Comparison of performance, microorganism populations, and bio-physiochemical properties of granular and flocculent sludge from denitrifying phosphorus removal reactors

- Denitrifying P removal and nitrite tolerance was compared between flocs and granules.
- Granules had higher resistance to nitrite/FNA due to the mass transfer resistance.
- Granular sludge had a higher PAOs content than flocs sludge.
- PAOII dominated in both systems and performed anoxic P removal cooperated with DGAOs.
- PAOs and GAOs existed in different depths in granules.