Collaborative wastewater project points the way to improved phosphorus removal

The removal of phosphorus and other nutrients from wastewater is critical to preventing harmful algal blooms in coastal waters. Enhanced biological phosphorus removal (EBPR) — which relies on microbial communities that consume phosphate, reducing its concentration in the wastewater — has been used for decades, but the microbial ecology and optimal design of the systems are not fully understood.

Now, a large collaborative research project led by Black & Veatch and funded in part by the Water Research Foundation is developing guidelines for municipal wastewater treatment plants for using side-stream EBPR, a set of configurations for biological phosphorus removal that aims to increase the stability of the treatment system against variations in the influent water, as well as to lower costs.

“In side-stream EBPR, a portion of the wastewater biomass enters a side fermentation tank where bacterial communities are selected for the fermentative conditions that are best for phosphate removal,” said Leon Downing, Black & Veatch engineer and principal investigator of the research project. And those microbe communities are introduced back into the treatment system to lower the phosphorus concentration.

“By looking at different arrangements of wastewater treatment assets, and different fermentation conditions, we are making progress in understanding how to optimize the EBPR process and make it easier for municipalities to implement the technology to improve the stability of phosphorus removal and lower costs,” Downing added.

The two-and-a-half-year project involves five consulting firms, five universities and 19 water utility partners in the U.S. and Canada.