Testing the Limits of EBPR for Stable Operation

Achieving low effluent phosphorus limits (<0.1 mg/L) using enhanced biological phosphorus removal (EPBR) requires stability of the biological process. Additional chemical phosphorus removal (CPR) to supplement EBPR is need to polish any remaining ortho-phosphorus. Instability in the EBPR process will cause chemical use to increase. The chemical addition can lead to increasing reliance on CPR over EBPR. The Rock Creek Advanced Wastewater Treatment Facility (AWWTF) is conducting testing to improve EBPR through modifications to allow more flexibility in process flow configurations.Working with the team of the WERF Project on SSEBPR, testing has been conducted since 2016 to better understand process configurations that can improve EBPR stability. The process configurations that were tested were conventional three-stage, modified Westbank, and Side-Stream Enhanced Biological Phosphorus Removal (SSEBPR). The objective of the ongoing operational research is to evaluate and compare the performance among different EBPR configurations and reveal the underlying mechanisms via microbial population analysis, with the aim to learn which configurations and associated microbial community structure and phenotypes are most successful, and the principal factors that influence their success and failure.