有机配体EDTA对土壤吸附和解吸稀土元素行为的影响

研究了有机配体EDTA对土壤吸附和解吸稀土元素La、Gd、Y的影响．结果表明，吸附作用在加入有机配体和稀土元素后0.5h便达到平衡，当存在单一稀土元素时，土壤对La、Gd、Y吸附量随EDTA浓度增加而减少，而在混合稀土元素条件下，土壤对各稀土元素的吸附与稀土－EDTA配合物稳定常数呈负相关，并且观察到竞争吸附现象．EDTA可促进稀土元素从土壤中解吸下来，解吸量与EDTA配体浓度呈正相关，其相关方程可用 1nX＝n 1n c＋1nK来描述

The effects of organic ligand EDTA on the absorption and desorption of rare earth elements in soil.

The effects of organic ligand EDTA on adsorption and desorption of rare earth elements (La. Gd. Y) in soil were investigated. The results showed that adsorption equilibrium was reached in 0.5h after the addition of the rare earth elements and EDTA; the adsorpiton amounts of La. Gd. Y by soil decreased with increasing the concentration of EDTA in single rare earth solution; and the adsorption amount of each rare earth element by soils was negatively correlated with the stability constants of rare earth-EDTA complexes in mixed rare earth solution. A competetive adsorption was observed in the processes. EDTA could promote the desorption of rare earth elements from soil; and it presented positive relationship between desorption amounts of from soils and the concentration of EDTA. The relative equation can be described as lnX = n lnc lnK.