EFFECT OF CHEMICAL REMEDIATION ON THE BEHAVIOUR OF HEAVY METALS IN COMTAMINATED SOILS

Abstract

The present thesis deals with the study of heavy metals status, their chemical forms and behaviour in the soil samples collected from the studied areas (El Salam, Bahar Hadoos and Bahr El-Bakar), as well as it deals with the study of the effect of applying organic amendments like PLM and inorganic additives like RP and n-HAP on heavy metals behavior in soils with different contamination levels, the selected soil samples (El Salam, Bahr El-Bakar and Ras Sudr) and effect of adding these amendments on plant biomass and heavy metals content. The surface and subsurface soil samples (0 – 20) cm and (20 – 40) cm, respectively were collected from thirteen soil sites in El Salam canal, Bahar Hadoos and Bahr El-Bakar drainage areas; five locations of El Salam were selected to represent soils irrigated with Nile water after mixing and the rest was irrigated with drainage water besides, three representative samples were taken for experimental work. 1- Alluvial slightly saline silt clay-textured soil of El Salam. 2- Alluvial extremely saline clay-textured soil of Bahar El-Bakar. 3- Calcareous slightly saline sand clay loam soil of Ras Sudr. Analytical data shows that these soil samples are silt clay loam to clay-textured. And cation exchange capacity (CEC varies from 24.53 to 41.18 me/100 g soil). The soils organic matter content ranges from 1.09 to 3.19 %. Salinity of the saturation extract is commonly strongly saline (from 4.15 to 37.9 dS/m) except for subsurface layer of sites 2, 5, 6 and 9 which are slightly saline (EC ≈ 2.44 – 3.52 dS/m) while for subsurface layer of sites 7 &13 and surface layer of site 7 are non-saline (EC ≈ 1.52 – 2.00 dS/m), pH ranges from 7.01 to 8.08, indicating that the soils are slightly alkaline to alkaline.