PNA

As a kind of energy-saving and low-carbon biological nitrogen removal technology, PN/A process has low nitrogen removal rate (NRR) in single-stage system when treating municipal sewage. The root cause is the difference of microbial demand for dissolved oxygen (DO). If different needs can be met at the same time, it has the potential to improve the efficiency of nitrogen removal. Therefore, this study significantly improves nitrogen removal efficiency by separating ammoxidation and anaerobic ammoxidation processes in space.