Lab-scale phytotreatment of old landfill leachate using different energy crops

• Phytotreatment with oleaginous plants is tested for treating landfill leachate.
• Rapeseed, soybean, sunflower have been chosen for biodiesel production.
• High removal efficiencies of pollutants have been obtained.
• Nitrogen and phosphorous in the leachate have been used as nutrients for plants growth.
• Clayey soil proved to be more suitable for COD and nitrogen removal, nitrification was better in sandy soil.

Old landfill leachate was treated in lab-scale phytotreatment units using three oleaginous species: sunflower (H), soybean (S) and rapeseed (R). The specific objectives of this study were to identify the effects of plant species combinations with two different soil textures on the reduction of COD, total N (nitrogen) and total P (phosphorous); to identify the correlation between biomass growth and removal efficiency; to assess the potential of oily seeds for the production of biodiesel.The experimental test was carried out using 20 L volume pots installed in a greenhouse under different leachate percentages in the feeding and subsequent COD, N and P loads.Significant removal efficiencies were achieved: COD (ɳ > 80%), total N (ɳ > 70%) and total P (ɳ > 95%).Better performances were displayed by the clayey soil. Plants irrigated with leachate, when compared to control units fed only with water and nutrient solution (Hoagland solution), developed a larger plant mass. Sunflower was the best performing species.