TP7 Metallic and Organometallic Distribution and Effects
201 Oregon Ballroom
1:20 PM - 4:40 PM, Tuesday
() Suspended matter and particulate zinc speciation in the Nozha Hydrodrome, an artificial lake feeding with contaminated Nile water.
SAAD, Massoud1, SAFTY, Alaa2, 1 University of Alexandria, Alexandria, Egypt2 University of Alexandria, Alexandria, Egypt
ABSTRACT- The Hydrodrome, covering area of 5.04 km2 and average depth of 2.11 m, is feeding by contaminated Nile water and is used as fish and duck farms, which possibly affect human health. Surface water samples were collected monthly from this lake for investigating the distribution of particulate zinc (PZn) species and suspended matter (SM). The feeding canal was not the main source of SM, which showed limited local distribution. Differences in SM composition in locality and season indicate its different sources. Five-step sequential extraction scheme was applied to SM to illustrate the contributions shared by individual Zn species in its total zinc concentration to ascertain the risk of zinc. The exchangeable fraction (Fl) was the least among other zinc species, giving poor negative correlation with pH and significant positive correlation with clorosity. Fl percentage did not pass 15% of PZn. The bound to carbonate fraction (F2) showed high significant correlation with organic matter/sulfide fraction (F4), indicating that metal carbonate had two origins, organic and inorganic. The peak of F2 in April coincided with spring plant blooms, which consumed most of carbon dioxide facilitating carbonate precipitation. The high dissolved oxygen and chlorosity affected the release of F2, as confirmed from its correlation with these variables. The highest monthly average value of Fe/Mn oxides fraction (F3) in February and June resulted from its highest amounts in the feeding canal in those months. The part shared by F3 in building up PZn was monitored via its positive correlation with PZn. F4 was the second smallest fraction in open locations, where water was well oxygenated by wind action, facilitating oxidation of organic matter. Dominance of residual fraction (F5) in feeding canal in most months explains abundance of this inert fraction in lake water. Similar to F4, significant negative correlation existed between F5 and SM .
Key words: lake water, pollution, zinc speciation, Nile water