Geochemical background and contamination level assessment in Tunisian and Moroccan Mediterranean coastal lagoon sediments
Duplay, J.; Semhi, K.; Bloundi, M.K.; Khedhiri, S.; Ben Ahmed, R.; Darragi, F. (2012). Geochemical background and contamination level assessment in Tunisian and Moroccan Mediterranean coastal lagoon sediments. Environ. Earth Sci. 67(4): 1201-1214. https://dx.doi.org/10.1007/s12665-012-1566-6
In: Environmental Earth Sciences. Springer: Heidelberg; Berlin. ISSN 1866-6280; e-ISSN 1866-6299, more
|  |
| Author keywords |
Global background reference; Local background reference; Trace elements;Enrichment factor; Mediterranean lagoons |
| Authors | | Top |
- Duplay, J.
- Semhi, K.
- Bloundi, M.K.
|
- Khedhiri, S.
- Ben Ahmed, R.
- Darragi, F.
|
|
| Abstract |
The calculation of enrichment factors (EF) enables estimating contamination levels of trace elements in lagoon sediments. It is based on normalization to a conservative element and to a reference material. This reference can be from the literature or from analyses of local sediments or rocks which have to be representative of the studied site. Calculations of enrichment factors were applied to Cu, Pb, Zn, Sc and Al measured in three semi-arid coastal lagoons, El Kelbia and El Meleh in Tunisia, and Nador in Morocco. For El Meleh and El Kelbia lagoons, EF calculations were done using the post-Archean Australian shale as global reference material, and deep sediments as local reference material. For Nador Lagoon (Morocco), the chosen global and local reference materials are the continental crust and the Gourougou volcanic body, respectively. The comparison between results of both methods of EF calculations shows that using a global reference from the literature induces an underestimation of the contamination level. The use of a local reference allows a more reliable estimation of contamination levels in the studied lagoon. It appears that El Meleh Lagoon is moderately enriched in Pb, especially at the mouth of Oued and near agriculture activities. The Lagoon of Nador is severely contaminated with Zn, Pb and Cu near mine dumps and in the vicinity of cities. El Kelbia Lagoon shows a high enrichment in Pb near garbage dumps and main roads and an overall low to medium enrichment in Zn. |
|
