SRP493941 PRJNA1084217 Effect of different manganese oxides on biological denitrification and denitrifying phosphorus removal Nutrients including nitrate (NO3--N) and phosphate (P) in aquatic environment have a disturbing effect on eutrophication, which has potential hazards to human health . Denitrification process of NO3--N in wastewater treatment plant is usually restricted due to insufficient organic carbon sources at a low C/N ratio. Compared with physicochemical treatment (e.g., ion exchange, distillation, and electrochemistry), biological denitrification is a safe and effective technology for nutrients removal, its unsatisfactory stability and reaction efficiency limit the application scope of biological denitrification . Biological denitrification has been proven to be crucial for controlling the NO3--N and NO2--N concentrations in ecosystems, which is also a major part of global nitrogen cycle . Therefore, the participation of MnOx and BioMnOx in biological denitrification and denitrifying P removal through Mn redox cycling may be an alternative solution, which can decreased the concentration for organic carbon and O2 in the process.