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快速、高效、经济地清除放射性污染是核应急处置、污染场址修复的重点研究内容。从放射性污染土壤中提取、遴选出3种耐辐射真菌F3、F7和F16,研究了其对钚的吸附分离性能。3种真菌在弱酸性(pH=0.0~4.2)溶液中对钚均有较强的吸附,吸附率随溶液pH值的增大而升高。25℃下,10 m L pH值1.0溶液中10 ng/m L的钚几乎可被3种真菌完全吸附(吸附率>95%),实测F3、F7和F16对钚的平衡吸附容量分别为(11 747±539)、(17 890±757)、(11 946±477)ng/g(干菌),平衡时间约为30 min。吸附过程符合准二级动力学模型和Langmuir等温吸附模型,主要受体扩散、粒内扩散等过程控制。以0.5 mol/L的Na HCO3为解吸剂,可定量回收吸附于微生物上的钚;用3种真菌吸附回收放化实验室高盐度放射性废液中的钚,全程回收率大于99%。
Rapid, efficient and economical removal of radioactive contamination is the focus of research on nuclear emergency disposal and remediation of contaminated sites. Three kinds of radiation-resistant fungi F3, F7 and F16 were extracted from radioactive contaminated soil, and their adsorption and separation performance on plutonium was studied. The three kinds of fungi had strong adsorption of plutonium in weak acid solution (pH = 0.0 ~ 4.2), and the adsorption rate increased with the increase of solution pH. At 25 ℃, 10 ng / mL of plutonium in 10 mL of pH 1.0 solution can be almost completely adsorbed by three fungi (adsorption rate> 95%). The equilibrium adsorption capacities of F3, F7 and F16 for plutonium are ( 11 747 ± 539), (17 890 ± 757) and (11 946 ± 477) ng / g respectively. The equilibration time was about 30 min. The adsorption process accords with the quasi-second-order kinetic model and the Langmuir isothermal adsorption model, the main acceptor diffusion and the intragranular diffusion process control. With 0.5 mol / L Na HCO3 as desorbent, the plutonium adsorbed on the microorganisms can be quantitatively recovered. The recovery of plutonium from the high-salinity radioactive waste from the radiochemical laboratory with three fungi is more than 99%.