A Novel Application of Acid-phase Digestion for Concurrent Filament Destruction and Soluble COD Recovery from Froth

New York City Department of Environmental Protection (NYCDEP) in conjunction with Metcalf and Eddy has been involved in a comprehensive effort to optimize Step Feed Biological Nitrogen Removal under the purview of the PO-55A Applied Research Program. To this end, extensive pilot-scale studies have been conducted at the 26th Ward Water Pollution Control Plant (WPCP), focusing on process optimization issues such as reactor configuration and supplemental carbon demands as well as process implementation issues such as froth control, treatment and disposal. In this study we focus on the application of acid-phase digestion of froth for concurrent filament destruction and soluble COD generation.Given the biological nature of froth, it is postulated that soluble carbon resulting from acid-phase froth digestion may be used to promote denitrification in carbon limited wastewater streams, potentially offering significant savings compared to utilization of commercially available supplemental carbon sources such as methanol. Further, acid-phase digestion of froth could be an effective strategy for filament destruction therein.The applicability of acid-phase digestion as a strategy for filament destruction and sCOD production from froth has been demonstrated in bench-scale and full-scale experiments. Ongoing work is aimed at determining the feasibility of applying the sCOD derived from thermophilic acid-phase digestion to improve denitrification performance in BNR pilot reactors.