Nitrogen and phosphorus are two major pollutants that lead to eutrophication, adversely impact ecosystems, and lead to degradation of water quality, which impacts human health and sustainability. Pollution from point sources like wastewater and industry discharge is easier to control than non-point source pollution due to agricultural runoff and related activities. The USEPA is considering more strict standards for nitrogen and phosphorus discharge from point sources. The objective of this study was to use an appropriate low-cost wastewater technology to demonstrate removal of nitrogen from wastewater discharge using rotating biological contactors (RBCs) using different C:N ratios. The first-order nitrogen removal rate constant was found to be about 3.88 day-1 in experimental reactor systems, using RBC media from a local wastewater treatment plant (Greater Peoria Sanitary District). Phase I experiments, at C:N ratio of 2:1, with nitrogen removal rates of 60% in a single flow- through system. Phase II experiments for the limited carbon availability condition showed that the removal rate constant reduced by 30% and N-removal efficiency dropped to around 48%. Modeling showed that even under these conditions, multiple bioreactors operated in series could help achieve design treatment goals. The system achieved stability within a week of operation. Economics and sustainability issues are analyzed to determine if the process developed in this research is scalable to pilot- and full-scale conditions.
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