Stimulating the in situ activity of Geobacter species to remove uranium from the groundwater of a uranium-contaminated aquifer
Stimulating the in situ activity of Geobacter species to remove uranium from the groundwater of a uranium-contaminated aquifer
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DOI：
10.1128/aem.69.10.5884-5891.2003
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发表时间：
2003-10-01
影响因子：
4.4
通讯作者：
Lovley, DR
中科院分区：
文献类型：
--
作者：
Anderson, RT;Vrionis, HA;Lovley, DR
在科罗拉多州Rifle的一个铀污染含水层中，通过刺激异化金属还原微生物的原位活性来评估从受污染地下水中去除铀的潜力。在3个月的时间里，通过由20口注入井组成的注入通道将醋酸盐（1至3毫米）注入地下，这些注入井是由一系列15口监测井向上安装的。在开始注入乙酸酯后的短短9天内，铀（VI）浓度就下降了，在50天内，一些监测井的铀浓度降至规定的处理水平0.18 muM以下。16S核糖体DNA （rDNA）序列和磷脂脂肪酸谱分析表明，地下水中铀的初始损失与处理区内地杆菌种类的富集有关。这一时期地下水中Fe（II）也有所增加，说明U（VI）的减少与Fe（III）的减少是一致的。随着醋酸盐注射持续50天以上，地下水中硫酸盐的流失和硫化物的积累，微生物群落的组成发生了变化。与硫酸盐还原剂的16S rDNA序列最接近的生物成为优势，而地杆菌成为群落的次要组成部分。这种从Fe（III）还原到硫酸盐还原作为注入的醋酸盐氧化的终端电子接受过程的明显转变与地下水中铀浓度的增加有关。这些结果表明，铀污染地下水的原位生物修复是可行的，但建议优化策略，以更好地保持地杆菌物种的长期活性。
The potential for removing uranium from contaminated groundwater by stimulating the in situ activity of dissimilatory metal-reducing microorganisms was evaluated in a uranium-contaminated aquifer located in Rifle, Colo. Acetate (1 to 3 mM) was injected into the subsurface over a 3-month period via an injection gallery composed of 20 injection wells, which was installed upgradient from a series of 15 monitoring wells. U(VI) concentrations decreased in as little as 9 days after acetate injection was initiated, and within 50 days uranium had declined below the prescribed treatment level of 0.18 muM in some of the monitoring wells. Analysis of 16S ribosomal DNA (rDNA) sequences and phospholipid fatty acid profiles demonstrated that the initial loss of uranium from the groundwater was associated with an enrichment of Geobacter species in the treatment zone. Fe(II) in the groundwater also increased during this period, suggesting that U(VI) reduction was coincident with Fe(III) reduction. As the acetate injection continued over 50 days there was a loss of sulfate from the groundwater and an accumulation of sulfide and the composition of the microbial community changed. Organisms with 16S rDNA sequences most closely related to those of sulfate reducers became predominant, and Geobacter species became a minor component of the community. This apparent switch from Fe(III) reduction to sulfate reduction as the terminal electron accepting process for the oxidation of the injected acetate was associated with an increase in uranium concentration in the groundwater. These results demonstrate that in situ bioremediation of uranium-contaminated groundwater is feasible but suggest that the strategy should be optimized to better maintain long-term activity of Geobacter species.