Biological Nitrate Removal From Drinking Water

The City of Taylorville, IL, needed to diversify their drinking water sources by bringing unused groundwater wells online to supplement their surface water supply. Unfortunately, their groundwater contained nitrate levels that exceeded regulatory limits and would require treatment.

The City’s consulting engineer, Benton & Associates, weighed various treatment options to bring the groundwater’s nitrate into compliance. The major treatment contenders being considered were ion exchange and biological treatment. Since ion exchange produces a high-strength brine waste containing concentrated levels of nitrate, concerns were raised over how this waste stream would affect the wastewater treatment plant and the environmental impacts of releasing the concentrated nitrate back into nature.

Due to these concerns, biological treatment — more specifically, AdEdge’s biottta® process — was selected to treat the City’s drinking water without producing a high-strength brine waste. biottta is a fixed-bed biological denitrification process that destroys nitrate instead of concentrating it into a waste stream that ultimately ends up being released back into the environment. The process harnesses the natural bacteria that exist in groundwater to produce clean, safe drinking water with less than 0.1 mg/L nitrate nitrogen (NO3-N), and only requires periodic backwashing instead of regeneration.

AdEdge worked closely with the City and engineer to conduct an onsite pilot in 2016. The successful results were presented to the Illinois EPA, and the City was permitted to move on to full-scale implementation of the 3-MGD biottta process, which is the first drinking water biological denitrification system in the state of Illinois. The full-scale system was started up in June 2019, and this presentation will discuss system performance, optimization, biological acclimation, and lessons learned from the pilot and full-scale treatment processes. The presentation is ideally suited for engineers, end users, and operators seeking assistance in making sound decisions for innovative treatment of nitrate and other contaminants.