title: [Sorption-desorption behaviors of Cd2+ and Pb2+ in different pollution load soils].
abstract: With batch method, this paper studied the sorption-desorption behaviors of Cd and Pb in soils with heavy, medium, and slight pollution loads. The results showed that the soil with slight pollution load had a high sorption capacity of Cd2+ and Pb2+ than the other two. For the three test soils, the isothermal curve of Cd2+ sorption fitted Freundlich equation better, while that of Pb2+ sorption could be well described with Langmuir equation and Freundlich equation. Two-constant equation was the best model to describe the sorption kinetics of Cd2+ and Pb2+, Elovich equation was the second, and the worst was first-order dynamics equation. The desorption lag of Pb2+ was more obvious than that of Cd2+, and the desorption rates of adsorbed Cd2+ and Pb2+ were higher in the soil with heavy pollution load. The relationships between the desorbed and the initial absorbed amounts of Cd2+ and Pb2+ fitted quadratic equation. In test soils, the desorption rates of Cd2+ and Pb2+ increased with increasing initial concentrations of Cd2+ and Pb2+, but decreased with increasing duration of desorpion.
authors.affiliation: Shenyang Key Laboratory of Environment Engineering, Shenyang University, Shenyang 110044, China. mailchensu@yahoo.com.cn
authors.forename: Su
authors.initials: S
authors.lastname: Chen
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Sun
authors.forename: Tie-Heng
authors.initials: TH
authors.lastname: Sun
authors.forename: Lei
authors.initials: L
authors.lastname: Chao
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000737:chemistry / Q000378:metabolism*; D004784:Environmental Monitoring / Q000379:methods; D007700:Kinetics; D007854:Lead / Q000737:chemistry / Q000378:metabolism*; D008962:Models, Theoretical; D010944:Plants / Q000378:metabolism*; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead