title: [Sorption behaviors of BDE-28 on natural soils].
abstract: The sorption kinetics and isotherms of BDE-28 on three natural soils with different soil organic matter fractions (f(oc)) were investigated. The results indicated that a two (fast and slow)-compartment first-order model was more appropriate for describing the sorption kinetic data, compared to a one-compartment first-order model, especially in the initial sorption stage within 25 h. The fast sorption was predominant during the whole sorption process from beginning to the apparent sorption equilibrium; while the contribution of the slow sorption to the total sorption amount gradually increased and then achieved a plateau at 49 h or 55 h. The approaching time to the individual sorption capacity for the fast sorption was much shorter than that for the slow sorption. The contribution of the fast sorption to the increase in the total sorption amount of BDE-28 was prevailing at the beginning of sorption process from 2.5 h to 4.5 h; whereas the fraction of the slow sorption became primary at the subsequent stage of sorption process. The fitting results by the Dubinin-Ashtakhov (DA) model were comparable with those by the Freundlich model in the range of apparent equilibrium concentration studied. As for the Freundlich model, the nonlinear exponent (n) values of BDE-28 for the two samples with lower f(oc) (0.72%) or higher f(oc) (7.90%) approached to 1.0 (1.03 +/- 0.05 and 1.00 +/- 0.05, respectively), suggesting the linear sorption characteristics in the studied range of apparent equilibrium concentrations of BDE-28; while the nonlinear behavior of BDE-28 for the left sample with medium f(oc) (4.42%) was indicated by its n value less than 1.0 (0.89 +/- 0.04).
authors.affiliation: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China. wxliu@urban.pku.edu.cn
authors.forename: Wen-Xin
authors.initials: WX
authors.lastname: Liu
authors.forename: Xi
authors.initials: X
authors.lastname: Ling
authors.forename: Jiang-Lin
authors.initials: JL
authors.lastname: Chen
authors.forename: Wei-Bo
authors.initials: WB
authors.lastname: Li
authors.forename: Han
authors.initials: H
authors.lastname: Dou
authors.forename: Shu
authors.initials: S
authors.lastname: Tao
mesh_terms: D000327:Adsorption; D004785:Environmental Pollutants / Q000302:isolation & purification* / Q000378:metabolism; D008962:Models, Theoretical; D011075:Polybrominated Biphenyls / Q000302:isolation & purification* / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D011075:Polybrominated Biphenyls; D012987:Soil; D012989:Soil Pollutants; C533760:tribromodiphenyl ether 28