Biogeochemical behaviour of plutonium during anoxic biostimulation of contaminated sediments
Biogeochemical behaviour of plutonium during anoxic biostimulation of contaminated sediments
复制标题
污染沉积物缺氧生物刺激过程中钚的生物地球化学行为
DOI：
10.1180/minmag.2012.076.3.08
复制
发表时间：
2012
影响因子：
2.7
通讯作者：
J. Lloyd
中科院分区：
文献类型：
--
作者：
R. Kimber;C. Boothman;P. Purdie;F. Livens;J. Lloyd
了解锕系元素在环境中的生物地球化学行为对放射性核素污染土地的长期管理至关重要。钚由于其高放射性毒性、长半衰期和复杂的化学性质而特别令人关注，这些因素导致关于其环境行为的现有文献有限。在这里，我们研究了污染土壤中Pu的生物地球化学，因为微生物过程有可能通过多种机制动员Pu，包括将Pu（IV）还原为可能更具流动性的Pu（III）。在添加葡萄糖刺激微生物活动后，在第0天至第44天之间，现存微生物群落的16S rRNA基因谱发生了实质性的变化，梭状芽胞杆菌种类增加，已知的葡萄糖发酵剂促进了Pu（IV）还原为Pu（III）。第44天观察到Pu流动性略有增加，到第118天恢复到初始水平。尽管还原条件和矿物学发生了变化，但Pu迁移率的变化可以忽略不计，这表明Pu是高度难熔的。这一信息对于开发修复受铅污染土壤的方案是重要的，这表明原位管理遗留的Pu可能比通过刺激金属还原细菌动员更可取。
Abstract Understanding the biogeochemical behaviour of actinides in the environment is essential for the longterm stewardship of radionuclide contaminated land. Plutonium is of particular concern due its high radiotoxicity, long half-life and complex chemistry, with these factors contributing to the limited literature available on its environmental behaviour. Here, we investigate the biogeochemistry of Pu in contaminated soil as microbial processes have the potential to mobilize Pu through numerous mechanisms including the reduction of Pu(IV) to the potentially more mobile Pu(III). After the addition of glucose to stimulate microbial activities, there was a substantial shift in the 16S rRNA gene profile of the extant microbial communities between days 0 and 44 with an increase in Clostridium species, known glucose fermenters which have been reported to facilitate the reduction of Pu(IV) to Pu(III). A minor increase in Pu mobility was observed at day 44, returning to initial levels by day 118. The negligible change in Pu mobility, despite the onset of reducing conditions and changing mineralogy, would suggest the Pu is highly refractory. This information is important for developing remediation options for Pu-contaminated soils, suggesting that managing legacy Pu in situ may be preferred to mobilization via the stimulation of metal-reducing bacteria.