锶在土壤中的吸附动力学

    Sorption Kinetics of Strontium in Soil

    • 摘要: 用动态法测定了锶在核废物处置预选场址土壤中的平衡吸附容量,研究了水相pH值、流速、土壤粒度和锶溶液的初始质量浓度对土壤吸附锶的影响。水相pH值、流速、溶液的初始质量浓度越大,土壤平衡吸附容量越大;土壤粒度越小,土壤平衡吸附容量越大。用常用的吸附动力学方程对实验数据进行了拟合,并对吸附机理进行了探讨。实验结果表明,该放射性废物处置预选场址土壤对锶的最大吸附率为48.8%,吸附性能较差。

       

      Abstract: The sorption properties of strontium in the soil of a nuclear waste repository were investigated by column method. The effects of pH values, flux, granularities of the soil, initial mass concentration of strontium solution on the sorption properties were also studied. The equilibrium adsorptive quantities are 6.35, 8.61, 9.46, 9.73 mg/g when pH values are 4, 6, 8, 10 respectively(grain sizes: 0.178-0.840 mm,flux:60 mL/h,initial mass concentration of Sr2+:10 mg/L). The equilibrium adsorptive quantities are 9.73, 15.48, 18.26, 22.30 mg/g when the mass concentrations of Sr2+ are 10, 15, 17, 20 mg/L respectively(grain sizes: 0.178-0.840 mm,flux: 60 mL/h,pH value:10). The equilibrium adsorptive quantities are 22.22, 28.06, 39.52 mg/g when grain sizes are 0.178-0.840 mm, 0.124-0.178 mm and less than 0.124 mm(pH value:10,flux: 60 mL/h,mass concentration of Sr2+:10 mg/L).And the equilibrium adsorptive quantities are 9.37, 9.52, 10.72 mg/g when the fluxs are 60,120, 200 mL/h respectively(grain sizes : 0.178-0.840 mm, pH value:10,mass concentration of Sr2+:10 mg/L). The sorption quantities increase with the increasing of pH values, flux and the initial mass concentration of strontium solution and decrease with the increasing of the grain size of the soil.The mechanism of strontium sorption in soil was researched as well. Experimental data are analyzed with first-order kinetic equation, Elovich equation, parabola equation and double constant equation. In the four equations, Elovich equation fitts the experimental data best. The experiment results show that the maximum strontium sorption rate by the soil of the primary selected nuclear waste repository is 48.8%, and the sorption properties are not well. 

       

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