Rapid multi-pathway nitrite supply in mainstream anammox via bidirectional hydroxylamine regulation of nitritation/denitritation with substrate positive feedback control

Substrate limitations and microbial competition present significant challenges to the mainstream application of anammox. In this study, advanced nitrogen removal was rapidly achieved by a novel positive feedback regulation strategy based on dual nitrite-induced for the multiple coupling anammox (PNA-(E)PDA) process, when treating real municipal wastewater even at C/N of 2.5.