Format

Send to

Choose Destination
Environ Sci Technol. 2013 Nov 19;47(22):13141-50. doi: 10.1021/es402928b. Epub 2013 Oct 31.

Microbial community changes in hydraulic fracturing fluids and produced water from shale gas extraction.

Author information

1
National Energy Technology Laboratory , Pittsburgh, Pennsylvania 15236, United States.

Abstract

Microbial communities associated with produced water from hydraulic fracturing are not well understood, and their deleterious activity can lead to significant increases in production costs and adverse environmental impacts. In this study, we compared the microbial ecology in prefracturing fluids (fracturing source water and fracturing fluid) and produced water at multiple time points from a natural gas well in southwestern Pennsylvania using 16S rRNA gene-based clone libraries, pyrosequencing, and quantitative PCR. The majority of the bacterial community in prefracturing fluids constituted aerobic species affiliated with the class Alphaproteobacteria. However, their relative abundance decreased in produced water with an increase in halotolerant, anaerobic/facultative anaerobic species affiliated with the classes Clostridia, Bacilli, Gammaproteobacteria, Epsilonproteobacteria, Bacteroidia, and Fusobacteria. Produced water collected at the last time point (day 187) consisted almost entirely of sequences similar to Clostridia and showed a decrease in bacterial abundance by 3 orders of magnitude compared to the prefracturing fluids and produced water samplesfrom earlier time points. Geochemical analysis showed that produced water contained higher concentrations of salts and total radioactivity compared to prefracturing fluids. This study provides evidence of long-term subsurface selection of the microbial community introduced through hydraulic fracturing, which may include significant implications for disinfection as well as reuse of produced water in future fracturing operations.

PMID:
24088205
DOI:
10.1021/es402928b
[Indexed for MEDLINE]

Publication type, MeSH terms, Substances, Secondary source ID

Publication type

MeSH terms

Substances

Secondary source ID

Supplemental Content

Full text links

Icon for American Chemical Society
Loading ...
Support Center