Increasing population growth and the development of agricultural and industrial activities and successive droughts in most countries in the dryland belt have led to intense of the water crisis, especially in arid and semi-arid regions such as Iran. In recent years the limitation of conventional water resources, the use of unconventional water to manage the crisis and the optimal use of permanent water resources have been considered by human societies. In this study, the performance of porous concrete as a bed and plant on reduction of urban effluent pollution has been investigated. A channel with dimensions of 9 meters length, 30 cm wide and 20 cm height was constructed along with the wastewater treatment lagoon of Isfahan University of Technology. Then, blocks were made of porous concrete with dimensions of 30×30×15 cm, and placed in the channel and the wastewater passed through the trial. The vetiver grass with two different densities were placed between the porous concrete blocks. After 5, 7 and 9 hours, the wastewater samples were taken from the inlet and outlet basins. The efficiency of removal of BOD, COD, TSS and total coliform during the five hours retention time were 16.05, 27.46, 20,57 and 19.07 percent, decreased, respectively. In the retention time of 7 hours, the removal efficiency was equal to 20.46, 32.98, 26.08 and 25.25 percent. The efficiency of removal of BOD, COD, TSS and total coliform during the 9 hours retention time were 25.86, 38.48, 31.91 and 30.54 percent, respectively. In general, this research showed the performance of system was optimestic in reduction of BOD, COD, TSS and Total coliform. Key Words : Wastewater, Phytoremediation, Porous concrete, Vetiver.
