at Google ScholarTitle data
Süß, Elke ; Planer-Friedrich, Britta:
Thioarsenate formation during oxidative dissolution of orpiment and arsenopyrite.
In: Chemosphere.
Vol. 89
(2012)
Issue 11
.
- pp. 1390-1398.
ISSN 1879-1298
DOI: https://doi.org/10.1016/j.chemosphere.2012.05.109
Abstract in another language
Thioarsenates were previously determined as dominant species in geothermal and mineral waters with excess sulfide. Here, we used batch leaching experiments to determine their formation upon weathering or industrial leaching of the arsenic-sulfide minerals orpiment (As2S3) and arsenopyrite (FeAsS) under different pH and oxygen conditions. Under acidic conditions, as expected based on their known kinetic instability at low pH, no thioarsenates formed in either of the two mineral systems. Under neutral to alkaline conditions, orpiment dissolution yielded mono-, di- and trithioarsenate which accounted for up to 43–55% of total arsenic. Thioarsenate formation upon arsenopyrite dissolution was low at neutral (4%) but significant at alkaline pH, especially under suboxic to sulfidic conditions (20–43%, mainly as monothioarsenate). In contrast to orpiment, we postulate that recombination of arsenite and sulfide in solution is of minor importance for monothioarsenate formation during alkaline arsenopyrite dissolution. We propose instead that hydroxyl physisorption lead to formation of As-OH-S surface complexes by transposition of hydroxyl anions to arsenic or iron sites. Concurrently formed ironhydroxides could provide resorption sites for the freshly released monothioarsenate. However, sorption experiments with goethite showed slower sorption kinetics of monothioarsenate compared to arsenite, but comparable with arsenate. The discovery that thioarsenates are released by natural weathering and industrial leaching processes and that, once they are released, have a higher mobility than the commonly-investigated species arsenite and arsenate requires future studies to consider them when assessing arsenic release in sulfidic natural or mining-impacted environments.
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Additional notes: | BAYCEER92224 |
| Institutions of the University: | Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences > Professor Environmental Geochemistry Group Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences > Professor Environmental Geochemistry Group > Professor Environmental Geochemistry - Univ.-Prof. Dr. Britta Planer-Friedrich Research Institutions > Research Centres > Bayreuth Center of Ecology and Environmental Research- BayCEER Faculties Faculties > Faculty of Biology, Chemistry and Earth Sciences Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences Research Institutions Research Institutions > Research Centres |
| Result of work at the UBT: | Yes |
| DDC Subjects: | 500 Science |
| Date Deposited: | 05 May 2015 12:10 |
| Last Modified: | 10 Jan 2018 09:13 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/12759 |