放射性核素~(60)Co在土壤中吸附和解吸的动力学研究

应用同位素示踪技术,研究了60Co在小粉土、黄红壤、青紫泥和海泥中的吸附和解吸。结果表明,60Co进入淹水土壤之后,迅速地被土壤吸附而达到吸附平衡,不易解吸。吸附率和分配系数大小排列顺序均为:海泥>青紫泥>黄红壤>小粉土;解吸因数的大小排列顺序为:黄红壤>小粉土>青紫泥>海泥6。0Co在土壤中的动态变化可用封闭二分室进行描述,其动态变化规律为,小粉土C1=1 382.6(1-e-3.609 5t),黄红壤C2=1 570.6(1-e-5.510 4t),青紫泥C3=1 594.9(1-e-7.554 1t),海泥C4=1 643.9(1-e-13.092 1t)。

Kinetic Research on Adsorption and Desorption of Cobalt-60 in Soils

The isotopic tracer technique was applied to study the adsorption and desorption of cobalt-60 in paddy soil on powdery loam,yellow-red earth,paddy soil on blue purple clay and sea clay.The results show that after cobalt-60 entered into the flood soil,it was quickly adsorped by soil and reached the adsorption equilibrium,but it was difficult to be desorbed.The order of the saturated adsorption rate and K_d(distribution coefficient) of cobalt-60 at the balance value was:sea clay>puddy soil on blue purple clay>yellow-red earth>paddy soil on powdery loam.The order of D_f(desorption factor) value is:yellow-red earth>paddy soil on powdery loam>puddy soil on blue purple clay>sea clay.The dynamic behavior of cobalt-60 in the soils can be described by a closed two-compartment model and C_1=1 382.6(1-e~(-3.609 5t)) for paddy soil on powdery loam,C_2=1 570.6(1-e~(-5.510 4t)) for yellow-red earth,C_3=1 594.9(1-e~(-7.554 1t)) for paddy soil on blue purple clay,C_4=1 643.9(1-e~(-13.092 1t)) for sea clay,respectively.