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Adapting a denitrifying biocathode for perchlorate reduction

TitleAdapting a denitrifying biocathode for perchlorate reduction
Publication TypeJournal Article
Year of Publication2008
AuthorsShea C, Clauwaert P, Verstraete W, Nerenberg R
JournalWater, Science and Technology
Volume58
Issue10
Start Page1941
Pagination1941-1946
Date Published11/2008
Keywordsbiocathode, Microbial fuel cells, perchlorate
Abstract

Perchlorate is widely used as a propellant in the aerospace and defense industries, and is of environmental concern due to its high mobility and inhibiting effect on thyroid function. An ideal treatment approach is bioreduction to chloride via dissimilatory perchlorate-reducing bacteria (PCRB). PCRB are ubiquitous in the environment, and are mainly facultative anaerobes and denitrifiers. Previous research suggests that PCRB may grow using a cathode as an electron donor, although this research was performed in a half cell with exogenous electron shuttles. We investigated a functioning MFC with a denitrifying biocathode for perchlorate reduction, as a means to confirm the existence of biocathode-utilizing PCRB and the possibility of perchlorate remediation without added shuttles. The biocathode was initially run with 20 mgN/L nitrate. The perchlorate concentration was increased stepwise from 0.1 mg/L to 20 mg/L, while the nitrate concentration was decreased from 20 mgN/L to 5 mgN/L. The maximum perchlorate removal was 12 mg/L-d, contributing 64% to the 0.28 mA produced by the cell. Given the lack of soluble electron donor in the medium, the extent of perchlorate reduction, and the improvement of perchlorate reduction over time, these tests strongly suggest PCRB are utilizing the cathode as an electron donor without exogenous electron shuttles.

DOI10.2166/wst.2008.551