The present study included the use of the aeration system in the treatment of gray water. Samples were collected from three selected houses in Mosul city in 2010 for the months (March, June, September and December). Some properties of grey water have been measured including pH, EC, TSS, DO, COD, NO3 and PO4. The aeration process has been carried out for the gray water for a detention time of two days in order to find out the best time for the treatment.
The results indicated a large decrease in COD 55, 76 mg/l after 23 hrs of aeration in March and June, and 51 and 62 mg/l after 25 hrs of aeration in September and December respectively. The remaining properties were examined at the end of the aeration process (at 48 hrs) which were within the FAO recommendation range for using the treated gray water for agricultural purposes.