土壤中吸附和解吸^(95)Zr的动力学研究

Kinetic research on adsorption and desorption of Zirconium-95 in soils

应用同位素示踪技术 ,研究了 95Zr在小粉土、黄红壤、青紫泥和海泥中的吸附和解吸。结果表明 ,95Zr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、小粉土、黄红壤 ;解吸因数的大小排列顺序为 :黄红壤、小粉土、青紫泥、海泥。95Zr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 =1 474.7(1 -e- 3.52 75t) ,黄红壤 C2 =1 481 .6(1 -e- 2 .7535t) ,青紫泥 C3=1 5 70 .6(1 -e- 5.4 1 0 4 t) ,海泥 C4 =1 75 0 .8(1 -e- 9.71 95t)

The isotopic tracer technique is applied to study the adsorption and desorption of zirconium 95 in paddy soil on powdery loam, yellow red earth, paddy soil on blue purple clay and sea clay, the results show that after zirconium 95 entered into the flood soil, it was quickly adsorped by soil and reached the adsorption equilibrum, and desorped difficultly. The order of the saturated adsorption rate and K d (distribution coefficient) of zirconium 95 at the balance value is: sea clay, puddy soil on blue purple clay, paddy soil on powdery loam, yellow red earth. 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 zirconium 95 in the soils can be described as a closed two compartment model. The law of dynamic change was, C 1=1474.7(1 e -3.5275t ) for paddy soil on powdery loam, C 2=1481.6(1 e -2.7535t ) for yellow red earth, C 3=1570.6(1 e -5.4104t ) for paddy soil on blue purple clay, C 4=1750.8(1 e -9.7195t ) for sea clay.