الفهرس 
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Abstract
A simulated solution for the groundwater with different concentrations of Fe and Mn was treated using a laboratory set-up of an aerated slow sand filter. The upper surface of the filter was aerated as a novel technique for removal of Fe and Mn in a single unit. Low rate aeration ranging from 0.1 -0.5 m3 air /m3 water/ minute was used with
dissolved oxygen of 3.0 -5.0 mg/lit. Neither disturbance nor agitation was
produced for the sand surface during the system running. Concentrations
of Iron of 2, 4, 6, 8 and 10 mg/lit and Manganese of 0.2, 0.4, 0.6, 0.8 and
1 mg/lit were used in separate runs. Different filtration rates of 2.0, 4.0,
6.0, 8.0 and 10.0 m³/m²/day were carried out under steady state
conditions. By this configuration, removal efficiency of 98.8% and 69.8%
were achieved for iron and Manganese respectively without any chemical
additions.
The same aeration system was used to wash out the filter surface
by increasing the aeration rate, and its pressure. The water resulting from
the washing process was disposed from the filter surface directly. Air rate
above 0.5 m³/m2/min was sufficient to remove the dirty layer partially or
fully according to the air pressure. The scoured depth of the filter surface
was effectively controlled by regulating the air rate and pressure.