Keywords: 
• soil /
• POPs /
• pesticide /
• thermal desorption /
• remediation /
• physicochemical properties

Abstract: Soil sample collected from a POPs pesticide-contaminated site in Beijing was treated with thermal desorption to investigate the efficiency of POPs removal and cultivability of the treated soil. Both residues of compositions of DDTs/HCHs and change of physic-chemical properties of the treated soil were examined at different temperatures. The results showed that thermal desorption could eliminate DDTs and HCHs in the soils effectively. Removal efficiencies of p，p′-DDE and α-HCH were affected by temperature more seriously than others. More than 97%、99% of ∑HCH and ∑DDT could be removed from soil at 310℃ and 340℃， respectively， and the residue met Standard of Soil Quality Assessment for Exhibition Sites， and the removal rate did not increase apparently thereafter. Changes of physic-chemical properties of the soils after thermal desorption varied depending on the degree of thermal desorption temperatures. SOM and TN decreased from 0.78%， 0.0352% to 0.14%， 0.0107%， respectively； pH fluctuated from 7.80 to 8.25； CEC decreased from 7.87 mg/kg to 5.00 mg/kg. However， rapid available phosphorus increased significantly， from 7.59 mg/kg to 21.8 mg/kg. With optimum temperature， acceptable change of physic-chemical properties of the treated soils can be obtained. These results suggest that thermal desorption is an effective method for POPs-contaminated soil treatment， and process with suitable temperature has less effects on physic-chemical properties of the treated soil. Therefore， thermal desorption is potentially a green remediation technology.