Westside Process Replaces TF/AS at Central Valley WRF to Meet New Utah State Phosphorus Regulation

摘要

To comply with the State of Utah's promulgated effluent TP limit of 1 mg/L, the Central Valley Water Reclamation Facility (CVWRF) will replace its existing Trickling Filter Activated Sludge (TF/AS) process with a modified Westside activated sludge process. The primary effluent was found to be deficient in readily degradable carbon required for the process to meet the new limits under future design loads. It was estimated that the carbon shortfall could be made up through fermentation of primary and secondary (RAS) sludges. Given the limited application of the modified Westside technology and the general lack of understanding of RAS fermentation mechanisms, a 38 L/min (10 gpm) pilot demonstration was undertaken over 5 months to inform the process design of the plant upgrade. The results showed the ability of the process to meet all projected regulations without the need for an external carbon supplement using RAS fermentation with primary sludge fermentate added as a carbon supplement. Modeling of the results provided evidence of RAS fermentation, when operating in the Westside configuration.