2020 Virtual undergraduate Research symposium

The Recovery of Nitrification Activity in Aerobic Bioreactors after Stopping Rare Earth Element Addition


PROJECT NUMBER: 38

AUTHOR: Diana Teran, Civil and Environmental Engineering | AUTHOR: Leonard Igberaese, Mechanical Engineering

MENTOR: Junko Munakta-Marr, Civil and Environmental Engineering | MENTOR: Gary Vanzin, Civil and Environmental Engineering

MENTOR: Yoshiko Fujita

 

ABSTRACT

Rare earth elements (REEs) are increasingly used in modern industries. This growing use of REEs increases the likelihood of REEs reaching municipal wastewater treatment facilities, which rely heavily on microorganisms for containment removal. However, the impacts of REEs on the wastewater treatment microbial communities, and whether those communities can recover from exposure to REEs, is unclear.

To understand the effects of REEs on wastewater treatment microbial communities, a bench-scale aerobic bioreactor system was developed. Test reactors were treated with yttrium (Y) or gadolinium (Gd) while the control reactor received no REEs. All three reactors were seeded with activated sludge from a full-scale wastewater treatment facility and wastewater quality parameters were tracked. These studies demonstrate inhibition of nitrification, key to wastewater nitrogen removal, at 25 ppm Y and 50 ppm Gd. Reactors were subsequently fed with REE-free synthetic wastewater to determine whether the recovery of the reactor performance was possible.

Results show full recovery of nitrification in both Gd- and Y- treated reactors. While both test reactors successfully recovered, the Y-treated reactor recovered more slowly. The recovery of nitrite-oxidizing bacteria appeared to be slower than that of ammonium-oxidizing bacteria in the Y-treated reactor.

 

 

VISUAL PRESENTATION

 

AUTHOR BIOGRAPHIES

Diana is a Junior in the Civil and Environmental Engineering Department majoring in Environmental Engineering. This research project was conducted in partnership with the Idaho National Laboratory as a part of the Critical Materials Institute’s efforts to eliminate and reduce reliance on rare earth elements critical to the success of clean energy technologies. Previous to this project, Diana participated in a PIRE program aimed to make artisinal and small scale gold mining more sustainable. Future research aspirations of Diana include ones that combine technical and humanitarian aspects or focus on water quality issues.

Leonard Igberaese is a junior majoring in Mechanical Engineering and minoring in Biochemical engineering. This research project, in partnership with the Idaho National Laboratory as a part of the Critical Materials Institute’s initiative to investigate the impacts of rare earth elements on microbial communities, it is in the Civil and Environmental Engineering department . His role for this project was to collect and analyze samples from aerobic reactors while also making sure the reactors were sustained. He would like to be a part of research that deals with medical devices.

 


2 Comments

  1. Good work!

  2. Hello Diana and Leonard, great work here!

    The poster, while it has lots of good information here is very wordy, Which is great for digital presentations, but some of the blocks of texts could be simplified with a simple schematic or such to delivery information more quickly to the audience.

    Also, while the methods of your experiment are important, what seemed more interesting for a broader and scientific audience is spending more attention on your findings. How you reached your conclusions, what it means, and the impact it will have to society and the scientific community.

    Well done!

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