赖捷 邱孟琦 成建峰 冷阳春 庹先国

摘要 [目的]筛选适合污染区生长的超积累植物。[方法]采用野外采样法，以国内某核设施退役厂放射性污染区域为研究对象，测定了该区优势植物（共9科17种）和土壤中的137Cs、90Sr放射性含量，并进行了筛选与田间修复试验。[结果]污染区土壤137Cs和90Sr放射性含量的最大值分别为5.06×106和3.29×104 Bq/kg，均超过国际规定活度限值；菊科串叶草对137Cs的富集和转移系数均小于1.00，而对90Sr的富集和转移系数分别是3.25和2.95，均大于1.00；串叶草具备90Sr超积累植物特征且能修复土壤中5.9%的90Sr，可推荐串叶草对90Sr的污染土壤进行修复处理。[结论]首次发现并证实菊科串叶草是一种90Sr超积累植物，为开展污染区域修复治理工作提供参考。

关键词 铯-137；锶-90；放射性污染；植物修复技术；富集性能

Silphium perfoliatum：A New Hygrophyte with Strontium Hyperaccumulator Properties

LAI Jie1，QIU Meng-qi2，CHENG Jian-feng2，TUO Xian-guo3* et al

（1.Laboratory of National Defense for Radioactive Waste and Environmental Security， Southwest University of Science and Technology， Mianyang， Sichuan 621010；2.College of Nuclear Technology and Automation Engineering， Chengdu University of Technology， Chengdu， Sichuan 610059；3.College of Chemistry and Environmental Engineering， Sichuan University of Science&Engineering， Zigong， Sichuan 643000）

Abstract [Objective] The aim was to screen out hygrophyte with hyperaccumulator properties which could grow in pollution area.[Method] The field sampling method was adopted.On the basis of a nuclear facility decommissioning domestic factory， the content of 137Cs and 90Sr was determined in both dominant species （17 species， 9 families） and soil in polluted areas，and dominant species screening and phytoremediation tests were carried out.[Result] It was demonstrate that Silphium perfoliatum was a kind of 90Sr-hyperaccumualtor， and the maximum contents of 137Cs and 90Sr were 5.06×106 Bq/kg and 3.29×104 Bq/kg respectively， which were both above the maximum values of international regulations.The screening tests indicated that the enrichment and the transfer coefficience to 137Cs of Silphium perfoliatum were both below 1.00， while the coefficience to 90Sr were 3.25 and 2.95 respectively， which were both above 1.00.Silphium perfoliatum had the characteristic of 90Sr-hyperaccumualtor and was able to remedy 5.9% of 90Sr in the soil.[Conclusion] So Silphium perfoliatum can achieve the phytoremediation of contaminated soil with 90Sr， which can provide reference for the repair work of pollution area.

Key words 137Cs；90Sr；Radioactive contamination；Phytoremediation technology；Enrichment of performance

137Cs和90Sr是235U的裂变产物，由核设施退役、核燃料的生产与加工过程产生。137Cs可辐射β和γ射线，90Sr可释放高能β粒子，由于放射性物质会漂浮于空气中或沉降在土壤里，对食物链各级生命体造成潜在的照射危害，如果放射性物质剂量超标，将会对生物的生存环境造成巨大的威胁[1]，严重影响人类的健康[2]。由苏联的切尔诺贝利核事故可以看出，放射性核素90Sr、137Cs会對环境造成持久危害[3]。针对放射性污染如何治理，目前已进行大量的研究，例如常规的移土法[3]、客土法[4]、离子交换法[5]、氧化-还原法[6]等放射性污染治理方法，这些方法因成本高、易破坏土壤结构等缺点使其应用范围有限，但生物修复却因低成本、低扰动等特点而备受关注[7]。……