Study on the Distribution and Chemical Species of Plutonium in the Contaminated Soil Particles
|Keywords||Contaminated soil Plutonium Distribution Characteristics Combined forms|
Research plutonium contaminated soil particle size distribution characteristics, is to establish the scientific basis of the imaginary class soil media plutonium contaminated site disposal options, plutonium can be suspended and preliminary analysis to the extent caused by migration to assess wind site the radiation protection of personnel to provide a reference. Study of binding forms of plutonium in the soil, to evaluate the migration of plutonium in the hypothetical situation and its biological effects, and provide the basic data for the type of soil media model of regional migration of plutonium. The study soil physical and chemical characteristics of plutonium in the soil particle size distribution characteristics of the premise, and Combined forms of plutonium reference data. Application of wet sieving and gravity settling classification device, conducted an assessment study soil texture, soil particle size distribution characteristics, the results show that: the soil texture is sandy loam. Reference GB and related reports, the establishment the ordinary soil physical and chemical properties of the measurement method, the basic physical and chemical parameters of the soil, the results show that: the soil is typical desert soil; sensible strongly alkaline, moisture content, organic matter, cation exchange capacity is very low, and ensure fertility extremely weak in the strong oxidizing conditions existing soil conditions very conducive to the growth of crops. Soil minerals primary minerals, the primary component quartz present in the coarse fraction content was decreased with the particle size decreases. Secondary minerals in the soil is mostly layered silicates, mainly present in the soil clay fraction. The soil is in the early stages of weathering. The gamma spectrometer non-destructive analysis of the plutonium content in the soil fraction, the results showed that: nearly 90% of the plutonium present in the 0.1 to 1Omm particle size, lt; 0.05mm particles of plutonium content of less than 10% of the total. Resuspended great harm to the biosphere, and therefore can not be ignored. The activity concentration of plutonium in the soil fraction gt; 45000Bq/kg, in the clean-up goals 239Pu lt; the principle of 4000Bq/kg, the ordinary wet sieving volume reduction can not be achieved under the hypothetical situation of such contaminated soil . Application Tessier et al 1979 sequential extraction of soil and soil grain-grade plutonium binding forms of content. The results showed that: exchangeable plutonium content of 0.3%, carbonate-bound plutonium content of 1.4%, 15.6% of the plutonium content of the Fe-Mn oxide, bound to organic matter plutonium content of 51.1%, the residual fraction of plutonium The content of 31.7%. The results show that the plutonium is more difficult to migrate in such geological medium. Bound to organic plutonium content of soil organic matter content in the soil linear correlation (gt; 0.1mm fraction correlation coefficient r = 0.97, lt; 0.1mm fraction correlation coefficient r = 0.74), the plutonium content in each fraction residual fraction illite content in the soil linear correlation (correlation coefficient r = 0.79). The soil fractions Am binding forms of plutonium different, but are stronger correlation with soil organic matter and illite content.