Effects of resuspension on the mobility and chemical speciation of zinc in contaminated sediments

JOURNAL OF HAZARDOUS MATERIALS

卷:364

Article

Xie, Minwei^1,2  Alsina, Marco A.^1,3  Yuen, Jeffrey^1,4  Packman, Aaron I.¹  Gaillard, Jean-Francois¹ 

[1] Northwestern Univ, Dept Civil & Environm Engn, 2145 Sheridan Rd, Evanston, IL 60208 USA

[2] Hong Kong Univ Sci & Technol, Shenzhen Res Inst, Marine Environm Lab, Shenzhen 518000, Peoples R China

[3] Univ Talca, Dept Construct Engn & Management, Fac Engn, Curico, Chile

[4] Arcadis US Inc, 200 South Michigan Ave,Suite 2000, Chicago, IL 60604 USA

关键词: Resuspension;    Contaminated sediment;    Zinc mobility;    Oxidative dissolution;    Scavenge;   

DOI  :  10.1016/j.jhazmat.2018.10.043

来源: Elsevier

【 摘 要 】

Identifying and quantifying the processes governing the mobilization of metals during resuspension events is key to assessing long-term metals efflux from sediments and associated ecological impacts. We investigated the effects of sediment resuspension on the mobilization and chemical speciation of zinc in two-week-long batch experiments using metal-contaminated sediments from Lake DePue (IL, USA). Measurements of dissolved zinc and sulfate allowed us to characterize the kinetics of metal sulfide dissolution and the resulting net release of zinc to the aqueous phase. X-ray absorption spectroscopy (XAS) provided direct insights into the chemical speciation of iron and zinc and their dynamic transformations during resuspension. While ZnS rapidly oxidized during resuspension, dissolved zinc increased only after two days of resuspension. We proposed a kinetic model to explain changes in the chemical speciation of zinc during these experiments as constrained by the dissolved species concentrations and chemical speciation as informed by XAS. Only 15% of the zinc mobilized was released to the aqueous phase while the remaining fraction repartitioned the solid phase either as a carbonate precipitate or as a sorbed species. Our results show that zinc sorption onto particle surfaces and reprecipitation of zinc minerals limit zinc solubility during resuspension of metal-sulfide sediments.

【 授权许可】

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