Performance Evaluation of Nutrient Removal from Stormwater Runoff by Grey and Green Infrastructure

The prompt growth in impermeable surfaces in urban areas did not only cause the increased flood volumes and stormwater peak flow, but also exacerbated the wash-off of pollutants, which could seriously deteriorate the runoff water quality. Stormwater runoff could contain various nutrient contaminants such as organic matter, phosphorus and nitrogen. In this study, the p erformance of nutrient removal from stormwater runoff by grey and green infrastructure was evaluated from the engineering, environmental and economic aspects. Different types of grey infrastructures such as anaerobic-anoxic-oxic, oxidation ditches, and membrane bioreactors were selected, while different green infrastructures such as stabilization ponds, constructed wetlands and bioretention systems were selected. The environmental impacts of grey and green infrastructure were quantified using the life cycle assessment. As a part of this study, the implications and opportunities for deploying grey and green infrastructure for optimizing water-energy nexus and stormwater management were illustrated.