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Dr Nicholas J Ward

2013

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Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Sulfide Oxidation And Acidification Of Acid Sulfate Soil Materials Treated With Caco3 And Seawater-Neutralised Bauxite Refinery Residue, Nicholas Ward, Leigh Sullivan, Richard Bush Oct 2013

Sulfide Oxidation And Acidification Of Acid Sulfate Soil Materials Treated With Caco3 And Seawater-Neutralised Bauxite Refinery Residue, Nicholas Ward, Leigh Sullivan, Richard Bush

Dr Nicholas J Ward

Acid sulfate soil (ASS) materials that are subject to oxidation are often treated with neutralising agents to minimise the export of acidity that may result from pyrite oxidation. The effects of additions of both CaCO3 and seawater-neutralised bauxite refinery residue (SNBRR) on the oxidation of sulfides and acidification were assessed for 4 ASS materials using laboratory incubation experiments. As the application of sub-optimal rates of neutralising materials can occur for a variety of reasons, the effect of application rates were also examined. Two application rates were chosen; a sub-optimal rate [approximately 20% of the theoretical neutralising requirement (NR)] and …


Sulfide Oxidation In Some Acid Sulfate Soil Materials, Nicholas John Ward Oct 2013

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 …