Time-Dependent Remobilization of Nonextractable Benzo[a]pyrene Residues in Contrasting Soils:Effects of Aging, Spiked Concentration, and Soil Properties

Umeh, Anthony C and Duan, Luchun and Naidu, Ravi and Semple, Kirk T (2018) Time-Dependent Remobilization of Nonextractable Benzo[a]pyrene Residues in Contrasting Soils:Effects of Aging, Spiked Concentration, and Soil Properties. Environmental Science and Technology, 52 (21). 12295–12305. ISSN 0013-936X

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Abstract

The environmental and health risks associated with "nonextractable" residues (NERs) of polycyclic aromatic hydrocarbons in soils and their potential for remobilization remain largely unexplored. In this novel study, sequential solvent extractions were employed to interrogate time-dependent remobilization of benzo[a]pyrene (B[a]P) NERs and associated kinetics after re-equilibration (REQ) periods lasting 30 d in four artificially spiked soils aged for up to 200 days. Following sequential extractions of the re-equilibrated soils, remobilization of B[a]P NERs was observed and further confirmed by decreases in the absolute amounts of B[a]P recovered following methanolic saponification after REQ. Remobilization may occur through slow intercompartmental partitioning of more sequestered into less sequestered B[a]P fractions in soils. The amounts of B[a]P remobilized in soils decreased throughout aging following first-order kinetics, and the rates of decrease were slow but 2 to 4 times faster than those of extractable B[a]P before re-equilibration. Sandy-clay-loam soils with large amounts of hard organic carbon exhibited less NER remobilization compared to sandy soils. The amounts of remobilized B[a]P decreased significantly ( p < 0.05) with aging. Specifically, butanol-remobilized B[a]P in soils spiked at 10 mg/kg and 50 mg/kg B[a]P ranged from 0.15 to 0.39 mg/kg and 0.67 to 2.30 mg/kg, respectively, after 200 d of aging.

Item Type:
Journal Article
Journal or Publication Title:
Environmental Science and Technology
Additional Information:
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Environmental Science and Technology, copyright 2018 © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.est.8b03008
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1600
Subjects:
ID Code:
128817
Deposited By:
Deposited On:
05 Nov 2018 09:04
Refereed?:
Yes
Published?:
Published
Last Modified:
27 Nov 2020 05:54