Sorption and desorption characteristics of Eu(III) on red earth

The batch method and the column method were simultaneously employed to stud y the sorption and desorption of Eu(III) on red earth as a function of pH ( 4.6-6), the presence of a well-characterized fulvic acid (FA) and the iron oxides content of red earth. The results from both methods were consistent qualitatively. The Eu(III) sorption showed significant dependences on pH an d FA, the sorption was increased with increasing pH and by addition of FA t o the solutions, while the iron oxides content of the red earth had a negat ive contribution to the sorption of Eu(III). Additionally, the sorption-des orption hysteresis of Eu(III) on red earth occurred at a pH range of 4.6-6. Therefore, the humic substance acid high pH have a great tendency to immob ilize Eu(III) on red earth.