Variation of landfill leachate phytotoxicity due to landfill ageing

BACKGROUND: Landfill leachate is a heavily polluted liquid with important environmental impact. It can be generated in a landfill for a long time. During each phase of a landfill life cycle, landfill leachate with specific composition is produced and its treatment has to be optimized accordingly. Phytoremediation offers many benefits compared with conventional treatment methods. However, leachate can have a negative impact on plants and thus it is essential to evaluate the potential risk of landfill leachate for plants employed in phytoremediation. RESULTS: Phytotoxicity and composition of two landfill leachates were studied. Phytotoxicity testing and physico-chemical parameters showed that the leachate generated in the active part of the landfill was significantly polluted and more toxic to plants than the leachate generated in the closed part of the landfill, which did not cause any significant adverse effects on root growth of plants tested in soil. However, the highest toxic effect of both leachates has been observed in the first days of plant germination. CONCLUSION: Phytotoxic pollutants have probably been degraded in the closed part of the landfill and leachates from such landfills are not significantly toxic to plants. Therefore phytoremediation appeared to be an appropriate restoration and treatment method. Copyright (c) 2012 Society of Chemical Industry