کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6366141 | 1623092 | 2015 | 10 صفحه PDF | دانلود رایگان |
- Nearly complete nitrate removal by anaerobic bioreactors with influent Cr(VI) at 120Â mg/L.
- Application of high-throughput sequencing technologies to characterize microbial community structure and function.
- Predominance of Thauera and Halomonas in the bioreactor fed with Cr(VI).
- Different responses of Thauera and Halomonas to Cr(VI) stress.
In this study, a lab-scale expanded granular sludge bed reactor was continuously operated to treat high-nitrate wastewater containing different concentrations of hexavalent chromium (Cr(VI)). Nearly complete nitrate removal was achieved even at 120Â mg/L influent Cr(VI). Pyrosequencing of 16S rRNA gene showed that Cr(VI) decreased the biodiversity of the bacterial community and potential denitrifiers. Proteobacteria dominated in the bioreactor, and Betaproteobacteria had increased abundance after Cr(VI) feeding. Thauera and Halomonas were the two predominant genera in the bioreactor fed with Cr(VI), demonstrating opposite responses to the Cr(VI) stress. Metagenomic analysis indicated that Cr(VI) feeding posed no obvious effect on the overall function of the bacterial community, but altered the abundance of specific denitrifying genes, which was evidenced by quantitative real time PCR. This study revealed that Halomonas mainly contributed to the denitrification under no or low Cr(VI) stress, while Thauera played a more important role under high Cr(VI) stress.
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Journal: Water Research - Volume 76, 1 June 2015, Pages 43-52