Evaluation of the Performance of a Revolving Algae Biofilm System for Recovering Nitrogen and Phosphorus from Municipal Wastewater Thomas E. Kunetz* 1 , Kuldip Kumar 1 , Martin A. Gross 2 , and Zhiyou Wen 2 1 Metropolitan Water Reclamation District of Greater Chicago, 100 East Erie Street Chicago, IL 60611, USA 2 Agricultural and Biological Systems Engineering, Iowa State University, Ames, IA 50011, USA *Corresponding author: kunetzt@mwrd.org ABSTRACT An innovative algal biofilm technology is being pilot tested for potential application as a sustainable means for nitrogen (N) and phosphorus (P) recovery at Wastewater Resource Recovery Facilities (WRRFs). The technology uses revolving belts that extend vertically up from the wastewater to provide sunlight for microalgae growth. This Revolving Algae Biofilm (RAB) reactor has demonstrated the ability to recover nutrients in a smaller footprint than traditional raceway ponds. The resultant biomass is easily harvested from the biofilm with a scraping mechanism, providing an algae product that is ready to be processed for use as a biomass feedstock for bioplastics, fertilizers, biofuels, aquaculture feed, and other sustainable products. A pilot plant is in place at a major WRRF to test the performance of the RAB on a variety of wastewater streams. The results of a half year operation plus operating experiences are presented. Keywords: Algae, Nutrient removal, Algae biomass, Phosphorus removal; Revolving algae biofilm reactor. INTRODUCTION In anticipation of future phosphorus (P) effluent discharge limits, the Metropolitan Water Reclamation District of Greater Chicago (MWRD) is evaluating options for implementation of P recovery at the Terrence J. O’Brien Wastewater Resource Recovery Facility (O’Brien WRRF). The O’Brien WRRF employs primary clarification and conventional activated sludge for the removal of TSS, BOD and ammonia. Primary and waste activated sludge are combined in gravity concentration tanks for thickening, for transportation to another water reclamation plant for treatment. Supernatant from the gravity concentration tanks is recycled to the headworks. The plant treats typical dilute municipal sewage with some industrial contribution at an average daily flow rate of 870 MLD (230 MGD). Peak flows occur during heavy wet weather events due to the combined sewer system tributary to the plant and can reach 1,900 MLD (500 MGD). The key primary wastewater influent and plant effluent characteristics after secondary treatment WEFTEC 2016 Copyright ©2016 Water Environment Federation 2988