The Study of Soluble and Exchangeable and Bounded to Carbonate Zinc Distribution in Aggregates

Soil pollution with heavy metals like zinc causes increasing concerns about environment. According to distribution in soil, this study was conducted to compare zinc concentration between aggregate exteriors and interiors of some contaminated soils. Aggregates were collected from 5 depths of 4 soil profiles with different textures and were separated mechanically into exterior and interior fractions. Soluble and exchangeable and also bonded to carbonate fractions of zinc from both aggregate interiors and exteriors, were extracted and measured. The concentrations of zinc in both above fractions were high in the exterior part. Concentration of soluble and exchangeable zinc showed high correlation coefficient with soil pH and total concentration of soil zinc, also bonded to carbonate fraction of zinc showed high correlation coefficient with total concentration of zinc and low correlation coefficient with percentage of soil CaCO3.