CONTRIBUTION OF SOME TRACE ELEMENTS FROM AN EGYPTIAN HUGE DRAIN TO THE MEDITERRANEAN SEA, WEST OF ALEXANDRIA

CONTRIBUTION OF SOME TRACE ELEMENTS FROM AN
EGYPTIAN HUGE DRAIN TO THE MEDITERRANEAN
SEA, WEST OF ALEXANDRIA
OSMAN A. EL-RAYIS
1
AND MAHA A. ABDALLAH
2
1 Department of Oceanography, Faculty of science, Alexandria University, Egypt
2 National Institute of Oceanography and Fisheries, Alexandria, Egypt
Key Words: Omoum Drain, agricultural drainage water, up- and down-stream, trace elements,
Mediterranean Sea, Alexandria, Egypt.
ABSTRACT
In 2003 the MAP Technical Report Series 141, has mentioned lack in data concerning
flux of water, sediments and pollutants from North-African rivers and of course from the
land based sources to the Mediterranean Sea.
In Egypt, Omoum Drain, after the construction of the Aswan High Dam and controlling
of Nile River water flow, becomes one of the main land based sources regularly
discharging its waters (flow rate 2547.7 x 10
6 m
3
/year) directly to the Mediterranean Sea at
EL-Mex Bay, west of Alexandria. At its downstream part and before reaching the sea its
water mixes with water effluent (surplus water) from a neighboring sewage polluted lake
called Lake Maryout, rate 262.8 x 10
6 m3 /year.
The present work is a monthly study for a year for level of concentrations of mainly
some trace elements (nutrients and some heavy metals) in the proper water of the drain
before mixing and in the effluent from the lake and calculations of both the concentrations
and the corresponding expected loads of these elements contributed by the drain to the sea.
The results revealed that the respective load to the sea for each of total suspended matter
and for dissolved PO4
-P, inorganic N, Fe, Mn, Cd, and Zn is 77380, 427,
4745,237,3.28,5.84,2.9 and 24 metric ton/year. The elements loaded by the lake effluent
represent values ranged between 8 and 57.5% of the total load contributed by the drain to
the sea. The plant nutrients (ammonia and reactive phosphorus) are of values exceeding
44%.