Effect of phosphorus load on nutrients removal and N2O emission during low-oxygen simultaneous nitrification and denitrification process

► TP and TN removal was enhanced simultaneously with the increase of phosphorus load. ► Simultaneous N and P removal was due to denitrification of PAOs under high P load. ► N2O emission was reduced with the increase of P load during low-oxygen SND process. ► N2O yield by heterotrophic denitrification was reduced under high P load. ► The enrichment of PAOs instead of GAOs led to low N2O yield under high P load.