Conclusive approach for evaluating bed sediments of Lake Nasser using different indices | ||
| Egyptian Journal of Aquatic Biology and Fisheries | ||
| Article 3, Volume 19, Issue 4, December 2015, Pages 23-34 PDF (666.68 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejabf.2015.2274 | ||
| Author | ||
| Mohsen Yousry | ||
| Water Research Center, Nile Research Institute, El-Qanater El-Khairiya, Egypt. | ||
| Abstract | ||
| The present study focuses on metals distribution in Lake Nasser sediments and the major objectives of this study are to define the sources of these metals and to select the best indices to be applied for heavy metals assessment. Superficial sediment samples were collected from 10 sites along Lake Nasser (from Arkeen section to Kalabsha section). Samples were detected by inductively coupled plasma for Cd, As, Cr, Pb, Cu, Ni and Zn. The results showed that, Cd and As recorded values were under detection limits in all sites and the trend of metals according to average concentrations follow the sequence of Cu>Zn>Cr>Ni>Pb. The average concentrations of these metals were 106.2, 72.1, 56.4, 50.7 and 18.2 mg/kg respectively. Environmental assessment of sediments pollution by heavy metals was carried out using different indices. Pollution indices are powerful tools for ecological geochemical assessment. The commonly used pollution indices by heavy metals in sediments were classified as two types; single index and integrated index. Four single indices of contamination factor (Cf), ecological risk factor (Er), sediment enrichment factor (SEF) and new index of geo-accumulation (NIgeo) were illustrated. Five integrated indices of pollution load index (PLI), degree of contamination (Cd), modified degree of contamination (mCd), sediment pollution index (SPI) and potential ecological risk index (RI) were also calculated. Based on these indices for identifying the level of heavy metals of Lake Nasser sediments beside applying statistical analysis (cluster variables); the sediment enrichment factor, sediment pollution index and potential ecological risk index were chosen as the best over the other indices. The results also indicated that Cu, Zn, Cr, Ni and Pb in the surface sediment were primarily derived from crustal origin and the natural processes, such as weathering and erosion of bedrock are the main supply sources of heavy metals in sediments along Lake Nasser. | ||
| Keywords | ||
| Heavy metals; surficial sediments; Pollution index; sediment enrichment factor; Geoaccumulationindex; ecological risk index; sediment pollution index; Lake Nasser | ||
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