El-Mex Bay is a part of Alexandria coast on the Mediterranean Sea. It is subjected to effluents contaminated with several anthropogenic materials including trace metals. One of these effluents is called Umum agricultural drain (rate 8x106 m3/d). The trace metals (Fe, Mn, Cu, and Cr) in their labile and non-labile forms were determined seasonally in El-Mex Bay surface and bottom water. The determination of the respective labile and non-labile forms was made using chelating cation exchange resin (Chelex-100) and total dissolved metal. Some of hydrographical parameters as (water temperature, salinity, pH, dissolved oxygen (DO) and oxidizable organic matter (OOM) were also studied. The relations between these parameters and the labile and non-labile trace metals were investigated. The results revealed that the order of abundance among the labile forms of the metals was: Fe > Cr > Cu > Mn. Also most of them displayed a negative relationship with salinity, indicating the role of El-Umum Drain as a main contributor of them to the Bay. Moreover, they were at contamination level overcome the background of Oceanic concentration (WQC) but were still lower than the hazardous one. The non-labile dissolved trace metals forms were of concentration values higher than the corresponding labile one and have the same order. Vertically, the high values were found in the bottom more saline water.
Key words: labile form, non-labile, trace metals, El-Mex Bay, Alexandria
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