Changes in the fractionation of Cd and Zn in composts of various compositions

摘要

The aim of this study was to determine the changes in Cd and Zn fractionation in composts containing sewage sludge, wood chips and grass at the beginning and after twelve weeks of intensive composting process by sequential extraction procedure. Zinc was distributed more into exchangeable fraction compared to cadmium. The highest amounts of both elements were found in the organic fraction at the beginning of composting. The portion of Cd and Zn in exchangeable, oxides and organic fractions decreased after twelve weeks. On the contrary, the portion of studied elements in residual fraction increased over time.