HEAVY METAL SPECIATION IN COMPOST WITH A VIEW TO ITS AGRICULTURAL USE

This work evaluates the chemical distribution of some heavy metals in a compost originating from solid urban wastes, following a sequential extraction procedure.
It was also considered opportune to subdivide the compost into different physical fractions by means of sieving in order to understand better the contributions of the various grain size classes to the total heavy metal content.

The compost was sieved, on the fractions obtained: > 2 mm (F₂), > 1 mm (F₁) and < 1 mm (F₀), and in the unsieved sample (T), besides total heavy metal content, a sequential H₂O, KNO₃ (1M) and EDTA (pH 4.65) chemical extraction, was carried out.

For all the heavy metals considered, the highest concentration is found in the finest fraction.
Of particular interest is the behavior of the Pb which increased of about 50% in the finest fraction compared to the unsieved sample.
The results identified this fraction as contributing most to the contamination of the compost by heavy metals.

International Symposium on Compost Recycling of Wastes

G. Petruzzelli, I. Szymura, L. Lubrano, B. Pezzarossa, S. Cervelli

https://doi.org/10.17660/ActaHortic.1992.302.37