Sustainable Water Management Solutions for Large Cities
(Proceedings of symposium S2 held during the Seventh IAHS Scientific Assembly at Foz do Iguaçu, Brazil, April 2005). IAHS Publ. 293, 2005, 264-272Impact of wastewater discharges from Alexandria on suspended matter and particulate zinc speciation in Lake Mariut
MASSOUD A. H. SAAD & ALADDIN M. SAFTY
University of Alexandria, Faculty of Science, Department of Oceanography, Moharem Bey, 21511 Alexandria, Egypt
saad@internetalex.com
Abstract The increase in total suspended matter (TSM) in drainage waters entering Lake Mariut has elevated TSM levels in the lake. Its peak in July coincides with abundant phytoplankton in summer. A five-step sequential zinc extraction scheme was applied to TSM. The exchangeable fraction (F1) was the smallest of the zinc species. That bound to the carbonate fraction (F2) gave a highly significant correlation with the organic matter/sulfide fraction (F4). The empirical regression equation was: F2 = 420.7 ± 187.8 + 0.896 ± 0.26 F4. F2 showed the highest peak in March, due to spring blooms of phytoplankton. The part shared by the Fe/Mn oxides fraction (F3) in building up PZn was monitored through their positive correlation. F4 was the second smallest after F1. The diminishing of the inert fraction (F5) in some months supported the increase in the other mobile, hence dangerous, fractions.
Key words
Lake Mariut, Egypt; metal pollution; suspended matter; zinc speciation