Wastewater treatment plants are the most basic infrastructures for public health and environmental protection, but they are well known for their intensive energy consumption and large chemical dosing. The development of novel technologies could transform energy and chemical consuming WWTPs into factories for net energy output and resource recovery from wastewater. Currently, with more stringent discharge standard being applied to effluents from WWTPs, especially in nutrient sensitive areas, nitrogen and phosphorus removal technologies have to been adopted to meet the permitted values. Nitrogen is mainly removed by biological methods while phosphorus is primarily precipitated by aluminium or iron salts, leading to chemical requirement, 40% more sludge production and difficulties for P recovery. Given that phosphorus is a non-renewable resource predicted to deplete in the next 50 years and wastewater is a good resource for phosphorus recovery, a new technology will be developed in this project to couple nitrogen removal with phosphorus removal and recovery through a biological approach without chemical dosing. Our preliminary study has shown a correlation between nitrification and phosphorus accumulation in sludge in aerobic condition, which is distinct from traditional enhanced biological phosphorus removal (EBPR) with alternating anaerobic and aerobic conditions. This new phosphorus accumulation method provides a possible way to recover phosphorus without chemical addition or much less chemical addition. This project will thus systematically investigate the environmental factors which affect phosphorus accumulation in sludge and how EBPR could be combined to further enhance phosphorus removal and recovery. A novel process is expected to be developed in a reactor with simple configuration for nutrient removal and phosphorus recovery. In addition, greenhouse gas emission from such process will also be monitored and evaluated.