Performance of Vetiver system in complementary municipal wastewater treatment

Due to the severe water scarcity in Iran, using treated wastewater for irrigation purposes is an effective method to meet the water requirement of plants. One of the methods is phytoremediation. In this field, Vetiver Grass has received growing attention. The aim of the present study is to improve the quality of municipal wastewater by hydroponic Vetiver grass, for applying in irrigation. This research was conducted in a completely randomized design with three replications. Fiberglass tanks with a volume of 1000 liters were prepared, and then filled separately with two types of raw and treated wastewater. Treatments included 4 and 8 plant densities, control, aerated and non-aerated wastewater. Retention times of 3, 7 and 14 days were used. The results showed that the optimal density in the treatment of municipal wastewater by Vetiver grass is a density of 4. Moreover, the aeration and non-aeration process of the treatments does not have much effect on the measured parameters. It should be noted the retention time of 7 days (except for BOD5) had the best performance with no significant difference with 14 days. The results indicated that BOD5, COD, ammonia, nitrate, phosphate and potassium were reduced by 42, 55, 91, 66, 89 and 97 per cent, respectively.