The Applications of Chemical Analyses of Sediments and Soils in ...

Pyritic sulphur content, measured after leaching out sulphate and carbonates ismost important in the consideration of toxicity or potential toxicity from acidity.Acid Potential of soils has been determined by hydrogen peroxide oxidation(Brinkman and Pons, 1972). If the sample is pretreated to remove carbonate andsulphate, a strong correlation (r 2 = 0.970) was found between acidity and per centsulphur (Smith et al, 1974).The Acid Potential of powdered coal, and probably other materials, can bemeasured under carefully controlled laboratory conditions in the absence ofmicro-organisms using distilled water in a heated Soxhlet extractor and a peristalticpump (Smith et al, 1974).Determination of Neutralization Potential is important in the evaluation of minesoils and can best be measured by acid titration using a modification of Jackson'smethod (Jackson, 1958; Smith et al, 1974) The Woodruff buffer method (Woodruff,1948) has been found satisfactory in determining the immediate lime requirement ofacid mine spoils in West Virginia (West Virginia University, 1971). However, if there isappreciable sulphide, such as pyrites, and there are insufficient bases present as shownby the Neutralization Potential, the lime requirement can be estimated from per centsulphur (Smith et al, 1974). Stoichometrically, for 0.1 per cent sulphur as FeS 2 , 6250lb. calcium carbonate are required to neutralize 1000 tons material.The Term Net Potential Deficiency (Smith et al, 1974) has been used, expressed29