TOTAL SULFIDE ACIDITY FOR THE DEFINITION AND QUANTITATIVE ASSESSMENT OF THE ACID SULFATE HAZARD - SIMPLE SOLUTION OR A NEW SUITE OF PROBLEMS

Recent investigations show that the TSA (Total Sulphide Acidity) metho d for the definition and quantitative assessment of acid sulphate soil s is unreliable. Although potential acid sulphate soils do produce hig h TSA values, high TSAs may also be recorded from non-acid sulphate so ils; this problem may arise when organic matter oxidises during the hy drogen peroxide treatment to form short-chained organic acids, or when reduced iron in the soil undergoes ferrolysis. Because significant ov erestimations of acid production from non-acid sulphate soils are comm on, we recommend that the TSA procedure be abandoned as a method for a ssessing acid sulphate soils. We propose that assessment of both actua l and potential acid sulphate soils must be based on a sulphur species specific method [1].