A filed study was conducted in Abu-Rawash farm, Giza governorate, to investigate the accumulation of micronutrients (Fe, Mn, Zn and Cu) and heavy metals (Pb, Ni and Cr) in the sandy soils of this farm upon irrigation with sewage effluents for different duration upon 10 years.
The experimented area was represented through 15 profiles of sandy textured soils. Accumulation of studied nine elements was determined through the different soil layers at a depth of 60 cm downwards.
Results showed remarkable accumulation of the tested elements through both surface and subsurface soil layer particularly the most upper layer (0-5 cm). The lower increments of Fe, Mn, Zn, Cu, Pb, Ni, Co, Cd and Cr averaged 6.4, 1.1, 5.2, 1.6, 1.1, 0.20, 0.06, 0.05 and 0.02 ppm, respectively. Such results may suggest that percolations should be taken into consideration for usage of sewage effluents. Efficient pre-treatment must be conducted to reduce the high concentrations of the studied elements particularly Pb, Ni, Co, Cd and Cr otherwise their level may surpass the permissible limits and hence could be toxic. At the same time it is preferable to maintain the essential elements at suitable levels.
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