DOI: 10.1016/j.watres.2018.09.034
Scopus记录号: 2-s2.0-85055019374
论文题名: Two-stage chromium isotope fractionation during microbial Cr(VI) reduction
作者: Chen G. ; Han J. ; Mu Y. ; Yu H. ; Qin L.
刊名: Water Research
ISSN: 431354
出版年: 2019
卷: 148 起始页码: 10
结束页码: 18
语种: 英语
英文关键词: Bioavailability
; Chromium isotope fractionation
; Mass-transfer limitations
; Microbial Cr(VI) reduction
; The values of ε
Scopus关键词: Bacteria
; Biochemistry
; Groundwater
; Isotopes
; Mass transfer
; Radioactive tracers
; Bioavailability
; Biogeochemical cycling
; Controlled experiment
; Cr reductions
; Environmental conditions
; Isotope fractionation
; Mass transfer limitation
; Shewanella oneidensis MR-1
; Chromium compounds
; chromium
; ground water
; nitrate
; sulfur
; assessment method
; bacterium
; bioavailability
; chromium
; concentration (composition)
; experimental study
; isotopic fractionation
; isotopic ratio
; mass transfer
; microbial activity
; reduction
; Alternaria alternata
; Article
; bacterial growth
; bioavailability
; biogeochemical cycling
; fractionation
; nonhuman
; pH
; Shewanella oneidensis
; substrate concentration
; temperature
; Shewanella oneidensis MR-1
英文摘要: Chromium isotope fractionation analysis is a promising approach for the assessment of microbial Cr(VI) reduction in groundwater. Understanding the mechanisms and other parameters that control Cr isotope fractionation factors (between the product Cr(III) and reactant Cr (VI)) in microbial Cr(VI) reduction is critical to this application. To date, such studies are very limited. Here, the influence of critical factors on observed Cr isotope fractionation during Cr(VI) reduction by Shewanella oneidensis MR-1 under various conditions was investigated. The Cr(VI) concentration and Cr isotope ratio measurements were conducted on unreacted Cr(VI) remaining in solution to determine Cr isotope fractionation factors. The changes in ambient environmental conditions (e.g., pH, temperature) have limited influence on Cr isotope fractionation factors. However, as a result of Cr(VI) consumption as the experiments proceed, the change in bioavailability of Cr(VI) has a significant impact on Cr isotope fractionation factors. For example, in temperature-controlled experiments, Cr isotope fractionation showed two-stage behavior: during Stage I, the values of ε were −2.81 ± 0.19‰ and −2.60 ± 0.14‰ at 18 °C and 34 °C, respectively; during Stage II, as Cr(VI) reduction progressed, Cr isotope fractionation was significantly masked, and the ε values decreased to −0.98 ± 0.49‰ and −1.01 ± 0.11‰ at 18 °C and 34 °C, respectively. Similar two-stage isotope fractionation behaviors were observed in pH-controlled experiments (pH = 6.0 and 7.2) and in experiments with and without the addition of a competing electron acceptor (nitrate). Masking of isotope fractionation in Stage II indicated restrictions on the bioavailability of Cr(VI) and mass-transfer limitations. This study provides an explanation for the variation in Cr isotope fractionation factors during microbial Cr(VI) reduction in the environment, furthering the viability of Cr isotope ratio analysis as an approach in understanding Cr biogeochemical cycling. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/122230
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: CAS Key Laboratory of Crust–Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China; CAS Key Laboratory for Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China; State Key Laboratory of Geological Processes and Mineral Resources, University of Geosciences, Beijing, China
Recommended Citation:
Chen G.,Han J.,Mu Y.,et al. Two-stage chromium isotope fractionation during microbial Cr(VI) reduction[J]. Water Research,2019-01-01,148