Landfill leachate treatment using free water surface constructed wetlands

Abstract

Nowadays, solid waste management and wastewater treatment are the most important problems that we are facing. The amount of solid waste produced around the world is increasing at high rate as well as in Malaysia. Although there are different alternatives to reduce them or for their treatment and disposition, landfill is still the most common practice in developed and developing countries. However, the landfill method causes generation of leachate Landfill leachate refers to the liquid that seeps through a landfill site and enters the environment. Constructed wetlands emerged as one of the potential treatment alternative that employed emergent plants to remove pollutant from leachate. In this research, a constructed wetland was developed by using Limnocharis flava to treat the landfill leachate. Different leachate concentration (50% and 33%) was studied in the constructed wetland to compare the treatment efficiency in terms of pollutants removal in leachate and the efficiency of the system in different hydraulic retention time (HRT). The result shows a better removal efficiencies at HRT 3 days can be obtained in Cell B where the parameter are NH3-N, PO43-, Mn, Fe, Turbidity, and TSS (83%, 88%, 91%, 92%, 100%, and 98% removal). The highest removal at HRT 6 days are NO3-N, PO43-, Turbidity and TSS (98%, 98%, 100% and 90%) can be obtained in Cell B, while in Cell A the highest removal parameters are NH3-N, COD, Mn, Fe, Tubidity and TSS (93%, 91%, 90%, 94%, 100% and 90%). However, the highest removal of COD can be obtained at HRT 6 days in control unit of 94%. However, the laboratory result shows that the removal efficiencies for HRT 3 days and HRT 9 days have not much different.