Unusual water around the world and as a water source has many applications in arid and semi-arid areas. Due to the severe shortage of water resources in the country, implementation and operation of municipal wastewater treatment and irrigation in the agricultural sector, is an effective method to meet the water requirement of plants and reduction of environmental pollution. Purification with the help of plants and in particular phytoremediation, as a natural way, has been introduced to eliminate many pollutants. One of these plant species is Vetiver Grass that because of its unique physiological and morphological characteristics has great potential in the field of wastewater treatment and reclamation of valuable lands. In order to improve the quality of municipal sewage via Vetiver Grass and its hydroponic cultivation in effluent and evaluation of its effectiveness in, removing and reducing of nutrients and pollutants, and its application especially in small communities, this research was conducted in a completely randomized design with three replications. For this purpose, pilot trials were conducted with a net volume of 1000 liters which was intermittently fed for two months with the effluent from a domestic wastewater treatment plant. In this investigation closed system or Bach was used. Treatments included two plant intensities (4 and 8 Vetiver plant) and control (with no plants), aerated and non-aerated wastewater. In this research, retention time 3, 7 and 14 days were used. The results indicated that BOD 5 , COD, ammonia, nitrate, phosphate, potassium and coliforms were reduced by 42, 55, 91, 66, 89, 97 and 99 percent, respectively. It should be noted the retention time 7 days (except for BOD 5 ) had the best performance with no significant difference with 14 days. Keywords: Wastewater Treatment, Urban Wastewater, Phytoremediation, Vetiver Grass, Hydroponic Cultivation, Removal of Pollutants.
