DEMONSTRATION AND FULL SCALE RESULTS OF A PLANT UPGRADE FOR BNR USING INTEGRATED FIXED-FILM ACTIVATED SLUDGE (IFAS) TECHNOLOGY

In September of 2001 the Windsor Locks WPCA near Hartford, CT underwent a facility upgrade from single stage nitrification activated sludge to an MLE process for biological nutrient removal. The upgrade employed the use of a high surface area fixed media to provide additional fixed biomass to the system for complete nitrification. The Integrated Fixed-Film/Activated Sludge (IFAS) process helped the plant compensate for a shorter aerobic retention time after a portion of the existing basin volume was made anoxic. A demonstration test of the IFAS system verses a control train proved that the attached growth biomass contributed towards the removal of ammonia from the wastewater. The full scale IFAS system helped the plant significantly reduce their total nitrogen discharge to the river without building additional aeration basin volume or clarifiers.