Maximizing Nutrient Removal in an Existing SBR With a Full-Scale BioMag Demonstration

The 1.1-million-gallon-per-day (mgd) city of Taneytown (Maryland) wastewater treatment plant (WWTP) consists of two sequencing batch reactors (SBRs). The city intends to upgrade the existing plant by incorporating BioMag, by Cambridge Water Technology, to provide enhanced nutrient removal (ENR). A full-scale trial of the BioMag system was conducted in 2010, representing its first application to an SBR. BioMag is an enhanced biological wastewater treatment process that uses magnetite, an inert iron ore (Fe3O4), to increase the specific gravity of biological floc, to increase settling rates. This application demonstrated stable, high-level treatment throughout a wide range of influent concentrations. Effluent total nitrogen and total phosphorus concentrations averaged 1.2 milligrams per liter (mg/L) and 0.11 mg/L, respectively. Key components of this application are the ability to increase mixed liquor suspended solids concentrations and appreciably reduce the duration of the settle phase, increasing aerobic and/or anoxic react phase durations.