Improving Isfahan Landfill Leachate Quality by Phytoremediation Using Vetiver and Phragmites Plants in Green Space Irrigation

Considering the severe shortage of water resources in Iran, the utilization of treated municipal wastewater in the agricultural sector is an effective way for supplying water requirement of plants and reducing environmental pollution. Phytoremediation is an environmentally- friendly method to eliminate many pollutants. Vetiver (Vetiver zizanioides L. Nash) and reed plant (Phragmites australis) are two special plants for phytoremediation because of their unique physiological and morphological characteristics. The present research was carried out to improve the quality of leachate by vetiver and reed plant and, using hydroponic system evaluate their efficiency in the removal of contaminants. For this purpose a pilot study (containers containing 200 L leachate) was conducted including two plants, two densities, four retention times (3, 7, 14, 21 day) and control (with no plants). All experiments were performed with three replications. At the end of each period, BOD, COD, nitrate and phosphate were determined and evaluated. Results showed that the amount of COD, BOD, phosphate and nitrate was decreased by 68, 60, 82 and 83%, respectively, for the vetiver grass after 21 days. Also, results showed that the amount of COD, BOD, phosphate and nitrate was decreased by 65, 30, 60 and 63%, respectively, for the reed plant after 21 days. Finally, the results indicated that the best density for the treatment of vetiver grass and reed plant was a density of 4 in a closed environment. According to the results of this study, the vetiver plant and the reed plant have good potential to reduce pollutants.