Biogenic Sulfidation of U(VI) and Ferrihydrite Mediated by Sulfate-Reducing Bacteria at Elevated pH.
Biogenic Sulfidation of U(VI) and Ferrihydrite Mediated by Sulfate-Reducing Bacteria at Elevated pH.
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U（VI）的生物硫化和由硫酸盐还原细菌介导的pH值介导的亚硫酸盐。
DOI：
10.1021/acsearthspacechem.1c00126
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发表时间：
2021-11-18
影响因子：
3.4
通讯作者：
Morris K
中科院分区：
文献类型：
--
作者：
Townsend LT;Kuippers G;Lloyd JR;Natrajan LS;Boothman C;Mosselmans JFW;Shaw S;Morris K
在全球范围内，显然需要进行放射性废物处置和受污染土地管理。在这里，获得一个更好的理解，如铁（III）和硫酸盐还原，生物地球化学过程，可能会控制放射性核素的环境流动性是很重要的。铀（U）是放射性废物和受污染土地中质量最丰富的放射性核素，其环境流动性可能受到地下地球化学过程的影响。本研究调查的命运U（VI）在碱性（pH值为9.6）硫酸盐还原富集培养获得高pH值的环境。为了探索U（VI）在碱性条件下的流动性，其中铁矿物是无处不在的，一系列的条件进行了测试，包括高（30 mM）和低（1 mM）碳酸盐浓度和存在和不存在的Fe（III）。在高碳酸盐浓度下，pH缓冲至约pH 9.6，这延迟了硫酸盐还原的开始，并意味着U（VI）（aq）还原为难溶性U（IV）（s）的速度减慢。低碳酸盐条件允许微生物硫酸盐还原进行，并导致pH值下降至10.7.5。pH值的下降可能是由于葡萄糖酸盐的微生物呼吸产生的挥发性脂肪酸的存在。在这里，含水硫化物积累和U从溶液中除去作为U（IV）和U（VI）磷酸盐物种的混合物。此外，硫酸盐还原菌，如Desulfosporosinus物种，在硫酸盐还原条件的发展过程中富集。结果突出了碳酸盐浓度对U的形态和溶解度在碱性条件下的影响，通知中水平放射性废物处置和放射性污染的土地管理。
Globally, the need for radioactive waste disposal and contaminated land management is clear. Here, gaining an improved understanding of how biogeochemical processes, such as Fe(III) and sulfate reduction, may control the environmental mobility of radionuclides is important. Uranium (U), typically the most abundant radionuclide by mass in radioactive wastes and contaminated land scenarios, may have its environmental mobility impacted by biogeochemical processes within the subsurface. This study investigated the fate of U(VI) in an alkaline (pH ∼9.6) sulfate-reducing enrichment culture obtained from a high-pH environment. To explore the mobility of U(VI) under alkaline conditions where iron minerals are ubiquitous, a range of conditions were tested, including high (30 mM) and low (1 mM) carbonate concentrations and the presence and absence of Fe(III). At high carbonate concentrations, the pH was buffered to approximately pH 9.6, which delayed the onset of sulfate reduction and meant that the reduction of U(VI)(aq) to poorly soluble U(IV)(s) was slowed. Low carbonate conditions allowed microbial sulfate reduction to proceed and caused the pH to fall to ∼7.5. This drop in pH was likely due to the presence of volatile fatty acids from the microbial respiration of gluconate. Here, aqueous sulfide accumulated and U was removed from solution as a mixture of U(IV) and U(VI) phosphate species. In addition, sulfate-reducing bacteria, such as Desulfosporosinus species, were enriched during development of sulfate-reducing conditions. Results highlight the impact of carbonate concentrations on U speciation and solubility in alkaline conditions, informing intermediate-level radioactive waste disposal and radioactively contaminated land management.
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DOI：
10.1073/pnas.1219198110
发表时间：
2013-03-19
影响因子：
11.1
作者：
Bargar, John R.;Williams, Kenneth H.;Bernier-Latmani, Rizlan
通讯作者：
Bernier-Latmani, Rizlan
影响因子：
11.4
作者：
Boyanov, Maxim I.;Fletcher, Kelly E.;Kemner, Kenneth M.
通讯作者：
Kemner, Kenneth M.
影响因子：
5
作者：
Belli, Keaton M.;Taillefert, Martial
通讯作者：
Taillefert, Martial
影响因子：
2.3
作者：
Beazley, Melanie J.;Martinez, Robert J.;Taillefert, Martial
通讯作者：
Taillefert, Martial
影响因子：
4.4
作者：
Anderson, RT;Vrionis, HA;Lovley, DR
通讯作者：
Lovley, DR