Heavy metals removal from landfill leachate by using two-stage constructed wetlands planted with Limnocharis Flava and Eichhornia Crassipes

Abstract

Leachate contains contaminants consists of organic and inorganic material. An inorganic pollutants exit in leachate is heavy metal. The heavy metal or toxic inorganic chemicals most commonly found in Leachate is Manganese, Nickel, Zinc, Ferum, Lead, and Copper. Constructed wetland is one of the efficient methods to treat landfill leachate. Constructed wetlands are engineered treatment systems that make use of the same contaminant removal mechanisms applied in wastewater treatment plants that function in natural wetlands. The main objective of this project is to determine the efficiency of two-stage constructed wetlands which is Subsurface flow and Free water surface in removing heavy metals from landfill leachate and determine the amount of heavy metals taken off by roots, stems, and leaves of wetlands plants. Besides that, this study will also make the comparison of the efficiency of two species which are Limnocharis flava and Eichhornia crassipes in removing heavy metals in landfill leachate. Both plant have the ability to remove heavy metals from landfill leachate with the overall removal efficiency ranging, Mn (87.22%-96.32%), Ni (97.5%-98.5%), Zn (86.7%-100%), Fe (93%-52.6%). The highest efficiency of the systems was recorded for the uptake of Mn and Zn by Eichhornia crassipes which were 0.281mg/g and 0.069mg/g respectively. Conversely, for Limnocharis flava, the high heavy metal uptake is Ni and Fe. The concentration of Ni is 0.0021mg/g while for Fe is 1.128 mg/g.