemical storage and feed equipment for 20% acetic acid and aluminum sulfate (alum).

The facility was feeding alum to the secondary clarifiers, and optionally feeding alum to the influent of their Parks on Dynasand® continuous-backwash tertiary filters for final trimming of effluent orthophosphate. However, the facility was using VFA (volatile fatty acid) acetic acid as a carbon source for enhanced biological phosphorus removal (EBPR).