Reductive Dissolution of Jarosite by Acidiphilium cryptum in Presence of Chelating Agents and Dissolved Iron

Abstract

The mutual effects of Acidiphilium cryptum, nine ligands and dissolved iron on jarosite dissolution were studied in a 2 3 full factorial experiment. Ethylenediaminetetraacetic (EDTA), nitrilotriacetic (NTA) and oxalic acids were able to dissolve jarosite chemically, but bacterial action enhanced this dissolution; from 88±1, 46±0 and 36±0 µmol/L·d to 129±3, 177±5 and 106±14 µmol/L·d, respectively. Oxalate and NTA exhibited a synergistic effect with dissolved iron and bacteria that may be explained by a model in which iron complexes behave as redox mediators in the microbial respiration in which jarosite, a solid substrate, serves as terminal electron acceptor.

Iron‑sulfur geochemistry and acidity retention in hydrologically active macropores of boreal acid sulfate soils: Effects of mitigation suspensions of fine-grained calcite and peat

“…These treatment-induced conditions are outside the stability range of jarosite, thus favoring its dissolution and hydrolysis, in line with the absence of this mineral in all treated columns (Table 2). It has also been shown that chelating agents (e.g., organic ligands) could enhance the dissolution of jarosite either chemically or in combination with microbial activities (González et al, 2017;Tang et al, 2020;Trueman et al, 2020). Such processes might have facilitated the dissolution of jarosite in the peattreated columns (P, C 2.5 P, and C 0.3 P), one of which (P) showed only a weak increase in pH (Högfors-Rönnholm et al, 2022).…”

Oxidative Dissolution of Sulfide Minerals in Single and Mixed Sulfide Systems under Simulated Acid and Metalliferous Drainage Conditions

“…EDTA extraction has been used to dissolve metal ions in adsorbed, oxide, hydroxide, or sulfate forms (e.g., Pb and Zn precipitates) to provide an estimate of the extent of sulfide mineral oxidation. 29,30 EDTA has previously been found to dissolve jarosite 31 and waterinsoluble Pb sulfate (see Supporting Information, S3 in the work by Qian et al 2018 27 ). Previous studies have also indicated that EDTA can dissolve metals adsorbed on material surfaces (see the works by Ding et al 32 and Peters 33 and references therein).…”

“…The general nomenclature “dissolution” or “dissolved” used in this paper to describe the dissolution of sulfide minerals includes the formation of solution species, secondary precipitates, and oxidized nonaqueous polysulfide and elemental sulfur species. EDTA extraction has been used to dissolve metal ions in adsorbed, oxide, hydroxide, or sulfate forms (e.g., Pb and Zn precipitates) to provide an estimate of the extent of sulfide mineral oxidation. , EDTA has previously been found to dissolve jarosite and water-insoluble Pb sulfate (see Supporting Information, S3 in the work by Qian et al 2018). Previous studies have also indicated that EDTA can dissolve metals adsorbed on material surfaces (see the works by Ding et al and Peters and references therein).…”

Chemical and Reactive Transport Processes Associated with Hydraulic Fracturing of Unconventional Oil/Gas Shales

“…The presence of chelating agents can have a dual role based on the chelator used. Numerous chelating agents can aid in the redox transition of Fe, both oxidative and reductive, depending on solution conditions. − Another class of Fe chelators, siderophores, generally inhibit redox transitions in Fe complexes . This shows the importance of organics in Fe redox chemistry at solution conditions in which inorganic Fe oxidation is extremely slow.…”