酵母菌对锕系核素239Pu的富集行为及减量化研究

为了探究微生物对锕系核素的提取分离性能，利用化学预处理和湿法消解法，初步研究了模式微生物——酵母菌(Saccharomyces cerevisiae)对中高放废液中主要锕系核素239Pu的富集减量效果研究. 结果表明:①pH=5时，活体及灭活酵母菌对239Pu的最佳吸附率均可高达99%，富集239Pu后，酵母菌经灰化处理可减量97%以上. ②经脱蛋白和脱乙酰化学预处理后，酵母菌对239Pu的吸附能力明显下降. ③随着作用时间的延长，239Pu进入胞内的比例逐渐增加，吸附96 h时，约75.64%的239Pu络合在细胞表面，约24.36%的239Pu以稳定形式在胞内外赋存；经过6批次酵母菌吸附，239Pu(Ⅲ)的放射性活度浓度从7.35×106 Bq/L梯次递降至2.30×103 Bq/L. ④针对真实中放废液，2次酵母菌吸附后，总α放射性活度浓度可降低2个数量级，总β和总γ放射性活度浓度均仅降低10%左右. 研究显示，利用酵母菌等微生物对放射性废液中锕系核素239Pu的提取和分离是可能的. 

Enrichment and Reduction of 239Pu in High and Moderate Radioactive Waste Liquid by Saccharomyces cerevisiae

In order to explore the extraction and separation performance of actinide nuclide by microorganism, the enrichment and reduction effect of model microorganism Saccharomyces cerevisiae on 239Pu of actinide nuclide in medium-high discharge waste liquor was preliminarily studied by chemical pretreatment and wet digestion method. The results showed that more than 99% of 239Pu removal could be achieved at pH 5 by living and dead S. cerevisiae with a microbial volume reduction of 97% after the ashing treatment. The adsorption ability was reduced significantly the 239Pu biosorption capacity of S. cerevisiae with deproteinization and deacetylation treatment. The wet digestion results showed that about 75.64% of 239Pu was complexed on the cell surface, while the remaining 24.36% was stabilized either inside or outside the cell after 96 h. The radioactivity of 239Pu(Ⅲ) was reduced from 7.35×106 Bq/L to 2.30×103 Bq/L after six rounds of batch adsorption of of S. cerevisiae biosorption. The total alpha radioactivity of the real medium radioactive liquid waste could be reduced by 2 orders of magnitude with more than 98% removal of the actinide nuclide content after two rounds of S. cerevisiae biosorption. However, total beta and gamma radioactivity was only be reduced by less than 10%. The presented results indicate that bio-adsorbents such as S. cerevisiae can potentially be used to extract and separate actinides from the real radioactive wastewater.