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- Acid sulfate soils (2)
- Arsenic (2)
- Fulvic acid (2)
- Schwertmannite (2)
- AAO (1)
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- ABA (1)
- Acid based account (1)
- Acid based account (ABA) (1)
- Acid sulphate soils (1)
- Acidified (1)
- Acidified ammonium oxalate (1)
- Acidity (1)
- Aerobic-acidic water (1)
- Ammonium oxalate method (AAO) (1)
- Anaerobic-reducing sediments (1)
- Coastal acid sulfate soils (1)
- DXRD (1)
- Differential X-ray diffraction (1)
- Differential x-ray diffraction (DXRD) (1)
- Fe/S molar ratio (1)
- Fe2+ catalysed transformation (1)
- Iron hydroxy-sulfate minerals (1)
- Jarosite (1)
- Microbial reductive dissolution (1)
- RA (1)
- Rainfall (1)
- Retained acidity (1)
- Retained acidity (RA) (1)
- SNAS (1)
- SNAS methods (1)
Articles 1 - 6 of 6
Full-Text Articles in Earth Sciences
Acidity Fractions In Acid Sulfate Soils And Sediments: Contributions Of Schwertmannite And Jarosite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton
Acidity Fractions In Acid Sulfate Soils And Sediments: Contributions Of Schwertmannite And Jarosite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton
Chamindra Vithana
In Australia, the assessment of acidity hazard in acid sulfate soils requires the estimation of operationally defined acidity fractions such as actual acidity, potential sulfidic acidity, and retained acidity. Acid–base accounting approaches in Australia use these acidity fractions to estimate the net acidity of acid sulfate soils materials. Retained acidity is the acidity stored in the secondary Fe/Al hydroxy sulfate minerals, such as jarosite, natrojarosite, schwertmannite, and basaluminite. Retained acidity is usually measured as either net acid-soluble sulfur (SNAS) or residual acid soluble sulfur (SRAS). In the present study, contributions of schwertmannite and jarosite to the …
Liberation Of Acidity And Arsenic From Schwertmannite: Effect Of Fulvic Acid, Chamindra Vithana, Leigh Sullivan, Edward Burton, Richard Bush
Liberation Of Acidity And Arsenic From Schwertmannite: Effect Of Fulvic Acid, Chamindra Vithana, Leigh Sullivan, Edward Burton, Richard Bush
Chamindra Vithana
Schwertmannite is one of the major components that produces acidity in acid mine drainage (AMD) and acid sulfate soils (ASS) and is also known to be an effective scavenger of Arsenic (As) in such environments. Fulvic acid (FA) is an active component of natural organic matter (NOM) and is known to interact strongly with both schwertmannite and As. Two main environmental hazards related to schwertmannite are acidity liberation and potential re-mobilization of adsorbed or co-precipitated As upon hydrolysis. This study focused on understanding the behaviour of As-substituted schwertmannite with regard to the potential of acidity liberation, the effect of FA …
Jarosite Quantification In Soils: An Enhanced Sequential Extraction Procedure, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton
Jarosite Quantification In Soils: An Enhanced Sequential Extraction Procedure, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton
Chamindra Vithana
A two-step sequential extraction procedure established for the quantification of acidity producing ferric and ferrous sulfate minerals such as melanterite and jarosite in acid mine wastes was evaluated for quantification of jarosite spiked in soils. The procedure involves in sequence anoxic water extraction, roasting the solid residue after anoxic water extraction at 550 °C for 1 h, and 4 M HCl extraction of the roasted solid. Soil and quartz samples were spiked with known amounts of synthetic and natural jarosite and their recovery was measured using the suggested two-step sequential extraction procedure. The recoveries of synthetic and natural jarosite were …
Assessment And Behaviour Of Secondary Iron(Iii) Minerals In Acid Sulphate Soil Materials, Chamindra Vithana
Assessment And Behaviour Of Secondary Iron(Iii) Minerals In Acid Sulphate Soil Materials, Chamindra Vithana
Chamindra Vithana
This study examined two aspects of acidity generating secondary Fe(III) minerals (i.e. schwertmannite and jarosite) in acid sulfate soils (ASS) environments: i) accurate identification and quantification, and ii) improving our understanding of their behaviour in ASS.The study showed that current assessment methods have a number of limitations and are not reliable for accurate estimation of both minerals in ASS environments. The study also showed that in natural environments, these minerals can behave in a manner different to current conceptual understanding. The broad implication of this study was identification of the need for development of improved management techniques for ASS.
Schwertmannite In Soil Materials: Limits Of Detection Of Acidified Ammonium Oxalate Method And Differential X-Ray Diffraction, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton
Schwertmannite In Soil Materials: Limits Of Detection Of Acidified Ammonium Oxalate Method And Differential X-Ray Diffraction, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton
Chamindra Vithana
Schwertmannite is a secondary iron mineral, found in acid mine drainage (AMD) and acid sulfate soils (ASS), that generates acidity when it transforms to stable mineral phases. Acidity liberated during schwertmannite transformation can seriously diminish water quality and soil health. Acidified ammonium oxalate (AAO) extraction in the dark coupled with differential X-ray diffraction (DXRD) analysis is routinely used to identify and to quantify poorly crystalline iron oxide phases such as schwertmannite in AMD environments. However, management of ASS environments is largely impacted due to lack of reliable methods to identify/quantify schwertmannite in soil materials. Our study aimed to evaluate the …
Stability Of Schwertmannite And Jarosite In An Acidic Landscape: Prolonged Field Incubation, Chamindra Vithana, Leigh Sullivan, Edward Burton, Richard Bush
Stability Of Schwertmannite And Jarosite In An Acidic Landscape: Prolonged Field Incubation, Chamindra Vithana, Leigh Sullivan, Edward Burton, Richard Bush
Chamindra Vithana
Schwertmannite and jarosite are two of the main secondary iron(III) minerals commonly found in acidic, iron and sulfate-rich environments such as acid mine drainage and coastal acid sulfate soils (CASS). Both minerals exert major influence on the water and soil quality in these environments.While there are many studies conducted on the stability of these two minerals under controlled laboratory conditions, the behaviour of schwertmannite and jarosite under field conditions and the factors influencing their behaviour have not been investigated directly. In the present study, we examined the net transformation of introduced schwertmannite and jarosite samples incubated in a typical acidic …