放射性核素污染土壤的植物提取修复技术研究关键问题探讨

在多年实际研究工作的基础上对放射性核素污染土壤的植物提取修复技术研究关键问题进行了探讨,认为超富集植物的标准既要注重植物根系从土壤中吸收核素或重金属的能力,也要注重植物生长速度及其生物量,特别要注重单位面积土壤上植物的生物量及其富集量系数。指出衡量植物修复效率的重要指标核素或重金属提取率既可用绝对量也可用相对量表示,提出了植物绝对提取率和相对提取率的概念;指出了超富集植物筛选试验方法体系,即可采用溶液培养法(水培或无土栽培)初选,污灌处理盆栽法和小区模拟试验法决选,污染区实地试验法开展试验示范及实际应用验证。提出适当确定模拟污染土壤中核素及重金属的浓度和浓度梯度;采用稳定同位素代替放射性同位素开展放射性核素对植物生长的影响、超富集植物筛选、在植物提取修复中应用超富集植物等研究是可行的。对有利于植物提取修复的强化技术及配套农业栽培技术进行了概括。

Discussion on key issues to research the phytoextraction technology of containmination of radionuclides in soil

The paper investigated the key issues to research the phytoextraction technology of containmination of radionuclides in soil on the basis of the practical work for many years. It proposed when evloving the criterion of supper-accumulation plant, capability of uptake nuclide or heavy metal from the soil, growth speed of plant and its biomass should be took into account, particularly the plant biomass on the unit areas and the coefficient of accumulation amount should been lay stress on. The paper proposed the index of ratios of absolute and relative phytoextraction and offered a proposal system of screening supper-accumulation plant. It presented solution culture (soilless cultivation) should be used for preliminary selection, sewage irrigation pot method and the plot simulation experiment for shortlist selection of supper-accumulation plant species, and then field-tested in the polluted areas to demonstration and validate. It proposed the concentration and concentration gradient of nuclide and heavy metal should be set up properly in the simulation soil of the pollution. It is viable to use stable isotope to replace the radioactive isotope in the experiment to research the effect of plant growth,screening of supper-accumulation plant species and application of supper-accumulation plant species in the phytoremediation. And it summarized the strengthen techniques and complemental agricultural cultivation techniques in favour of phytoremediation.