title: Effect of aging on arsenic and lead fractionation and availability in soils: coupling sequential extractions with diffusive gradients in thin-films technique.
abstract: We coupled the diffusive gradients in thin-films (DGT) technique with two sequential extraction methods to investigate the influence of aging on As and Pb fractionation and availability in three soils spiked with As (40 or 400mgkg(-1)), Pb (150 or 1500mgkg(-1)) or As+Pb (40mgkg(-1) As and 150mgkg(-1) Pb). During aging, As moved from the more available (non-specifically and specifically sorbed) to less available (amorphous and crystallized Fe/Al) fractions while Pb moved from the first three fractions (exchangeable, carbonate and Fe/Mn hydroxide) to organic fraction. However, even after 33-week aging, much more As and Pb were in the least available residual fraction in spiked soils than native soils (11-59% vs. 1.2-12%). Relatively, As in spiked soils was much more available than Pb with 11-14% As and 46-59% Pb in the residual fraction. Correlation analysis indicated that As in the non-specifically and specifically sorbed fractions and Pb in the exchangeable fraction were likely sources of DGT-measured labile As and Pb. The fact that As and Pb distribution and availability in spiked soils were significantly different from native soils suggests caution needs to be exercised when using spiked soils for research.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China.
authors.forename: Dong-Xing
authors.initials: DX
authors.lastname: Guan
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China.
authors.forename: Jing-Hua
authors.initials: JH
authors.lastname: Ren
authors.affiliation: College of Resources and Environment, Shandong Agricultural University, Shangdong 271018, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China. Electronic address: esluojun@nju.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210023, China; Soil and Water Science Department, University of Florida, Gainesville, FL 32611, USA. Electronic address: lqma@ufl.edu.
authors.forename: Lena Q
authors.initials: LQ
authors.lastname: Ma
mesh_terms: D001151:Arsenic / Q000737:chemistry*; D005591:Chemical Fractionation; D004058:Diffusion; D007854:Lead / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D007854:Lead; D001151:Arsenic
keywords: Aging; Arsenic; Diffusive gradients in thin films; Lead; Sequential extraction