The Water Environment Research Federation (WERF) recently published results of a study completed by HDR examining the reliability of enhanced biological phosphorus removal (EBPR) in removing phosphorus to low levels in wastewater effluent. The goal of the research project was to develop information that can be used to help municipal wastewater treatment plants more efficiently and cost-effectively remove phosphorus through EBPR processes.
The project included detailed analyses of routine water quality and operating data, field testing observations, and special studies conducted over the course of the project to evaluate the variability of EBPR, factors influencing EBPR performance and the relationship between EBPR and the presence of glycogen accumulating organisms (GAOs).
The study showed that EBPR is capable of achieving very low effluent phosphate concentrations. When operating well, it is possible to achieve soluble phosphate concentrations under 0.1 mg/L. However, many facilities struggle to routinely achieve soluble phosphate concentrations under 1.0 mg/L. For this reason, most facilities experience significant variability in EBPR performance, requiring augmentation of EBPR through the use of substrate addition or polishing with iron- or aluminum-containing chemicals.
Contributing HDR authors are JB Neethling, Ph.D., P.E., DEE; Brian Bakke, P.E.; Mario Benisch; April Gu, Ph.D; and Heather Stephens, P.E.