Role of organic acids in promoting colloidal transport of mercury from mine tailings
Environmental Science & Technology
By: A.J. Slowey, S.B. Johnson, J. J. Rytuba, and Gordon E. Brown Jr.
Links
- More information: Publisher Index Page (via DOI)
- Download citation as: RIS | Dublin Core
Abstract
A number of factors affect the transport of dissolved and paniculate mercury (Hg) from inoperative Hg mines, including the presence of organic acids in the rooting zone of vegetated mine waste. We examined the role of the two most common organic acids in soils (oxalic and citric acid) on Hg transport from such waste by pumping a mixed organic acid solution (pH 5.7) at 1 mL/min through Hg mine tailings columns. For the two total organic acid concentrations investigated (20 ??M and 1 mM), particle-associated Hg was mobilized, with the onset of paniculate Hg transport occurring later for the lower organic acid concentration. Chemical analyses of column effluent indicate that 98 wt % of Hg mobilized from the column was paniculate. Hg speciation was determined using extended X-ray absorption fine structure spectroscopy and transmission electron microscopy, showing that HgS minerals are dominant in the mobilized particles. Hg adsorbed to colloids is another likely mode of transport due to the abundance of Fe-(oxyhydr)oxides, Fe-sulfides, alunite, and jarosite in the tailings to which Hg(II) adsorbs. Organic acids produced by plants are likely to enhance the transport of colloid-associated Hg from vegetated Hg mine tailings by dissolving cements to enable colloid release. ?? 2005 American Chemical Society.
Suggested Citation
Slowey, A., Johnson, S., Rytuba, J.J., Brown, G.E., 2005, Role of organic acids in promoting colloidal transport of mercury from mine tailings: Environmental Science & Technology, v. 39, no. 20, p. 7869-7874, https://doi.org/10.1021/es0504643.
ISSN: 1520-5851 (online)
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Role of organic acids in promoting colloidal transport of mercury from mine tailings |
| Series title | Environmental Science & Technology |
| DOI | 10.1021/es0504643 |
| Volume | 39 |
| Issue | 20 |
| Publication Date | September 09, 2005 |
| Year Published | 2005 |
| Language | English |
| Larger Work Type | Article |
| Larger Work Subtype | Journal Article |
| Larger Work Title | Environmental Science and Technology |
| First page | 7869 |
| Last page | 7874 |