Simultaneous nitrogen removal and phosphorus recovery in granular sludge-based partial denitrification/anammox-hydroxyapatite precipitation (PD/A-HAP) process under low C/N ratio and dissolved oxygen limitation

Lijie Chen, Zhenjun Wu, Jiayu Niu, Yihan Wang, Ming Cai, Jiale Xi, Yi Cui, Lang Cheng, Xinyi Fan