Mobility of Four Common Mercury Species in Model and Natural Unsaturated Soils.

Published

Journal Article

Mercury (Hg) occurs as a myriad of species in environmental media, each with different physicochemical properties. The influence of Hg speciation on its transport in unsaturated soils is not well studied. Transport of four Hg species (dissolved inorganic Hg (II) species, a prepared Hg(II) and dissolved organic matter (DOM) complex, Hg(0), and HgS nanoparticles) was measured in sand and soil packed columns with partial water saturation under simulated rainfall (low ionic strength solution without DOM) and landfill leachate (high DOM content and high ionic strength) influent conditions. The Hg(II)-DOM species had the highest mobility among the four Hg species evaluated, and HgS particles (∼230 nm hydrodynamic diameter) had the poorest mobility, for all soil and influent conditions tested. The addition of 2 wt % clay particles to sand greatly retarded the transport of all Hg species, especially under simulated rainfall. DOM in the column influent facilitated the transport of all four Hg species in model and natural soils. For simulated rainfall, the transport trends observed in model sands were consistent with those measured in a sandy soil, except that the mobility of dissolved inorganic Hg(II) species was significantly lower in natural soils. For simulated rainfall, Hg transport was negligible in a high organic content (∼3.72 wt %) soil for all species except Hg-DOM. This work suggests that the Hg-DOM species presents the greatest potential for vertical migration to groundwater, especially with DOM in the influent solution.

Full Text

Duke Authors

Cited Authors

  • Gai, K; Hoelen, TP; Hsu-Kim, H; Lowry, GV

Published Date

  • April 2016

Published In

Volume / Issue

  • 50 / 7

Start / End Page

  • 3342 - 3351

PubMed ID

  • 26949999

Pubmed Central ID

  • 26949999

Electronic International Standard Serial Number (EISSN)

  • 1520-5851

International Standard Serial Number (ISSN)

  • 0013-936X

Digital Object Identifier (DOI)

  • 10.1021/acs.est.5b04247

Language

  • eng