Abstract:The performance of enhanced biological phosphorus removal (EBPR) and the activity of functional microorganisms community in ten municipal wastewater treatment plants in north region of Zhejiang Province were investigated. The rates of average P release and uptake were found about 2.4mg/(g·h), and 2.2mg/(g·h), respectively. Denitrifying polyphosphate accumulating organisms (DNPAOs) were estimated to be 0.0%-80.1% of the polyphosphate accumulating organisms (PAOs). And the fractions of Accumulibacter as the family of PAOs, and Competibacter as potential glycogen accumulating organisms (GAOs) were quantified using fluorescence in situ hybridization (FISH). The proportions of PAOs and GAOs were varied from 2.0% to 8.7%, and 1.3% to 22.4%, respectively. So it’s a great challenge for these wastewater treatment plants to meet the higher requirements for discharge. It should be better to reduce the industrial wastewater proportions and set a separate pre-denitrifying tank to favor EBPR system.