The Cd mobility in incubated sewage sludge after ameliorative materials additions
A. Hanč, P. Tlustoš, J. Száková, J. Balíkhttps://doi.org/10.17221/3347-PSECitation:Hanč A., Tlustoš P., Száková J., Balík J. (2006): The Cd mobility in incubated sewage sludge after ameliorative materials additions. Plant Soil Environ., 52: 64-71.
Cadmium mobility in sewage sludge amended by four types of ameliorative materials (lime, limestone, bentonite and zeolite) incubated under aerobic and anaerobic conditions for eight months was studied in the experiment. The most statistically significant decrease of available Cd extracted by 0.01 mol/l CaCl2 was recorded in sludge between second and fourth months of incubation. As most effective stabilizers were found limestone and bentonite added into the sludge incubated under aerobic and anaerobic conditions respectively. The presence of air reduced Cd mobility in individual sludges more than lack of air. Cadmium was separated by sequential extraction into five fractions as water soluble, exchangeable, bound with Fe and Mn oxides, organically bound, and residual fraction. Sequential analysis showed decrease of Cd in exchangeable and oxide fractions in sludge treated by lime and limestone at the end of aerobic incubation. Cadmium was found in water soluble and exchangeable fractions in small portion, even so its content in these fractions was higher than determined in slighter 0.01 mol/l CaCl2 solution.Keywords:
cadmium; sewage sludge; incubation; limestone; lime; bentonite; zeolite; sequential analysis