Phytoremediation of landfill leachates

Municipal landfill leachate is a complex refractory wastewater which consists of extensive level of organic compounds, ammonia, and heavy metals. Contamination of water by landfill leachate has become a serious environmental concern worldwide due to its adverse impact on human health, aquatic organisms, and agricultural crop production. In recent years, constructed wetland (CW) has received promising attention in the treatment of landfill leachate, because of its cost-effective and eco-friendly nature and simplicity in operation, in addition to higher treatment efficiency. Hence, the present chapter is mainly focused on providing a concise discussion of the CWs and its phytoremediation attributes for the remediation of landfill leachate. Natural wetland plant species and short rotation coppice (SRC) have been introduced to remove contaminants from landfill leachate. Different processes such as phytoextraction, phytodegradation, phytovolatilization, rhizofiltration, phytostabilization, rhizo-redox reactions, sedimentation, adsorption, and complexation involve to remove nutrients (i.e., nitrogen and phosphate), heavy metal(loid)s, biological oxygen demand (BOD), and chemical oxygen demand (COD) to a great extent in CW systems. In addition, well-managed SRC systems save millions of dollars by eliminating the leachate transportation and treatment process which were earlier practiced. Further, there are a number of examples where phytoremediation has failed due to excessive leachate application and lack of management practices. Therefore, it is obvious that successful transfer of phytoremediation technologies from the laboratory to the field is a crucial step in terms of removal efficiency.