Effect of the granulometric fractions on the fixation of zinc by soils

Abstract

This paper was carried out in order to verify the effects of the clay, silt and sand soil fractions on zinc fixation by soils. Ten grams each of 30 samples of different soils were placed in a 250 ml Erlenmeyer flask and 4 ml of solution containing 100 mg of inert Zn and 0.70 mc of radioactive 65Zn were added. After 20 days of incubation, Zn was extracted with 20 ml of 0.01 M EDTA solution made 1 M with respect to (NH4)2CO3. An aliquot of 5 ml of the extract was transferred to a test-tube and radioactivity of 65Zn in it was measured with a scintillation counter. Quantity of fixed Zn by the different soils was calculated from the data obtained and counting made on the standard solution. It was concluded that clay and silt took part of the Zn fixation by the soil, but not the sand.