Physical Sciences and Mathematics Commons^™

Acidity Fractions In Acid Sulfate Soils And Sediments: Contributions Of Schwertmannite And Jarosite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Associate Professor Edward D Burton

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 (S_NAS) or residual acid soluble sulfur (S_RAS). 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

Associate Professor Edward D Burton

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 …

Effect Of Fulvic Acid On Liberation Of Acidity And Arsenic Form Arsenic Substituted Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Associate Professor Edward D Burton

INTRODUCTION

Schwertmannite is one of the main secondary iron hydroxy sulfate minerals contributing to acidity in acid sulfate soils (ASS). While it is an important source of acidity in ASS, schwertmannite is also known to be a potential sink for trace metals such as arsenic (As) and chromium (Cr) (Fukushi et al. 2003; Regenspurg and Peiffer. 2005).Trace metal adsorption/substitution is known to stabilize schwertmannite which in turn retards its transformation to goethite which is one of the main processes of acidity generation in ASS. Fulvic Acid (FA) is a subclass of natural organic materials that are ubiquitous in aquatic environments …