Chlorate addition enhances perchlorate reduction in denitrifying membrane-biofilm reactors

Title

Chlorate addition enhances perchlorate reduction in denitrifying membrane-biofilm reactors

AuthorMarcela Vega, Aura Ontiveros-Valencia, Ignacio T. Vargas & Robert Nerenberg
Line(s)Recursos Críticos
Year of Publication2022
Journal TitleApplied Microbiology and Biotechnology
KeywordsChlorate, Perchlorate-reducing bacteria, Sulfate-reducing bacteria, MBfR
AbstractPerchlorate is a widespread drinking water contaminant with regulatory standards ranging from 2 to 18 μg/L. The hydrogen-based membrane-biofilm reactor (MBfR) can effectively reduce perchlorate, but it is challenging to achieve low-µg/L levels. We explored chlorate addition to increase the abundance of perchlorate-reducing bacteria (PRB) and improve removals. MBfR reactors were operated with and without chlorate addition. Results show that chlorate doubled the abundance of putative PRB (e.g., Rhodocyclales) and improved perchlorate reduction to 23 ± 17 µg/L, compared to 53 ± 37 µg/L in the control. Sulfate reduction was substantially inhibited during chlorate addition, but quickly recovered once suspended. Our results suggest that chlorate addition can enhance perchlorate reduction by providing a selective pressure for PRB. It also decreases net sulfate reduction.enrichment techniques are included.
Doihttps://doi.org/10.1007/s00253-022-11976-1
Corresponding AuthorIgnacio Vargas itvargas@ing.puc.cl