Anion Elution Patterns from Soils and Soil Clays

Abstract The leaching of Cl ‐ and SO 4 = ions through columns of whole soil and soil clay was investigated by adding salts to the top layers, eluting with water, and measuring ion concentrations in column eluates. A “normal” anion elution curve with a distribution coefficient of 1 was interpreted as indicating no anion attraction to the soil. Deviations from a “normal” curve resulting in a skewed elution pattern were interpreted as indicating anion attraction. Creedmoor clay, with a high negative charge, attracted neither Cl ‐ nor SO 4 = . Cecil clay and Cecil and Appling soils, which have low negative charges and are high in kaolin and oxides of aluminum and iron, gave asymmetric anion elution curves at lower pH values, indicating anion attraction. Cecil clay pre‐leached with HNO 3 retained both SO 4 = and Cl ‐ against moderate leaching, however, under less acid conditions (pH 4 to 6) only SO 4 = was retained.