Document Details
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Document Type |
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Thesis |
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Document Title |
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SPECIATION OF SOME HEAVY METALS IN THE RED SEA COASTAL SEDIMENTS OF THE KINGDOM OF SAUDI ARABIA صور ترابط بعض الفلزات الثقيلة في الرواسب الشاطئية للبحر الأحمر للمملكة العربية السعودية |
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Subject |
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Faculty of Marine Sciences - Marine Chemistry |
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Document Language |
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Arabic |
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Abstract |
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The present investigation was carried out to study the distribution of some heavy metals (Cd, Co, Cu, Ni, Pb, Zn and Fe) in the surface sediments of the Saudi Arabian coast of the Red Sea. The partitioning of these elements between four geochemical forms using sequential extraction was also studied. The sediments were analyzed for their major characteristics including grain size distribution, carbonate content and organic carbon content. Sixty two sediment samples were collected from five sites selected to reflect the variability of population density and human activities. It was found that total heavy metals concentrations at sites of low population density (Site 1 at the northern extremity) were comparable to concentrations found in sediments of remote areas away of any pollution sources. Sediments showed increasing enrichment in heavy metals southward as the population density and accompanying human activities increased.
The four-step sequential extraction technique was used to determine the chemical association of heavy metals with the major sedimentary phases (1) Exchangeable and carbonates phase, (2) Manganese and iron oxides (reducible), (3) Sulphides and organic matter (oxidizable) phase and (4) residual phase) showed that sediments have distinct geochemical partitioning strongly related to the human activities. More than 65% of Cd, Co, Cu, Ni, Pb and Zn were held in the immobile residual fraction of the sediments at sites 1 and 2 of restricted human activities, while more than 50% of Cd, Cu, Zn and Pb were found in the first three fractions (mobile fractions) of the sediments at site 3. At sites 4 and 5, where the population density is the highest and huge quantities of different types of wastewater are dumped into the coastal area, the strongest mobility for all metals we observed; more than 60% of the studied metals concentrations were found in the first three fractions which are potentially mobile and could be released into the overlying water upon the change in the environmental parameters such as pH, redox potential or the presence of natural and synthetic chelators.
The metal pollution index (MPI), the contamination factor (Cf), the modified degree of contamination (mCd), the geoaccumulation index (Igeo) as well as Potential Mobility (PM) were calculated to differentiate between the natural and anthropogenic fluxes of those metals and to assess the contamination status in the sedimentary environment of the study area. The data obtained from these geochemical indices suggest that Sites 4 and 5 are the highly polluted sites and site 1 is still not affected by any human impact. |
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Supervisor |
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Dr. Adnan J. Turki |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1433 AH
2012 AD |
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Co-Supervisor |
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Prof. Dr. Mohammed A. El Sayed |
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Added Date |
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Sunday, June 17, 2012 |
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Researchers
| فكرى مرشد شاهر | Shaher, Fekri Murshed | Researcher | Master | |
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