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Full-Text Articles in Earth Sciences
Readily Available Acidity In Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton
Readily Available Acidity In Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton
Associate Professor Edward D Burton
Schwertmannite and jarosite are considered as less soluble ironhydroxy sulfate minerals which are present in highly acidic environments (pH < 3). These minerals release acidity in the long run as they weather by hydrolysis [1]. However, 1M KCl extraction of soil samples (Clarence and Quartz) spiked with those two minerals showed that schwertmannite has some acidity that may be readily available.
Hydro-Geochemical Coupling In Seawater Inundation Acid Sulfate Soils: Mobilisation Of Arsenic And Hysteresis In Iron And Sulfur Cycling, Scott Johnston, Annabelle Keene, Edward Burton, Richard Bush, Leigh Sullivan
Hydro-Geochemical Coupling In Seawater Inundation Acid Sulfate Soils: Mobilisation Of Arsenic And Hysteresis In Iron And Sulfur Cycling, Scott Johnston, Annabelle Keene, Edward Burton, Richard Bush, Leigh Sullivan
Associate Professor Edward D Burton
A large-scale field trial indicates that tidal seawater inundation of coastal acid sulfate soils (CASS) stimulates iron and sulfate reducing conditions, leading to the generation of internal alkalinity and greatly decreasing soil / groundwater acidity. This remediation technique can be considered highly effective from the relatively narrow perspective of decreasing acidity and raising pH. However, a broader perspective reveals that tidal seawater inundation initiates complex and tightly coupled hydrological and geochemical processes within sediments and porewaters. These processes have had a profound effect on the mobilisation, redistribution and transformation of Fe minerals in the landscape (Johnston et al., 2011a) – …
Arsenic Mobilization And Iron Transformations During Sulfidization Of As(V)-Bearing Jarosite, Scott Johnston, Edward Burton, Annabelle Keene, Britta Planer-Friedrich, Andreas Voegelin, Mark Blackford, Greg Lumpkin
Arsenic Mobilization And Iron Transformations During Sulfidization Of As(V)-Bearing Jarosite, Scott Johnston, Edward Burton, Annabelle Keene, Britta Planer-Friedrich, Andreas Voegelin, Mark Blackford, Greg Lumpkin
Associate Professor Edward D Burton
Jarosite (KFe3(SO4) 2(OH)6) is an important host-phase for As in acid mine drainage (AMD) environments and coastal acid sulfate soils (CASS). In AMD and CASS wetlands, jarosite may encounter S(−II) produced by sulfate reducing bacteria. Here, we examine abiotic sulfidization of As(V)-bearing K-jarosite at pH 4.0, 5.0, 6.5 and 8.0. We quantify the mobilization and speciation of As and identify corresponding Fe mineral transformations. Sulfide-promoted dissolution of jarosite caused release of co-precipitated As and the majority of mobilized As was re-partitioned to a readily exchangeable surface complex (AsEx). In general, maximum As mobilization occurred in the highly sulfidized end-members of …