An increasing intensity of heavy metal contamination has caused a significant threat to human health,and has drawn more peoples attention to the serious result.Adsorption material plays an important role among the measurements removing the heavy metals in the environment.Ferrihydrite is a widespread mineral in the natural environment which is poorly crystallized with small particle size.It has large surface area and high surface activity,and also an excellent adsorption material which can affect the migration,distribution and transformation of various harmful heavy metals by adsorption.In this paper,2-line ferrihydrite was synthesized as the adsorbent to study cadmium adsorption characteristics and cadmium desorption characteristics on EDTA-2Na at normal temperature.The results show that:(1).2-line ferrihydrite can strongly adsorb Cd.(2).The XRD showed that the adsorption products were still 2-line ferrihydrite,the crystal structure had not been changed.(3).PH value is one of the significant factors that affect ferrihydrite adsorb cadmium in adsorption experiments.While low pH value varies from 3 to 5.4,adsorption capacity and removal rate of ferrihydrite on cadmium is low.As pH value increases,its adsorption capacity and removal rate grows indistinctly.It may be that there is a large number of H+ in the solution witch compete with cadmium on 2-line ferrihydrite at the low pH value,and it leads to low adsorption capacity of cadmium.While pH value varies from 5.4 to 8.5,its adsorption capacity and removal rate rises sharply as pH value increases.While pH value varies from 8.8 to 11,cadmium ions combine with hydroxide ions and Cd(OH)2 precipitate is formed.Its adsorption capacity and removal rate reach climax point and removal rate approaches one hundred percent.As pH value increases,its adsorption capacity and removal rate remain nearly unchanged and turns to stable.(4).Concentration of EDTA-2Na is one of significant factors to ferrihydrites desorbing ability of cadmium.When concentration of desorbent EDTA-2Na increases,the desorption rate of cadmium rises as well.Within different concentration of EDTA-2Na,the desorption rate of cadmium varies from 44.23%to 54.14%in desorption experiments.