TY - JOUR
T1 - Reduction of Chromate via Biotic and Abiotic Pathways in the Presence of Three Co-contaminating Electron Acceptors
AU - Long, Min
AU - Zhou, Chen
AU - Zheng, Xiong
AU - Rittmann, Bruce E.
N1 - Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/12/19
Y1 - 2023/12/19
N2 - Bioreduction of Cr(VI) to Cr(III) is a promising technology for removing Cr(VI), but Cr(VI) reduction alone cannot support microbial growth. This study investigated the reduction of Cr(VI) in the presence of three electron acceptors that typically coexist with Cr(VI): NO3-, SO42-, and Fe(III). All three systems could reduce Cr(VI) to Cr(III), but the fate of Cr, its impacts on reduction of the other acceptors, and its impact on the microbial community differed. Although Cr(VI) was continuously removed in the NO3--reduction systems, batch tests showed that denitrification was inhibited primarily through impeding nitrite reduction. The SO42- and Fe(III) reduction systems reduced Cr(VI) using a combination of biotic and abiotic processes. Across all three systems, the abundance of genera capable of reducing Cr(VI) increased following the introduction of Cr(VI). Conversely, the abundance of genera that cannot reduce or resist Cr(VI) decreased, leading to restructuring of the microbial community. Furthermore, the abundance of sulfide oxidizers and Fe(II) oxidizers substantially increased after the introduction of chromate. This study provides fundamental knowledge about how Cr(VI) bioreduction interacts with bioreductions of three other co-contaminating electron acceptors.
AB - Bioreduction of Cr(VI) to Cr(III) is a promising technology for removing Cr(VI), but Cr(VI) reduction alone cannot support microbial growth. This study investigated the reduction of Cr(VI) in the presence of three electron acceptors that typically coexist with Cr(VI): NO3-, SO42-, and Fe(III). All three systems could reduce Cr(VI) to Cr(III), but the fate of Cr, its impacts on reduction of the other acceptors, and its impact on the microbial community differed. Although Cr(VI) was continuously removed in the NO3--reduction systems, batch tests showed that denitrification was inhibited primarily through impeding nitrite reduction. The SO42- and Fe(III) reduction systems reduced Cr(VI) using a combination of biotic and abiotic processes. Across all three systems, the abundance of genera capable of reducing Cr(VI) increased following the introduction of Cr(VI). Conversely, the abundance of genera that cannot reduce or resist Cr(VI) decreased, leading to restructuring of the microbial community. Furthermore, the abundance of sulfide oxidizers and Fe(II) oxidizers substantially increased after the introduction of chromate. This study provides fundamental knowledge about how Cr(VI) bioreduction interacts with bioreductions of three other co-contaminating electron acceptors.
KW - Fe(III) reduction
KW - chromate reduction
KW - denitrification
KW - microbial community structure and function
KW - sulfate reduction
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U2 - 10.1021/acs.est.3c04812
DO - 10.1021/acs.est.3c04812
M3 - Article
C2 - 38051765
AN - SCOPUS:85180105307
SN - 0013-936X
VL - 57
SP - 21190
EP - 21199
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 50
ER -