Sorption Kinetics of Strontium in Soil

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. 