Details
| Original language | English |
|---|---|
| Pages (from-to) | 10553-10561 |
| Number of pages | 9 |
| Journal | Environmental Science and Technology |
| Volume | 49 |
| Issue number | 17 |
| Publication status | Published - 1 Sept 2015 |
Abstract
The prevalent formation of noncrystalline U(IV) species in the subsurface and their enhanced susceptibility to reoxidation and remobilization, as compared to crystalline uraninite, raise concerns about the long-term sustainability of the bioremediation of U-contaminated sites. The main goal of this study was to resolve the remaining uncertainty concerning the formation mechanism of noncrystalline U(IV) in the environment. Controlled laboratory biofilm systems (biotic, abiotic, and mixed biotic-abiotic) were probed using a combination of U isotope fractionation and X-ray absorption spectroscopy (XAS). Regardless of the mechanism of U reduction, the presence of a biofilm resulted in the formation of noncrystalline U(IV). Our results also show that biotic U reduction is the most effective way to immobilize and reduce U. However, the mixed biotic-abiotic system resembled more closely an abiotic system: (i) the U(IV) solid phase lacked a typically biotic isotope signature and (ii) elemental sulfur was detected, which indicates the oxidation of sulfide coupled to U(VI) reduction. The predominance of abiotic U reduction in our systems is due to the lack of available aqueous U(VI) species for direct enzymatic reduction. In contrast, in cases where bicarbonate is present at a higher concentration, aqueous U(VI) species dominate, allowing biotic U reduction to outcompete the abiotic processes. (Figure Presented).
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Environmental Science(all)
- Environmental Chemistry
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In: Environmental Science and Technology, Vol. 49, No. 17, 01.09.2015, p. 10553-10561.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Mechanism of Uranium Reduction and Immobilization in Desulfovibrio vulgaris Biofilms
AU - Stylo, Malgorzata
AU - Neubert, Nadja
AU - Roebbert, Yvonne
AU - Weyer, Stefan
AU - Bernier-Latmani, Rizlan
PY - 2015/9/1
Y1 - 2015/9/1
N2 - The prevalent formation of noncrystalline U(IV) species in the subsurface and their enhanced susceptibility to reoxidation and remobilization, as compared to crystalline uraninite, raise concerns about the long-term sustainability of the bioremediation of U-contaminated sites. The main goal of this study was to resolve the remaining uncertainty concerning the formation mechanism of noncrystalline U(IV) in the environment. Controlled laboratory biofilm systems (biotic, abiotic, and mixed biotic-abiotic) were probed using a combination of U isotope fractionation and X-ray absorption spectroscopy (XAS). Regardless of the mechanism of U reduction, the presence of a biofilm resulted in the formation of noncrystalline U(IV). Our results also show that biotic U reduction is the most effective way to immobilize and reduce U. However, the mixed biotic-abiotic system resembled more closely an abiotic system: (i) the U(IV) solid phase lacked a typically biotic isotope signature and (ii) elemental sulfur was detected, which indicates the oxidation of sulfide coupled to U(VI) reduction. The predominance of abiotic U reduction in our systems is due to the lack of available aqueous U(VI) species for direct enzymatic reduction. In contrast, in cases where bicarbonate is present at a higher concentration, aqueous U(VI) species dominate, allowing biotic U reduction to outcompete the abiotic processes. (Figure Presented).
AB - The prevalent formation of noncrystalline U(IV) species in the subsurface and their enhanced susceptibility to reoxidation and remobilization, as compared to crystalline uraninite, raise concerns about the long-term sustainability of the bioremediation of U-contaminated sites. The main goal of this study was to resolve the remaining uncertainty concerning the formation mechanism of noncrystalline U(IV) in the environment. Controlled laboratory biofilm systems (biotic, abiotic, and mixed biotic-abiotic) were probed using a combination of U isotope fractionation and X-ray absorption spectroscopy (XAS). Regardless of the mechanism of U reduction, the presence of a biofilm resulted in the formation of noncrystalline U(IV). Our results also show that biotic U reduction is the most effective way to immobilize and reduce U. However, the mixed biotic-abiotic system resembled more closely an abiotic system: (i) the U(IV) solid phase lacked a typically biotic isotope signature and (ii) elemental sulfur was detected, which indicates the oxidation of sulfide coupled to U(VI) reduction. The predominance of abiotic U reduction in our systems is due to the lack of available aqueous U(VI) species for direct enzymatic reduction. In contrast, in cases where bicarbonate is present at a higher concentration, aqueous U(VI) species dominate, allowing biotic U reduction to outcompete the abiotic processes. (Figure Presented).
UR - http://www.scopus.com/inward/record.url?scp=84940853021&partnerID=8YFLogxK
U2 - 10.1021/acs.est.5b01769
DO - 10.1021/acs.est.5b01769
M3 - Article
C2 - 26251962
AN - SCOPUS:84940853021
VL - 49
SP - 10553
EP - 10561
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 0013-936X
IS - 17
ER -