In a series of batch washing experiments

EDTA solution was used to remediate Cu contaminated soil derived from a Brown Field Site to investigate the removal efficiency of Cu as well as the release characteristics of major elements (Ca

Fe and so forth) by the application of six different EDTA dosages (0.10~6.00 mol/kg). Results showed that

with the increase of EDTA dosage

Cu removal efficiency was enhanced and reached a maximum at 400 mol/kg

accompanied by the decrease of Ca releasing and the increase of Fe and Al releasing. When 0.80 mol/kg EDTA was adopted

residual Cu concentration in the washed soil generally complied with the Environmental Quality Standard for Soils (Class Ⅲ) (GB156181995). When calculating the amount of metals washed by per mole EDTA

it was found that the molal ratio of metals to EDTA in the eluate decreased accordingly with the increase of EDTA addition. The maximum molal ratio of Cu/(K+Na+Ca+Mg+Fe+Al+Mn+Si)was obtained when 0.80 mol/kg EDTA was applied. However

this molal ratio decreased when the EDTA dosage was further increased

indicating that higher EDTA dosages were mainly used for the releasing of other metals. Thus

in this study

0.80 mol/kg EDTA was considered as the most appropriate dosage which could not only remediate heavy metals contaminated soil to meet the national standard

but also had the best removal efficiency of Cu when compared with other metals. Conclusively

the appropriate EDTA dosages should be determined on the basis of remediation aim

with the total metal removal efficiency and molal ratio of metals to EDTA being taken into account simultaneously.