CHEMICAL FORMS AND MOBILITY OF SOME HEAVY METALS IN SOME POLLUTED SOILS

Document Type : Original Article

Authors

1 Soil Science Department, Faculty of Agriculture, Cairo University, Giza, Egypt.

2 Soil and Water and Environment Res. Inst., Giza, Egypt.

Abstract

The present study was conducted to investigate the fractionation of some
heavy metals (Cd, Cu, Pb and Zn) and their mobility in soils affected by different
sources of pollution. The soil profile samples were collected from 3 sites from each of
EI-Gabal ELAsfar and Heiwan areas which received sewage effluent and industrial
wastes respectively for long time. The obtained results show that the soil pH and total
carbonate content (TCC) are slightly decreased as the irrigation period increased.
However, organic matter content increased.
The average percentage value of each particulate-bound metals species in
all studied soils followed the order: residual (26.10 - 48.32 %) > organic-bound (6.27
to 52.48 %) > oxides-bound (4.95 to 33.15%) > carbonate-bound (0.67 to 22.05 %»
exchangeable (1 to 6 %) of the total present in the soils.
The percentage of distributed fractions from the surface layers showed that
the deepest layer (100-120 cm) is amounted to approximately 20 % for Cd; 11% for
Cu; 6% for Pb and 14% for Zn in EI-Gabal EI-Asfar which ,S higher than in Helwan
which represents 15 % for Cd; 8.7 % for Cu; 3 % for Pb and 8% for Zn of their total
contents in the surface layer (0-20 ern), The movement of Cd and Zn are more
movable than Pb and Cu.

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