Study Area: Study area of this research work is
located near a primary municipal wastewater
treatmentplant namely Abu-Rawash wastewater
treatment plant. The treatment plant is one of the
greatest Cairo wastewater treatment plants with a
treatment capacity of 0.4×10 6 m3/day. The plant receives
more than 8.5×106 m3/day so more than 50% of the effluent
leaves the plant after screening without any further
primary treatment. Water samples were collected
monthly from six sites as presented in Figure 1 and Table
1. Sample number 6 was collected from drain number 6
which is totally agriculture drain water without sewage
discharge. Two points (samples 5 and 6) had fish while
the others (samples 1, 2, 3 and 4) were totally sewage and
had no fish.