Evaluating Performance of Different Filter Media Stratification for Tertiary Treatment of Wastewater

The use of treated wastewater for agricultural irrigation is one of the methods used to reduce the scarcity of fresh water. In this study, the different filtration media of sand, anthracite, granular activated carbon (GAC) and rice straw with a sub-base of gradual gravel supported each were used. In addition, the filtration efficiency was evaluated according to the treated water quality tests. As such, different filtration rates were parameterized to obtain the best operating conditions after ensuring that treated wastewater meets with the standard specifications for irrigation. The results indicated that the optimal filtration rate is 175 m / day, which achieves the appropriate quality of treated wastewater for the water characteristics examined according to the standard specifications of irrigation water. In addition, rice straw supported by a sand base is considered a practicable filtration media. However, the results of analyses of total solids in water did not match to Egyptian standards when using rice straw with sand as a filtration medium. Therefore, it is recommended to follow the filtration process using rice straw as a filtration medium with another stage of sand filtration to ensure the total solids comply with the standards.