The impact of iron nanoparticles on technetium-contaminated groundwater and sediment microbial communities.
The impact of iron nanoparticles on technetium-contaminated groundwater and sediment microbial communities.
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DOI：
10.1016/j.jhazmat.2018.10.008
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发表时间：
2019-02
影响因子：
13.6
通讯作者：
L. Newsome;K. Morris;Adrian Cleary;N. Masters-Waage;C. Boothman;N. Joshi;N. Atherton;J. Lloyd
中科院分区：
文献类型：
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作者：
L. Newsome;K. Morris;Adrian Cleary;N. Masters-Waage;C. Boothman;N. Joshi;N. Atherton;J. Lloyd
铁纳米颗粒是一种很有前途的处理受污染地下水的新技术，特别是因为它们可以被设计成优化其传输特性。锝是核设施中常见的污染物，可以通过铁（II）从地下水中还原清除。在这里，我们研究了一系列优化的铁纳米颗粒从受污染的地下水和地下水/沉积物系统中去除锝的潜力。纳米零价铁和碳铁刺激缺氧条件的发展，同时产生Fe（II），其将可溶性Tc（VII）还原为微溶的Tc（IV）。对于含Fe（II）的生物磁铁矿也观察到类似的结果，尽管速率较慢。Tc（VII）在Fe（III）矿物纳米针铁矿的存在下保持在溶液中，直到添加乙酸盐以刺激微生物Fe（III）还原，之后Tc（VII）浓度伴随Fe（II）向内生长而降低。铁纳米粒子的沉积物微宇宙的增加引起厚壁菌门的相对丰度，与发酵/缺氧代谢一致。来自生物磁铁矿纳米颗粒合成的残余细菌被沉积物微生物群落竞争。总的来说，结果表明，铁纳米颗粒在去除沉积物系统中地下水中的Tc（VII）方面非常有效，并通过刺激有益的微生物过程（包括Fe（III）还原和硫酸盐还原）产生持续的缺氧条件。
Iron nanoparticles are a promising new technology to treat contaminated groundwater, particularly as they can be engineered to optimise their transport properties. Technetium is a common contaminant at nuclear sites and can be reductively scavenged from groundwater by iron(II). Here we investigated the potential for a range of optimised iron nanoparticles to remove technetium from contaminated groundwater, and groundwater/sediment systems. Nano zero-valent iron and Carbo-iron stimulated the development of anoxic conditions while generating Fe(II) which reduced soluble Tc(VII) to sparingly soluble Tc(IV). Similar results were observed for Fe(II)-bearing biomagnetite, albeit at a slower rate. Tc(VII) remained in solution in the presence of the Fe(III) mineral nano-goethite, until acetate was added to stimulate microbial Fe(III)-reduction after which Tc(VII) concentrations decreased concomitant with Fe(II) ingrowth. The addition of iron nanoparticles to sediment microcosms caused an increase in the relative abundance of Firmicutes, consistent with fermentative/anoxic metabolisms. Residual bacteria from the synthesis of the biomagnetite nanoparticles were out-competed by the sediment microbial community. Overall the results showed that iron nanoparticles were highly effective in removing Tc(VII) from groundwater in sediment systems, and generated sustained anoxic conditions via the stimulation of beneficial microbial processes including Fe(III)-reduction and sulfate reduction.