title: Mobility and attenuation of arsenic in sulfide-rich mining wastes from the Czech Republic.
abstract: The mineralogical composition of mining wastes deposited in countless dumps around the world is the key factor that controls retention and release of pollutants. Here we report a multi-method data set combining mineralogical (X-ray diffraction, electron microprobe and Raman microspectrometry) and geochemical (sequential extraction and pore water analysis) methods to resolve As mobility in two 50-years-old mining waste dumps. Originally, all of the As in the mining wastes selected for the study was present as arsenopyrite and with time it has been replaced by secondary As phases. At Jedová jáma mining area, the most of As precipitated as X-ray amorphous ferric arsenate (HFA). Arsenic is also accumulated in the scorodite and Fe (hydr)oxide (with up to 3.2wt.% As2O5) that is particularly represented by hematite. Mining wastes at Dlouhá Ves contain only trace amount of scorodite. Arsenic is primarily bound to Pb-jarosite and Fe (hydr)oxides (especially goethite) with up to 1.6 and 1.8wt.% As2O5, respectively. The pore water collected after rainfall events indicated high concentrations of As (~4600μg·L(-1)) at Jedová jáma, whereas aqueous As at Dlouhá Ves was negligible (up to 1.5μg·L(-1)). Highly mobile As at Jedová jáma is attributed to the dissolution of HFA and simultaneous precipitation of Fe (hydr)oxides under mildly acidic conditions (pH~4.4); immobile As at Dlouhá Ves is due to the efficient adsorption on the Fe (hydr)oxides and hydroxosulfates under acidic pH of ~2.8. Taken together, As mobility in the ferric arsenates-containing mining wastes may significantly vary. These wastes must be kept under acidic conditions or with high aqueous Fe(III) concentrations to prevent the release of As from incongruent dissolution of ferric arsenates.
authors.affiliation: Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic. Electronic address: petr.drahota@natur.cuni.cz.
authors.forename: Petr
authors.initials: P
authors.lastname: Drahota
authors.affiliation: Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic.
authors.forename: Magdaléna
authors.initials: M
authors.lastname: Knappová
authors.affiliation: Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic.
authors.forename: Helena
authors.initials: H
authors.lastname: Kindlová
authors.affiliation: Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic.
authors.forename: Adam
authors.initials: A
authors.lastname: Culka
authors.affiliation: Institute of Geosciences, Friedrich-Schiller University, Burgweg 11, D-07749 Jena, Germany.
authors.forename: Juraj
authors.initials: J
authors.lastname: Majzlan
authors.affiliation: Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Mihaljevič
authors.affiliation: Institute of Geology, The Czech Academy of Sciences, v.v.i., Rozvojová 269, 165 00 Prague 6, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Rohovec
authors.affiliation: Czech Geological Survey, Geologická 6, 152 00 Prague 5, Czech Republic.
authors.forename: František
authors.initials: F
authors.lastname: Veselovský
authors.affiliation: Institute of Geology, The Czech Academy of Sciences, v.v.i., Rozvojová 269, 165 00 Prague 6, Czech Republic.
authors.forename: Michaela
authors.initials: M
authors.lastname: Fridrichová
authors.affiliation: Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6, 128 43 Prague 2, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Jehlička
keywords: Arsenic; Mining waste; Mobility; Pore water; Secondary arsenic minerals