Nutrient removal process selection for planning and design of large wastewater treatment plant upgrade needs

A protocol to select nutrient removal technologies that can achieve low nutrient effluents (total nitrogen (TN) < 5 mg/L and total phosphorus (TP) < 0.5 mg/L) was developed for different wastewater treatment plant (WWTP) sizes based on the research conducted during a Water Environment Research Foundation funded project. The adaptable protocol includes technology and cost assessment of feasible (pre-screened) nutrient removal technologies that are being successfully implemented at full scale. The information collected from the full scale nutrient removal plants to develop this protocol includes design, operational, performance, and cost data through a direct survey of plants, and published data. The protocol includes a “technology threshold” approach consisting of Tier I (TN < 5.0 mg/L; TP < 0.5 mg/L) and Tier II (TN < 3.0 mg/L; TP < 0.1 mg/L) effluent nutrient levels for different plant sizes. A very large WWTP (1,250,000 m³/day flow) in Chicago, Illinois, USA adapted this protocol for master planning and design of future nutrient removal facilities based on plant and site specific criteria.