اثر شوری و لجن فاضلاب بر فراهمی و جذب فلزات سنگین توسط گیاه جو

Abstract

The objective of this study was to evaluate the effect of soil salinity on the availability and uptake of cadmium(Cd), lead(Pb), nickel(Ni), zinc(Zn) and copper(Cu) in a soil treated with municipal sewage sludge (MSS). Soil was salinized (2, 4, 8 and 12 dSm-1 soil paste extract) with NaCl + CaCl2 (1:1ratio), and incubated at soil field capacity (FC) for 1 month. The soil was treated with a 1.5 percent of MSS and incubated again at FC for 1 month. Before planting,soluble and DTPA-TEA extractable of heavy metals and soluble Chloride(Cl-) were determined. Then barley seeds were planted and, plants were harvested 10 weeks after germination. The plant indices (dry weight, heavy metal concentration and heavy metal uptake) were measured. The results showed that all salinity levels significantly increased soluble and availability of Cd, Pb, Ni, Zn and Cu. Soil salinity had a significant effect on concentrations and absorption of Cd and Pb in plant (P<0.05), but on the Zn and Cu concentrations and absorption had no significant effect. The results showed that MSS application, increased soluble and availability of heavy metals in soil and chloride ion has effective role in their mobility in soil. It concludes that the results can be used for the evaluation of heavy metal mobility in salty soils in which treated with sewage sludge.