Zotov V., Plekhanova I., Yakovlev A.

Fractional composition of heavy metals in sewage sludge and artificial soils compiled from sewage sludge

In sewage sludge and artificial soils with its use there is a high content of Cd and Zn, which compounds are the most mobile. The share of Cd in the exchange and specifically adsorbed fractions is 45-55 %. Phosphogypsum entering in sewage sludge and artificial soils has led to decrease in maintenance of Cd, Zn, Cu and Ni content in the composition of this fractions by more than half. The share of metals associated with oxides and hydroxides of iron, is minimum for Cd (8-10 %) and maximum for Cu (40-50%). The highest content of compounds associated with organic matter was observed for Mn (36-56%), and the lowest – for Cd (8-10 %). Phosphogypsum and lime entering in sewage sludge has led to decrease of the migration capacity of Hg and Cd compounds with drainage water.
Sewage sludge has a stimulating influence on growth and biomass of plants, but there is a high content of Cd, Zn and Pb in plant biomass. Ameliorants entering and dilution of sewage sludge with sand led to reduce of the content of heavy metals in plants of mustard, but the normative content was not reached.

Keywords: SEWAGE SLUDGE, HEAVY METALS, ARTIFICIAL SOIL, MELIORANTS