ENHANCED METALS REMOVAL USING AN MBR – MODELING AND BENCH-SCALE TESTING

In the development of a new treatment facility for a community in northwestern Indiana, very stringent ammonia-N and metals effluent discharge limits (specifically, 0.2 mg/L for ammonia-N, 2.5 μg/L for copper and 1.3 ng/L for mercury) have been issued to address Great Lakes Initiative discharge standards. The Membrane Bioreactor (MBR) was identified as a process that has the potential to achieve those limits at a reasonable cost, however, it was not possible to evaluate the metals removal efficiency of the MBR technology based on published literature. A modeling and piloting study was undertaken to evaluate the process performance and design criteria for a full-scale facility. The modeling effort suggested and the bench-scale piloting demonstrated, the 0.2 mg/L ammonia-N limit could be consistently achieved. Results demonstrated that the MBR technology applied in the bench-scale piloting had superior metals removal ability over conventional treatment.