Rare earth element impacts on microbial nitrogen cycling

image with text biological treatment of REE impacted wastewater

CMI researchers at Idaho National Laboratory and Colorado School of Mines conducted the research for this highlight

Innovation 
Observed that high (≥1 µM) soluble concentrations of yttrium or gadolinium caused transient inhibition of microbial ammonia removal, and changes in abundance of specific microbial populations.

Achievement
In bioreactors simulating aerobic wastewater treatment, 50 ppm Y or Gd additions impaired ammonia oxidation, but after cessation of REE treatment, microbial communities recovered. 

Significance and Impact
For REE-laden industrial or mining waters that could reach the environment, site-specific studies of  ecological impacts may be warranted.

Hub Target Addressed 
Supporting environmentally sustainable technologies for critical material processing.

Ammonia nitrogen breakthrough indicative of nitrification impairment was observed after Y amendments reached ≥25 ppm Y or Gd amendments reached ≥ 50 ppm Gd, but ammonia removal resumed after REE addition stopped.
Ammonia nitrogen breakthrough indicative of nitrification impairment was observed after Y amendments reached ≥25 ppm Y or Gd amendments reached ≥ 50 ppm Gd, but ammonia removal resumed after REE addition stopped.

Salmon, O.;  Rasmussen, K.;  Aurelius, S.;  Vanzin, G.;  Munakata-Marr, J.; Fujita, Y., 2022. ACS ES&T Water 2022. https://doi.org/10.1021/acsestwater.2c00098