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Full-Text Articles in Physical Sciences and Mathematics
The Response Of Partially Oxidised Acid Sulfate Soil Materials To Anoxia, Nicholas Ward, Leigh Sullivan, Richard Bush
The Response Of Partially Oxidised Acid Sulfate Soil Materials To Anoxia, Nicholas Ward, Leigh Sullivan, Richard Bush
Dr Nicholas J Ward
Four acid sulfate soil (ASS) materials were subjected to anoxia after varying periods of oxidation to determine the geochemical response of these types of soils to flooding. The response of the partially oxidised ASS materials to the exclusion of oxygen was variable. The rate of sulfide oxidation, acidification, and the production of soluble oxidation products such as sulfate, iron, and aluminium generally decreased markedly when subjected to anoxia. However, especially in the highly acidic ASS materials (i.e. pH 3+. Rapid sulfide re-formation occurred in the peat ASS material that had been oxidised for 63 days, with 0.47% reduced inorganic sulfur …
Sulfide Oxidation In Some Acid Sulfate Soil Materials, Nicholas John Ward
Sulfide Oxidation In Some Acid Sulfate Soil Materials, Nicholas John Ward
Dr Nicholas J Ward
This thesis examines sulfide oxidation in 4 physically and mineralogically diverse acid sulfate soil (ASS) materials collected from coastal floodplain sites in north-eastern New South Wales. The aim of this study is to gain further understanding of the process of sulfide oxidation in ASS materials, which will allow improved and more effective management strategies to be applied to these materials. The process of sulfide oxidation was examined using laboratory incubation experiments. The oxidation of pyrite was the primary cause of initial acidification of the ASS materials studied. Although the acid volatile sulfur fraction increased in concentration by an order of …
Soil Ph, Oxygen Availability, And The Rate Of Sulfide Oxidation In Acid Sulfate Soil Materials: Implications For Environmental Hazard Assessment, Nicholas Ward, Leigh Sullivan, Richard Bush
Soil Ph, Oxygen Availability, And The Rate Of Sulfide Oxidation In Acid Sulfate Soil Materials: Implications For Environmental Hazard Assessment, Nicholas Ward, Leigh Sullivan, Richard Bush
Dr Nicholas J Ward
The potential environmental hazard of acid sulfate soil (ASS) materials is directly related to both the net acidity and the rate that actual acidity is released from these soil materials into the environment. While current environmental hazard assessment techniques for ASS materials are able to quantify the net acidity, they do not take account of differences in the rate of sulfide oxidation (the dominant source of actual acidity) and differences in the rate of acidification. In this study the rate of sulfide oxidation during incubation was examined for 4 ASS materials. The effect of pH and oxygen availability on the …
The Process Of Sulfide Oxidation In Some Acid Sulfate Soil Materials, Nicholas Ward, Leigh Sullivan, Diane Fyfe, Richard Bush, Angus Ferguson
The Process Of Sulfide Oxidation In Some Acid Sulfate Soil Materials, Nicholas Ward, Leigh Sullivan, Diane Fyfe, Richard Bush, Angus Ferguson
Dr Nicholas J Ward
The process of sulfide oxidation in acid sulfate soils (ASS) is complex, involving the formation of numerous oxidation products. In this study the sulfide oxidation process was examined in 2 ASS materials over a period of 36 days using laboratory incubation experiments. Both ASS materials experienced substantial sulfide oxidation and acidification during incubation. The oxidation of pyrite was the primary cause of acidification in these ASS materials. Although a decrease in magnetic susceptibility (χ) over the initial 4 days of incubation suggested the rapid oxidation of ferromagnetic iron monosulfide greigite (Fe3S4), the total acid volatile sulfur …