Greywater is considered a new water resource because of water scarcity all over the world. Thus collecting, treating, and reusing it safely is critical for protecting the environment from any hazard. As a common application of greywater reuse, irrigation includes specific characteristics of the water that need to adapt a grey wastewater treatment technology.
In this paper, an advanced oxidation process based on Fenton's reaction was used to evaluate the greywater treatment efficiency by testing specific parameters before and after oxidization and determining the optimum chemical ratio between iron salts (ferrous sulfate) and Hydrogen peroxide (Fe2+/H2O2) and the optimum retention time to reach the permissible limits according to the ECP, 501-2005 (Egyptian Code No. 501 of the year 2005).
An experimental model including three glass tanks with dimensions of 30×30×50 cm was established. The model consisted of a primary sedimentation tank to allow total suspended solids to settle, followed by a tank for chemical treatment with Fenton's reagent where iron salts of 0.3 gm per liter and hydrogen peroxide with four different doses were added representing chemical ratios between Fe2+/H2O2 of 1:3, 1:4, 1:5, and 1:6 to determine the highest efficiency of the reaction, then followed by the collecting tank.
From the obtained results, it was concluded that the optimum chemical ratio of Fe2+/H2O2 is 1:5 for a retention time of 30 minutes to achieve the permissible limits of the treated greywater to be reused in irrigation according to the ECP.