Mobility and extractability of heavy metals in contaminated sewage sludge-soil incubated mixtures

摘要

The use of sewage sludge for agricultural use is regulated in the European Community, but there is potential for its use as an organic substrate for the cultivation of ornamental plants in containers, providing phytotoxic levels are not exceeded. Mixtures of a sludge with high concentrations of Cr and Zn and two soils were prepared at sludge: soil ratios of 1:1 and 1:10 (w:w) and incubated at ambient temperature for up to one year. Metal extractability was assessed at various times using a sequential fractionation procedure.