The Theoretical Benefits of Mainstream Shortcut Nitrogen Removal Revisited and Validated by Full-scale Implementation of Partial Denitrification-Anammox

This study revisits the theoretical background of shortcut nitrogen removal to include PdNA and resolve existing discrepancies and gaps in the literature, and demonstrates the application of full-scale mainstream shortcut nitrogen removal at the Hampton Roads Sanitation District (HRSD) York River (YR) Treatment Plant. The efficiency of the conventional nitrification/denitrification was compared to shortcut nitrogen removal in the context of real process configurations with respect to aeration, supplemental carbon, alkalinity, minimum influent C/N ratio required, and aerobic SRT (capacity) requirements. Stoichiometric tables were developed from the existing literature in a manner compatible with ASM1 matrices. To compare processes in different contexts, mass balances were developed for each nitrogen removal process that included the fraction of oxidized nitrogen reduced via influent COD. The results from YRTP support this theoretical framework and demonstrate that shortcut nitrogen removal is possible in full scale mainstream processes without NOB out-selection.